Tuesday, October 26, 2010

Gateway MD2641U - USB and Shutdown Problems

Gateway USB ports not read -


This Gateway MD2614U would not recognize the USB ports or devices plugged into the unit. The problem was found to be manufacturer packaging mistake.  Unit made by ACER in Taiwan has a large plastic cover on bottom of motherboard, but the surface mount resistors coils, and capacitors were not wave soldered well, so the bonds were not sticking to mobo, instead to the adhesive on the plastic. About 12-15 SMT parts were stuck to the plastic and had to be manually placed on the motherboard in their correct location for the USB ports to be read.


The original reason this unit arrived was black screen/no video. Similar to the problem with the DV series using nVidia GPU though this was an ATI Chipset, the Southbridge and GPU were reflowed to assure solderballs were connecting under the chip itself.


How did I find out this issue?  Near the USB connectors the resistors were identified by their circuit designation, in this case it was the 300 series. (R353, C323, L341 etc) so checking under the plastic many of the parts were from this circuit. (see closeup as example)


The size of these parts are about 4 sugar crystals in a square pattern.


One part at a time was removed, folding the plastic toward board to see where it came from, then removed and one lead was soldered with needle point iron. After all the parts were placed on the motherboard, flux was added to the area and the other lead was soldered.  After both sides of parts were soldered, the whole area was reflowed with low setting on heat gun.  This was done to center parts on pads and to evenly flow the solder, and to help reflow any additional parts that may had only one pad connecting and  not visible to magnification. Also it is the recommended 
repair process to correct solder defects. (corrected solder
is shown in the lower picture)


Scotch tape was placed over the adhesive to keep additional parts from sticking again-notably the parts in the 200 & 300 series circuits. (The 200 series parts were used for the card reader to left)


To remove the parts from the adhesive, the tweezers were slightly heated to make it easier for the release from the sticky bottom. Be careful not to grip the parts too firm because they will fly from the tweezers and very difficult to find!


Good Luck!


Note: I've gotten another of the same model with different issues, this solution will be posted when opened.

Friday, September 3, 2010

More updates coming

Having been busy has kept me from updating regularly. Now it's just a time management thing. So further updates will be forthcoming. This weekend is a long weekend in the U.S. hopefully I can post more repairs.


Compliments with an ad, is still SPAM


I would like to ask readers not to post Spam links unrelated. But if you have a post on how to fix something feel free to post. I don't think many readers do not want Generic Viagra, Retirement Home in Costa Rica or discount batteries in France.  So don't be a Blog Troll posting advertising. That is annoying, and I'm sure you would not like me to make an issue of that. Because it will make me require membership, and confirmation emails before you can post. That effectively reduces communication and answers that many people are looking for.

Monday, July 26, 2010

Acer 5516 - Dead, No Power, No Lights

Finally a breather before the storm came. (Load of work)


This jack was damaged by drop and or push. The lead broke/shattered as if it was hit while running. Copper can shatter too, you know.


This should be clear enough LarryS.

Saturday, July 24, 2010

Acer 5515 Works off Battery, Charges, but will not run off AC

This unit arrived working from a charged battery, but will not power on from AC. 
My first thought was bad leg on the DC Jack, Easy job! Finally


Upon opening the case and removing the keyboard I saw the beginning of the failure. Burnt MOSFET under the keyboard directly behind the battery connector.


So took the rest of the panels off to see how bad it was. Out of a scale of 1-10 with 10 being the most difficult I rate this as a 7.5 because it was more annoying than difficult. The copper under the MOSFET was actually welded to the legs of the FET, heating solder would not break the weld.














Click to see larger image
The visual shows almost the worse case scenario for a shorted MOSFET. Burnt and totally unreadable numbers.  Seeing the circuit I surmised that it was an identical pair of chips but I had to verify against another motherboard to be sure.  Also there was a scorch mark under the keyboard, but it didn't affect the keyboard or any keys.
















Removing part and making a copper bridge for the legs of the replacement MOSFET was a little challenge getting it right and isolating it
from the center plane of the motherboard if copper was exposed. In this case a small piece of mylar tape will be placed under the copper retrofit.














Sizing and fitting the copper 'jig'. This was made from thin copper foil and cut with exacto knife and placement test made to see if the Gate lines were shorting or any other pads before making it permanent and not being able to remove it. 














