A resource for techs and shops wanting to go just a little deeper and increase their profit margin for repairs. Instead of buying motherboards for every problem they encounter simply repair the bad part.
You should be an experienced tech before attempting repairs.
This is considerably beyond the average tinkerer, hobbyist. Though it may look easy, there are a number of other factors involved and if you do not understand, you may get in over your head.
DV6000/DV9000 Lines in LCD and External monitor -unreadable
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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.
Interesting; thanks for that. I was surprised at how short a time was taken to reflow the memory chips (~37 seconds?), using the "low" setting on the heat gun I assume. I guess looking for the flux smoke (which doesn't show in the video) is the key to knowing when you have applied enough heat. Time to experiment with a scrap board, but a recommended heat profile with temps would be handy.
The chips are smaller and less heat is used. No smoke will be seen. Generally speaking the bubbles are an indication that the solder balls are heated enough. Just making sure that the bubbling effect does happen. That also removes oxidation and contamenents that you cannot see from the top side of the chip.
Awesome video ...good stuff as always. I finally broke down and bought a T-862++ a couple of months back. it has already paid for itself.
Have you had any luck with the infamous Compaq C700 power issue? Seems to get power only from a charged battery. DC jacks and harness all tested good. And Im getting the correct voltage readings at the DC in terminals.....
Its that "one" thing that i was never able to figure out and just cant let go. I'm sure we have all had problems like this that we never let go. I always welcome a good challenge, but im not to proud to ask for backup!
Damon: I don't recall having a power issue with C500 series, but I have camera full of pics and some are quite detailed. Others I forgot to post or was too tired when it was fresh in my mind.
Yes Larry it is the temperature not the time. Remember the smaller the mass the less time you use. You do not want to damage the chip by heat. The flux spreads out the heat evenly under the chip and in this case was not intent on removing oxidation, only fixing the solder bond.
Damon: I came across a C500/C700 with the power issue you mentioned. Since the board are similar DV Series, check the top side next to the Power In connector. If a cap is shorted it will misread the voltage settings. Will update you on where exactly.
I have lines in GUI mode(when HP logo is shown, "starting windows" and in operating system) and systematic green boxes in DOS mode. Can this solution fix this problem and if no then what you suggest me? Thanks!
Kaspars: That video should have shown how to fix your problem. If you also have same display on external video it is a Video memory related issue. There may be video ram memory on top and bottom sides of the board (depending on amount installed). Use water based flux and low temp reflow. Reflow one side and Test with external monitor before reassembling. If the results are the same reflow the other side.
Do not press on chips! Do not bump board. Do not overheat. USE FLUX.
Flux cleans oxidation, makes copper like new and bridges heat and makes the solder stick better.
+ I'm lost in these englisch terms. Is this that flux I need: http://cgi.ebay.com/Flux-Tacky-RMA-Water-Soluble-/110690157444?pt=BI_Electrical_Equipment_Tools&hash=item19c5a5c384#ht_1456wt_1165 If no then which flux from ebay is required? Greetings from Latvia! :)
1: it should be yellow, liquid or gell 2: it should NOT be clear (that is too thin) 3: it should NOT be water soluble (that is for wave solder machines)
For US viewers: this flux is available at Radio Shack http://www.radioshack.com/product/index.jsp?productId=2049774
I cannot repair laptops for you via the internet, I can only answer questions related to posts. This is because I have not had experience on every motherboard that is out there. Bear with me.
If you do need it repaired. Contact me for quote (US/CDN Only)
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 AO44...
The number one issue with DV Series is: Blank or No Video displayed. The number two issue is : (tied) No Wi-fi or Continuous rebooting After repairing a number of HP DV Series laptops. I wanted to isolate the problem and make it easier for me to fix, and have them stay fixed! So digging deep into them I can only come to a couple of conclusions of why they fail. 1: Manufacturing - Hann-Starr Either the oxidation on motherboard or the Graphics Chips. Since the failure comes in both versions AMD and Intel lines. And in Intel and nVidia GPU's it seems it could be at the factory. 2: Distribution - nVidia Could the transit time and shipping packaging be contributing to the oxidation on the GPU? On one unit after a number of reflow failures, I decided to remove the GPU and prepare to 'reball' the chip. Then and only then did I notice there was no solder on some pads. So that points the finger to nVidia. Oxidation is the culprit since the solder balls are put on a ...
