Tuesday, January 31, 2012

Imagine the number of vague questions that I get sometimes

How to correctly ask a question.  Remember this site is intended for shop technicians.  So if you work in another field and really have no clue to electronics, your answer may as well be in Greek, if you do not know what I am talking about.  So please direct your questions appropriately.

Hope that clears up some details, that I am frequently asked.

Clear Examples of Problems
Model Number  DV9418 / DV6608DV9000 is a series
Works with Battery   will not work with AC
Works with AC  will not work with battery
Charge light   not on when plugged in
Turns on Shuts off
Runs but No Video
Runs but Dim Video
Only then can I possibly guess if I can answer your questions.  Not all of them may be answered.

New Month and Thanks

January was a busy month a lot of new. And donations were helpful, freeing me up to do record more projects. So as an added bonus for those that donated I will be setting up a Video Repair section - Via YouTube or another hosting site. There you can see various videos and exactly how I diagnosed and solved the problem.  Thought it might not be professional work it is clearly stated.  If you have donated and do not get the link, feel free to email me. (The volume of mail is quite high as well as me getting distracted on other projects).

Why don't I post daily?   [see profile]
Well I have other skills too - 

Electronics is what I like because it is a challenge. This Blog
Graphics and animation because it is interesting and creative. [Youtube]
Websites because I have friends in need sometimes. Basic Sites
Programming because sometimes things are not available that you need TCMS project

History  because the past should be preserved. I found an old High School yearbook in the trash and thought it was significant. Baltimore [MD] Western Girls High School [1800-1900's]
As well as painting drawing, photography and 3D Animation. When fully used a computer is an excellent tool for the creative.

So try not to be impatient when not responding.
And to all thanks again.  Keep on Fixing Stuff!

Friday, January 13, 2012

DV4-1255dx - No Video, Blinking lights on topside

Needle in a digital haystack - numerous problems

Damaged Coil Side view

Problem described as Memory Slot Not working & No Video

Since I had never seen this unit come on, with memory in slot 1 or slot 2 there was not much I could do other than thoroughly inspect the system fisrt.

Damaged coil Top View
1: Found that a coil under the PC Card slot was broken.
    Replaced and Test - No Fix

When peeling back the plastic near the Video connector- looking close I notice a cap is stuck to the plastic. Very small ceramic cap that was hardly noticeable without magnification.

Now- Where does if come from and where does it go?  What is it's purpose?

Under magnification, I view the area where the smaller components are and
see evidence of solder or tampering.  This appears to be the location of the missing/stray cap.

Since this is a multi-step repair...

Back to the work bench to see if the problem is fixed now.
Stray cap found near video conn.

Location of cap
Missing from pad
Replaced Capacitor

HP G60 No Power- Blinking Power LED

 HP G60 - No Power, Will not turn on, Will not charge

This unit arrives with No Power Problem.  When plugging in the AC Adapter I notice that the Power LED is (steady) blinking. The Power button does not work and does not light the charge light, so I can diagnose this as a major POWER IN problem. 

Inspecting the power section behind the DC Jack and the bottom side of the board.  Turning the board over, I notice a section burnt and a cap missing. 

So- the first thing I do is remove the caps indicated as 1,2 ,3 in pictures.
Then do a quick test- plug the power adapter back into the unit.

The power LED no longer blinks.  Cleaning up the area shows me that the cap indicated by #3 had severely shorted and the frayed metal end was also shorting the #1 cap. Removing the solder from the pad, and the welded metal from the missing cap, I have a working surface area to replace the parts. These are standard ceramic caps that can be found on an old board and nothing unique about them.

After cleaning and replacing all the caps in image, time for a final test. Voila!
The unit fires up, and because of the failure, or the unit sitting too long, the BIOS setting were lost or changed because I did not have the unit totally assembled, and peripherals were missing.  That is minor and when totally assembled the unit functions normally.

Solution: replace blown and shorted caps.
The cost is so insignificant that all 3 were replaced, rather than doing one at a time, which takes longer.

HP DV5-2035DX External Video, No Video on LCD

Click for larger picture view
DV5-2035  No Video, External video works fine

A DV5 arrives with complaint- 

Video shows on External but not internal video on LCD/LED display.

Inspecting the unit near the video section, 
the problem is immediately spotted as being a blown transistor. This transistor is one of the switching type that allows the video signal to be displayed/sent to the display. Without this part there will never be any video shown, except on an external monitor.

Click for larger picture view

Solution: replace blown transistor

Toshiba L455D - Previous repair attempt by another tech

Toshiba L455D - Board Damage

Ok so Monday starting off the week I get in a Toshiba L455D and say to myself "this should be easy" since I just had one last week and things went pretty fast. Taking the motherboard from the chassis I immediately see that it had been worked on by a 'hack', unexperienced tech.  Checking my previous notes to see exactly was was damaged I did a side-by-side comparison.
The way this board arrived and parts missing-
Click for larger view

Then I realize that there are simply too many parts damaged and missing to even get the unit back to the way it should be. 

So this is one that I will not attempt to repair simply because of the amount of time it would take, and the value of the unit.

Solution: Replace motherboard.
The way it should be with parts shown -
Click for larger view

Wednesday, January 4, 2012

DV7 Power On By Pass (version 1) - TIP

For the older version of the DV7 you can bypass having to connect the power panel by shorting PIN 9 to ground, this will turn on the unit.  Saving wear and tear on the ribbon cable and connector.

This model was a DV7-1150US