Replacing the MOSFETs and soldering broken traces. In this case the  GATE line was blown away on both FETs so I got 2 small segments of wire and made the necessary bridges to the GATEs.




















Soldering the Gate line and cleaning up.  Now if you wanted to be fancy you can cover the solder and copper with some green fingernail polish, or clear polish and use a green marker over the polish after it dries. Then the repair will appear less noticeable.  


Notice the line at marking PR152 which was not so clear as being broken because it goes under the chip.




After doing all this I tested with the battery in place and with AC before closing up the laptop. No worse feeling than to have to redo after assembling things thinking you are done. ARRRGH It happened to me and so I started testing before closing.


As always you can click an image to see a larger version of it, and use the BACK button/Arrow to return to the page. Conversely- Shift and Click works best and automatically loads image in new browser.

Thursday, July 15, 2010

Compaq 6735b - Dead No Lights

This was a strange cookie. 
This unit showed no sign of life and was a weird design for power in button. 


I have to admit this was a 'lucky' repair. While diagnosing where was the DC power, I discovered that a power MOSFET was open, No Power anywhere, no lights, no charge and stone cold dead.


On the bottom of the board it was a mosfet FDS6676 that was open.  When I replaced it with a substitute I was able to follow the DC circuit, but it dropped off at the power button. So testing that area I noticed that when I put the meter positive on point on the board the light behind the pwr button would flash briefly.


Recalling a similar experience where I had to modify another CPQ 6735 when they first came out/released. I thought I would try my luck again. 

1: With the meter set to VOLTAGE and holding the meter's positive lead on this point, the unit would come on. My first guess was 47k Ohm. This worked but the laptop would not turn off, or would come on when it wanted to.
2: I would need another meter to see the resistance the meter itself presented. This turned out to be near 100k Ohm. Getting another 100k Ohm chip resistor from a dead unit, then making the leads, and adding clear heatshrink to insulate it from shorting. 
3: Always test thoroughly when out of case. This way you won't have to redo, or find out something else don't work.






First picture show resistor with background for clarity. The leads were added because there was no 'safe place' to tack to board. The white connector in picture is for the power button ribbon connector.


Click pictures for larger view














This shows placement where the part will lay. Heat shrink will be slid over resistor and hot glued down.


















Hot glue holds part and wires to board. Makes it easy to remove additional work is needed later. This area is covered with a L-shaped piece of black plastic insulation sheet 
Final and ready to test again and then close.
















Personal Note:
I always wondered why my high school Math/Algebra/Calculus teachers said 'Show Your Work'.  I was one of those students that seen solutions in my head, and couldn't always say, tell why or how I got I got the answers. They were just visible in the front of my mind.  Besides how can you explain something when you don't know the terms/rules and conditions of an equation, before you are taught 'the normal way'?


I quit that calculus class because I couldn't show the work, I didn't flunk I just quit it and picked another advanced science.  Their loss not mine.




Sunday, July 11, 2010

DV6000/DV9000 Lines in LCD and External monitor -unreadable

A fairly common problem with this series is lines in the LCD and external monitor. Sometimes it will exhibit scrambled characters on the screen. Similar issue.  This is because the video memory has fail or lost connection and the addresses cannot be read properly by the system. The rest of the system may work but video is not proper and screen unreadable.



Lines and streaks on POST screen
Should show BIOS info and CPU info
         


This shows the step by step on how to correct this problem. There are other videos on YouTube dealing with the 'no-video' issue. Some are dangerous, others are goofy. I will be getting back to that production.  Not wanting to knock anyone for trying, but be careful, some of these guys are not techs or engineers and have no clue of consequences. 

Thursday, July 8, 2010

Laptop Rebooting- DV6000, F700


While working on a DV6000 today I decided I should also address other problems with these models while working on the DVD production. 


As it seems this problem is also quite common, Rebooting, looping, restarting.  Never getting to the Windows startup screen.


OK there are several causes of this scenario with the ribbon cable being shorted or defective.  The ends of the ribbon cable can lift away from the surface when inserted and shorting the lead from the adjacent wire.  Some times it will short and cause the wire to burn. Other times it will cause the REBOOT/LOOP issue.  


Also verify that the Coin Sized CMOS battery has 2.5v- 3v, if not or voltage is low, all kinds of problems may present themselves.  Correct operating voltage is needed to read the CMOS data, or the data may be corrupt or deleted.


How to test/bypass these?
1: Disconnect the PWR connector cable, and turn the system on with the remote control (if you have one).  Make sure the battery is good in the remote.* 
2: Substitute with another cable.


Other issues presenting same problem
CMOS is bad** - If the CMOS is bad it cannot be read or written to- and the system continues to try to write/read data from it.


The Dual Channel MOSFET - one output is shorted or open. (or both)
When the MOSFET has about 3.25v on pins 1 & 3 it should be considered working. There should also be the same voltage on the Drain side (pins 5-8). This will take the voltage up to the legs on the PWR button and when the button is pressed this voltage drops to ZERO and the unit turns on.  The original part was a AO4812 and sometime has been replaced with a ME4920.


*How can I test the IR remote?
Since most people have a digital camera nowadays the cheapest and easiest way is to press the power button on the remote and look at the camera's LCD display.  You should see the remote blinking.


**How can I test the CMOS to see if it is working correctly
Disconnect AC adapter! 
With the ribbon cable connected to the power button, hold the button for 15 seconds to clear the CMOS. Now hold the PWR button down, and at the same time insert the adapter into the DC JACK.  The lights should come on for about 5 sec. then go off. Release the PWR Button. Now attempt to power on normally. Sometimes this works when the CMOS settings are bad.


Watch the orientation of PIN 1.
On DV6000 the leads are up 
On the DV9000 the leads are down
On the F700 the leads are down.
If your memory/recall is bad- take a picture before starting.


Note:  The black KOTEL ribbon cables are flimsy and the strain-relief/support is too close to the leads to help matters.  Remove and insert less often as possible.  If they break you'll wind up looking all over for a substitute. Though similar pitch and length cable can be found on GATEWAY MA3/7 touchpad. (Techs at shops should have a few of them around)  


Also the Gateway MA3 has two of the AO4812 chips on the back side near the 28 pin power output IC. Incase you were needing one. 

Tuesday, June 29, 2010

Format Change and Redirection??

Considering going to FORUM Format, this way dialog and content can be better grouped and followed.  This will stay up and be mostly for posts, but the forum will be best served for post and pictures that need to be answered.  The Blog only allows pictures at the beginning, and questions afterwards cannot post pictures.  Keep in mind this is intended for Technicians, and experienced individuals.  There is no way that I can train via the internet on how to do something. (At least not in the current format)

Since I see that there are lot of others that have been left behind, and some schools are not finishing the job.  I will try to outline and classify better on the new Domain.  You will have to subscribe so that I can at least keep track of my mail, questions and answers.


One thing I do ask, is Try to STAY on blog, direct questions to my email address misses hundreds of others that may want to ask the same thing, or are asking the same thing.  With so much time answering and 'teaching what a diode looks like' it consumes time that could be used for posting solutions.  


Thanks 
Don't forget to subscribe to this blog to be updated on the new site by email.  If not you would have to manually comeback and find the link.

Friday, June 25, 2010

Writers Block? Nahhh

Due to activity and being summer I had held off posting some items that had come across my desk.  So shortly expect a flurry of activity.

A recent email asked several questions that I think I can answer before hitting the grind again.

Do I do my own reballing?
No, the method I use corrects the solder balls.

The biggest defect of BGA and RoHS solder is tempetature and contraction of metal. Down on the atomic level, the valance bonds of the multiple elements used (in solder) break and you get a weak composition. Excessive heat causes metal to retract to themselves. So instead of getting a bond, you get contact.  Example: In the DV series, the breakdown is as follows.  After a period of time and use, the vents on the heatsink will become blocked.  This is from typical use and the placement of the Air In slots on bottom. They draw in fibers from pants, shirts, sheets, bedding, pet and human dander and carpet. Often larger than the vents exit. As more and more collects the vents become blocked.  So the fan runs longer (also collecting more lint faster). this in turn causes the CPU Heatsink compound to breakdown and dry out making it brittle and hard, and unable to do it's job. When the CPU overheats- it shuts off. May loop and repeat. All during this time, the GPU is overheating too, and the solderballs are expanding and contracting.  If there was a poor contact that was simply smashed down to make an electrical connection (and held down by heatsink screws). A 3-12 micron gap can occur on a non-whetted pad. Note: human hair is about 40microns.

Where do I get my schematics and chip info:
Additional costs and searching for schematics is a waste of time for me. I guess you can say I am 'old school'. Schematics can help, but between the Chinese manufacturers and the US branded companies. They try to lock up the information and it is not readily available in most cases. (I will point out sometime that many designs are meant for failure and not intended to be repaired) This I have proof. So you wind up spending 2 hours looking for a schematic. And then the manufacturer change suppliers, the suppliers change part numbers.
Example: in the DV6K/9K the mosfet switch for the charge/power went from AO4407 [Alpha and Omega] which was a hard company to locate, then switched to an AO4430, then to ME49xx or something of that nature. All this before many US part stores got the first version.

So what I do is read the specs for the individual part and get an Fairchild substitute list. Like the FDS6679 [Fairchild]is substituted for the AO4413. My favorite suppliers are Digikey, and Newark Electronics. As well as direct from the manufacturer such as MAX8734 [Maxim]

Liquid Spills
Are typically done in a 3 chemical bath. The first bath (after removing CPU and many of the stickers as possible) is done with boiling hot water [pure bottled] No Dasani or any water with mineralsBelieve it or not Aquafina works for me- This loosens and cleans most sugar based spills such as Wine, Cola, Tea and Milk. And let it soak until the water cools. Then depending on how great the spill, I will soak it in isopropyl alcohol completely covering the board. Then rinse again with boiling water, and alcohol again. Then allow to sun dry- we have plenty of sun here in Carolina.  Less sunny climates can put in Oven at 225F for about 20 min. [NOTICE that is Fahrenheit not Celsius] No higher! It is a motherboard, not a frozen pizza. Alcohol in Ultrasonic tanks works, but everyone does not have access to them, or the money. And they still should be rinsed with pure water. You can use compress air and blow much of the water out and speed up the drying time.

How do I monitor temps:
After a number of years you tend to learn tempetures by the chemicals used. like water boils at 212F.  Smoke and oxidation points of fluxes are somewhat ingrained in me from memory and 20+ years using them, when it smokes, it has reached the oxidation point.  You can use/get an IR temp probe if needed.

How to measure voltages, supplied to motherboards.
You test at the DC IN and to the largest NEG mass. Not to a heatsink frame or anything connected to the motherboard. The NEG may be isolated.

How Do I Replace LCD backlight tube.
I've stopped doing that now, the prices have fallen on most of the common screens 14.1 and the 15.4 so there are plenty around at low enough price rather than waste an hour replacing, when I could do two DC jacks. And most of the new 15.6" use LED so that problem is no longer.

Managing Screws.
This used to be a headache. Knowing and remembering which screw came from where. With the greater number being on the bottom cover.  So what I have done, is to use Scotch brand invisible tape over the holes. Same for most of the other locations that can keep the screws in place.  Beats having to guess which one is 2.5 and 3.0 then using the wrong length and causing a bubble on the wristpad or other visible place. OR even puncturing the plastic.  Another thing while on the subject.

You should not be using a cordless drill as a screwdriver. It over torques the screws, damage the brass retainers in plastic columns, or breaks the screw holder. You can get cordless screwdrivers for less than $10. Which will prevent further damage later. And have a set of mini-drivers (magnetic if possible).

Testing Caps
Sure caps can and should be tested, especially the brown ceramic caps. Most of the electrolytic caps give you a visible hint if bad. But do test them too.  You can use a Tweezer RLC meter for most of the tight places. Measures resistance, uHenry, and uFarad values. They run about 20-40 on eBay and the autoswitching are faster and better. So don't be too cheap and spend more time switching settings.

Do I read any other sources/blogs
No, that was my biggest headache and reason I started on this project, nobody that has experience and deep details on their findings are reporting much.  The techs are simply not journaling/chronicling their findings.

Trying to find a specific answer in a Forum is a nightmare. You ask a simple question and you get 25 people that want to tell you about their puppy, mother's flower garden and you never a direct answer. Then others tend to throw in questions totally unrelated. You're asking about HP and they say they have the same problem in a Gateway.  The moderators are not moderating, and thus the whole technical field has become as 'Babelized' as the Chinese parts industry.

Do I use diagnostic software
If is a particular dog I will use Belarc. But most of the time I only deal with electrical/electronic issues.  When it is working right Windows will tell you if there are problems. 
No USB but all the drivers are loaded and a Keydrive will not light up or access- I check the ports (visable inspection), USB controller chip or the data driver chip.
No audio - check the plug, and the audio controller chips.
etc...

Hope that's enough for now, will unload camera soon, so you can see some of the dogs! that I had to work on.

Friday, May 21, 2010

IBM Thinkpads No video, No P.O.S.T. Models T40, T41, T42

Advanced Notice:  I will be detailing the method on how to fix Thinkpads - No video No POST issue.

This is a quite common problem with the T-Series.

1: The system lights up but nothing shows up on the LCD
2: Nothing shows up on an external monitor
3: Hard Drive does not initialize.

What makes my method so much better?
You do not have to totally disassemble the whole laptop  (a major time killer). Only need to remove keyboard, and wrist rest.
You will not misplace screws and use the wrong screw holes!
Following directions it will work the first time!

So if you don't have the readily available items here is a brief list to get them ahead of time.
Heat gun, similar to those used to heat shrink insulation on wires. 
  At least 500 watts I got mine at Harbor Freight and used on LOW
Radio Shack Paste Flux $6.99 (mentioned in another section of this blog)
Two pieces of thick aluminum foil 4" x 4" (10cmx10cm).
    This it to make a heat mask so the plastics are not melted because it is not totally disassembled.

Small bottle of Acetone, not alcohol, not MEK, not gasoline!
Small Nylon toothbrush (with nylon bristles) - It has to be nylon, acetone will melt plastic.
Paper Towel for cleaning 


Step by Step with video (I hope) since I use 2 computers for blogging and my virtual life, I will have to juggle things or get the KVM switch out the bottom of a box. Since the video conversion and animation stuff is on the 'slow' machine.  And the Video Input Card requires XP and will not run on Vista/Win7. (yeah I know, but XP was a workhorse for 10 years, and not ready to buy more hardware for another OS)

Delayed   :-(  
( only a couple of days)
It's been a busy week.  Burned out my own heat gun. Will have to get another, but the info will be posted. Have camera set up, everything prepped and turn on the heatgun~ no heat, no hot wind!  Arrrgh


Mar 24, 2011 - Update and clariflcation




The above article was later covered by overlapping posts on the DV Series.  
As far 

as the average person being able to do it, that is not likely.  The tools 
needed and experience exceeds the value of the machine itself (unless you 
have serious data that you need to use or removed to another system).
The onset of the IBM NO POST/NO BOOT/NO Video is from dried 
heatsink compound (age). Clogged exit vents on the fan, then finally 
solderballs heating and shrinking until there is a separation from the 
motherboard contact.  Virtually all the connections are needed so you 
get a failure of data and signal lines with no voltage or current to allow 


the POST process to complete. With no information from CPU to GPU 
the video will not initialize.
This blog post was not finished because it was addressed in general form 
by the more popular DV series. See May 16th, 2010 which the exact same 
cause though in a different machine.  Some times when I try to provide 
information on my solutions, some people will attempt to do this themselves 
and mess up there machine even more.  Taking shortcuts on what I do is not 
an option and I've had to have a number of failures before discovering not to take 
short cuts.  

Example: if the complete motherboard on the T40/41/42 series is not 
removed the plastic channels that route the WiFi wires, CMOS battery holder 
are melted. Then the top panel cannot close properly, or the keyboard does 
not sit correctly in it's place. The method that can be used is the same as fixing DV9000 video memory. And I strongly caution to follow instructions if done by non-technicians.  

Though with the IBM GPU having a larger surface mass and different material it will use a little more time with the heatgun.  An additional caveat is the GPU can slide or shift if it does not have the hotglue spots that anchor the GPU to the motherboard. You must use flux, this removes contaminates, cleans copper pads and allows heat to flow properly around the solderballs which you cannot see. Overheating will kill the laptop



---The Laptop Doctor

Sunday, May 16, 2010

What is causing the DV Series to fail prematurely?

I have seen dozens of 'solutions' and fixes for the DV series and none really address the root causes. Others damage or ruin motherboard. Below are some of the weirdest solutions I have seen:



1: Placing a penny between GPU and Heatsink.
2: Using a copper shim (only slightly larger in area than penny)
3: Excessive thermal compound
4: Wrong type of compound.
5: Placing a tea candle (in aluminum holder) on GPU
6: Putting Motherboard in oven
7: Pressing down on GPU real hard
8: Reflowing without flux?!


Outline what each does and why it still fails later.

1: This will increase the pressure on the GPU when held down with 5 screws, a temporary solution, but does not remedy. Provides no greater heat dispersal and only transfers heat through penny. Metal fatique may damage the 5th retainer screw and not support the GPU.
2: Copper shim does the same as above.
3: Spreads heat over a larger area but does little to cool.
4: Does nothing
5: Can accidently cause more damage, and is only a temporary solution, because the holder never reaches the tempetature that RoHS solder melts.
6: Could ruin board, plastics, labels and fan/USB and other connectors. Dangerous & Risky
7: A temporary solution that fails later because the two surfaces only contact, not bond.
8: Sometimes work, but solder may be tacky under GPU and no way to tell. Not recommended.


Typically it starts like this.

After about a year of average daily use (and shortly after warranty expires) the vents on the heatsink would begin to clog. This lint builds up over time. If you have new carpet, rugs, lots of activity, kids, pets, dust and smoke, the time may be shortened.

The operating temp starts to rise over time because of the lack of ventilation. Chips run hotter, fan stays on longer drawing even more lint. Eventually the solderballs lose contact with pad under GPU. Any oxidation prior to the manufacturing process only attributes to loss of contact.

This can also happen with the Southbridge chip if it too had oxidation, causing various problems such as no WIFI, keyboard, touchpad and USB not working.


The Solution:

1: Reball the GPU (if possible) if not continue...

2: Reflow the GPU with proper tools, flux, and temps

3: Verify silicone pad under GPU heatsink


4: Replace aluminum pad under CPU heatsink with copper and apply thermal compound.


5: Disassemble Heatsink and clean


What doesn't work.


Holding down the power button while battery and AC removed. Clearing CMOS. This only re loads the factory CMOS info from ROM


Water based flux. Usually clear and sold on ebay to fix X-boxes
The liquid solution is too thin and heat used evaporates the liquid needed before the de-oxidation process begins. This is used in manufacturing for thin component motherboard during the wave solder operation. Works in manufacturing for thinner boards, but not for this process. Plus sometime conductive and may create short under GPU or chips if all is not dried.

High viscosity flux. Muratic Acid based. Sometimes listed as Liquid Rosin Flux but too thin and does not stick to pad during de-oxidation process

Blowing lint back into laptop with can of air. The lint needs to be removed not blown back into the machine, it only collects back into the
fan/vents.


What Does Work.


Reflow GPU for video issues
Clean Heatsink Fan - Always when the system is opened.

Rosin Flux petroleum based sold in paste form. Usually in a semi-gel state, but liquifies when it gets warm. Sticks to pads and when heated, and slight smoke indicates de-oxidation is happening. When the flux smokes it is also cleaning the contact pads making a larger area for whetting. I have done this and it works!  It is non-conductive and will not create shorts under chips.


How did I test?
I took an old motherboard where exposed
copper was oxidized and discolored, then
applied rosin flux paste. Heated the area to
tempetature that solder melts and when it
started to smoke, removed heat and allowed
to cool. After cleaning the area with acetone
the pad was bright like new.


ASK your tech "What are his qualifications?"
A+ Tech is only certified to replace peripherals and reload Windows, drivers, no soldering is taught.

Computer Techs - 2 year degree in computers, but no electronics training.

Geeks - only have experience, no formal training. Formal training is needed to be able to ask questions when you have them. Otherwise you guess at your own questions. Similar to hackers but no hands on hardware.

Hackers- The true hacker, (not malicious programmer). They build things and have experience soldering, only some of them have formal training.

Electronic Techs - 2 year degree and some soldering.
 

DV9000 Overheating

A DV9208 arrived with overheating problems. Luckily it was caught before it started generating additional issues with the GPU.


Symptoms:
Unit would overheat, cause shutdown/off without notice.
WIFI would turn off
Cause:
Heat sink vents 75% blocked, so insufficient cooling was the culprit.
Repair:
Disassemble unit, disassemble heat sink, clear vents.
Problem #2 was a little more different. Because the Southbridge
would also overheat, causing loss of contact on solderballs.

Solution:
Clearing the lint from heatsink will remedy issue with overheating/shutdown. Since no drive arrived with unit a substitute drive was used to run system for several hours, then turned off, and test again.  I do this about 4 tests so that nothing happens when it gets back to the customer.


Aluminum heat transfer pad for CPU
replaced with copper pad.  The pad
from HP is only ok, but many times the CPU gets so hot that the Aluminum breaks down and sticks to the CPU. Not providing a good thermal transfer.

Reflow process is done to both GPU and SouthBridge. 60 day Warranty offered

Wednesday, May 12, 2010

Back from vacation

Since I was out and about, all the time reading news, features and other tidbits from technologists, I decided I would make some observations.

Hype vs USE
iPad and the real world. Sad to say this unit does not live up to the hype. It is small lightweight and does view the web, but the bad points exceed the good for PC users to jump on the bandwagon GUNG-Ho.

1: The lack of USB on the unit requires additional costs.

2: Using 3G is out of the question unless you pay more. If you have a 4G service such as Clear.Net you cannot even use it. Why? Because it is an x86 install and USB dongle.

3: The entertainment use is out of the question. It cannot view YouTube Videos (which uses Flash Video format -FLV) You cannot use NetFlix (which uses MS Silverlight), and No HULU (again FLV). So that means you cannot do much. Not even view ABC/NBC/CNN/CBS News sources. Such as the tornado pictures from Oklahoma.  Corrections: It seems that some sites are changing their whole direction and having to do HTML5 and MPEG video. I wonder how much additional cost and time is used to accommodate iPad users?  ABC - how much was it?  but then again you have the money, little sites that may be important don't.

4: Cannot view any of the ads that corporations paid hundreds of thousands of dollars to produce and pay to stream.

5: Adding pictures to FACEBOOK/MySpace/etc - requires add-in of some sort to attach camera, since it don't have a camera on it.

6: Responding to an email that has to be detailed and outlined is nearly impossible with the on-screen keyboard. (again, cannot connect a full sized USB keyboard, or portable rollup keyboard) Let's see the comments in about 4 months on the ipads. Also that the rest of the world that does not use the Hindu-Arabic alphabet is just about left out. Malaysia, India, Thailand I still am wondering about their comments.

7: Synopsis: this is a 'dumbed down' Apple product for the minority of users. Sure a million people bought the hype, but check some of the sources. There are quite a few already being 'resold' as used. Craigslist, eBay and Amazon from dissatisfied customers. There are 300 million plus computer users in the WEST, 1 million iPads sold is .333%

It is a 1998 WebPad, that's it. Not of much use to the tech savy users of the 21st Century. Sure I will get flamed from AppleFans but the truth is the truth! Would you buy a new car that wouldn't run unless you had to bring your own engine, or battery? NO

These were the same people that bought crap such as WEBTV (just before digital conversion), and the email pads with B&W LCD displays. I've used phones that can do more than the iPad. They just didn't have a 7 or 10" screen.

Forgot to add 1 more cavaet- All while you are connecting to the net, you are locked into AT&T. The fastest 3G network when 4G blows it out the water. Like advertising the fastest rotary dial phone when the rest of the phones are 10key. It is not a selling point. The ads are bragging about covering 90 something percent of the users, but America is a mobile country. We are not always at home, when you get on the road you'd be struggling to get a signal in Ogalala, Nebraska or Central Utah where your company or personal business sends you. there is a lot of open space in the US and you just may need to pass through it sometime.


Stay Tuned

Saturday, April 3, 2010

Important parts on DV6000 and DV9000 series

These are important parts if you are looking for shorts or opens on the DV series.

This image shows the location of the FDS6679. A common cause of shorts in the DV series.


When the power supply is plugged into the laptop and it shorts out/turns off it's usually caused by this MOSFET being shorted. Plainly stated. You plug the adapter into the DC Jack and the Blue Ring fails to light up, and the Power Supply shuts off. Giving no power to the tip. To reset adapter, unplug from AC (mains) and wait 15-30 sec. Then plug in again. The adapter is not damaged, since this is how it is protected.

These parts do not determine charge time or per centage.
The FDS6679 only closes to complete Positive circuit.  The AO4407 only closes when the battery is plugged in. As a test- Check the voltage of the Drain side (pins 5-8) with AC adapter and no battery - you should see 0 volts.  When you contect the battery you should have 10-14v depending on DV6000 or DV9000 series.

IF the AO4407 is open - The battery will not charge
IF the AO4407 is shorted - The unit will not come on

If the FDS6679 is open - the unit will not come on
If the FDS6679 is shorted - the AC Adapter will shut off/ No Ring light on laptop.


AO4407 when open, will not allow current/voltage to the battery charge section, so it will run off AC but not off the battery.  This is the same for both DV6000, DV9000 and F700 series.
Chip: Alpha and Omega 4407 - http://www.aosmd.com/

FDS6679 - when shorted, unit will allow you to plug in AC adapter without shorting the adapter. The ring on the Power In shuts off, the Adapter shorts and will have to be unplugged (from laptop) before plugging it back into the wall power(mains). http://www.fairchildsemi.com/
or http://www.newark.com/

Friday, February 19, 2010

My Review of 2 oz. Non-Spill Rosin Soldering Paste Flux

Originally submitted at RadioShack

This electronic-quality rosin soldering flux is mixed with petroleum jelly and ideal for electrical and electronic soldering applications.


Actually the best available

By TheLaptopDoctor from Charlotte, NC on 2/19/2010

 

5out of 5

Pros: Good heat control, High quality, Deoxidizing

Cons: No liquid version

Best Uses: Large Projects, Minor Projects

Describe Yourself: Professional

It does the job exceptionally well.

As a NASA/MILSPEC/AF soldering pro this is currently the best product available retail. Though wishing they had a liquid version available with needle dropper. I heat mine before using a dropper to have it in a liquid state for better flow control.

When it has to be exact

thumbnail

Tags: results using product

(legalese)

Friday, February 5, 2010

HP DV1000 - Dim LCD

Error in image Pin Number





This was a challenging dog of a repair, but after too many hours I had to give it up. Items checked, replaced or repaired. LCD cable - replaced LCD connector - replace and repaired Invertor - checked backlight - checked LCD - checked Lid Switch - checked The LCD was first checked with a known complete lid from another DV1000, the unit still showed same result. So backing up
  • checked the LCD connector first.
  • noticed connector had internal damage -replaced (same problem)
  • noticed motherboard pin 29 was also blown off motherboard - repaired (same problem)
  • lid switch check for open/close continuity - passed
  • backlight - passed
The conclusion is that that motherboard damage was greater than initially reported or known. Previous tech had made some minor mistakes, but nothing serious.

Toshiba A205- DC Jack pushed in


This seems to be a common problem on the Toshiba Satelitte A2xx series since I recieved two in two days with the exact same issue. The DC jack is being pushed into the unit.

The DC jack fits into a sleeve that should support the jack from being pushed in too far. However the hole in the plastic of the lower chassis is much too large and the user without looking forces the power plug. Breaking the sleeve that holds the jack itself.

Poor design by Toshiba on the lower frame.
Poor and weak plastic on DC Jack.
Insufficient plastic support.
Excessively large hole causing the user to break the supports.

Solution:
The jack can be hot glued onto the lower base of the jack and the left & right edges (not the back). Solves the problem most economically for the customer.

Dell XPS 14.1 Laptop (unk model number)



Unit arrived with dead battery.
Would not power on
No lights.

Not much information provided other than DC Jack issue.

This was not the case, the DC Jack was fine, the unit was simply not getting any power.

Disassembling and starting to trace the DC in section, the burnt section was immediately noticed. This coil (bad solder/blown pad) was a common problem on the E1505, E17xx series. So checking the coil power shows no voltage reaching the source side (pins 1-3) of the MOSFET.

The Coils bottom surface that contacts the pad was blown off so it was an incomplete circuit > Replace
Check Mosfet (out of circuit) - DEAD Short. >Replace

Dell Latitude B1300


Synopsis: Would not power on, would not charge

Problem: DC Jack

Diagnosis: The unit would power on with charged battery and run until depleted. When plugging in AC Adapter the unit would not charge nor any lights come on. NO Positive DC Voltage

Solution: Check DC Jack and replace or resolder. In this case only the positive terminal was not contacting motherboard. Reflow/Resolder Jack.

Acer 3690 Touchpad Buttons





Synopsis: Client arrived stated that he was leaving for Australia the next day and wanting to leave his grandmother the laptop after it was repaired.

Problem: The unit functioned properly except for the right click button.

Diagnosis: After testing I noticed that the button had no d├ętente click that indicates it was not being pushed in when the touchpad click was made. Disassembling the unit shows that the stub which presses the button had broken off. rather than replacing the whole top assembly and touchpad, the buttons were replaced from spares.

Original buttons were black, replacement button silver from Acer 5100 series.