Imagine the flow direction Source to Drain This is how I test FETS What I will try to do here is to provide a little insight on how to test MOSFET's in circuit the easiest way I can think of. Essentially the FET acts as a switch, and the GATE either opens or closes the switch. When power is supplied to Pin 4 (usually the GATE) it will either open or close depending on the type of MOSFET it is. The arrows shows the direction for reference when using a meter to test. Setting the meter in DIODE mode. On the N-Channel FET place the NEG lead on Pin 6/7 and the POS lead on Pin 2/3. You should get a reading of some value ~100 to 500 or higher. Imagine the flow direction Drain to Source On the P-Channel FET place the POS lead on Pin 6/7 and the NEG lead on Pin 2/3. Again you should get a reading of some value ~100 to 500 or higher. The reason I say pins 2/3 and 6/7 is ...
Interesting; thanks for that. I was surprised at how short a time was taken to reflow the memory chips (~37 seconds?), using the "low" setting on the heat gun I assume. I guess looking for the flux smoke (which doesn't show in the video) is the key to knowing when you have applied enough heat. Time to experiment with a scrap board, but a recommended heat profile with temps would be handy.
ReplyDeleteThe chips are smaller and less heat is used. No smoke will be seen. Generally speaking the bubbles are an indication that the solder balls are heated enough. Just making sure that the bubbling effect does happen. That also removes oxidation and contamenents that you cannot see from the top side of the chip.
ReplyDeleteAwesome video ...good stuff as always. I finally broke down and bought a T-862++ a couple of months back. it has already paid for itself.
ReplyDeleteHave you had any luck with the infamous Compaq C700 power issue? Seems to get power only from a charged battery. DC jacks and harness all tested good. And Im getting the correct voltage readings at the DC in terminals.....
Its that "one" thing that i was never able to figure out and just cant let go. I'm sure we have all had problems like this that we never let go. I always welcome a good challenge, but im not to proud to ask for backup!
Thanks for the video.
Thanks, for your time.
-Damon McZell
Lucky's OnSite Computer Repair
Clarksville, TN
Damon: I don't recall having a power issue with C500 series, but I have camera full of pics and some are quite detailed. Others I forgot to post or was too tired when it was fresh in my mind.
ReplyDeleteYes Larry it is the temperature not the time. Remember the smaller the mass the less time you use. You do not want to damage the chip by heat. The flux spreads out the heat evenly under the chip and in this case was not intent on removing oxidation, only fixing the solder bond.
ReplyDeleteDamon: I came across a C500/C700 with the power issue you mentioned. Since the board are similar DV Series, check the top side next to the Power In connector. If a cap is shorted it will misread the voltage settings. Will update you on where exactly.
ReplyDeleteI have lines in GUI mode(when HP logo is shown, "starting windows" and in operating system) and systematic green boxes in DOS mode. Can this solution fix this problem and if no then what you suggest me? Thanks!
ReplyDeleteKaspars: That video should have shown how to fix your problem. If you also have same display on external video it is a Video memory related issue. There may be video ram memory on top and bottom sides of the board (depending on amount installed). Use water based flux and low temp reflow. Reflow one side and Test with external monitor before reassembling. If the results are the same reflow the other side.
ReplyDeleteDo not press on chips!
Do not bump board.
Do not overheat.
USE FLUX.
Flux cleans oxidation, makes copper like new and bridges heat and makes the solder stick better.
I watched it some time ago but now it says "this video is private" Hope you will fix it
ReplyDelete+ I'm lost in these englisch terms. Is this that flux I need:
ReplyDeletehttp://cgi.ebay.com/Flux-Tacky-RMA-Water-Soluble-/110690157444?pt=BI_Electrical_Equipment_Tools&hash=item19c5a5c384#ht_1456wt_1165
If no then which flux from ebay is required?
Greetings from Latvia! :)
Hello! very interesting work, but how do I see the video? me that is private ...
ReplyDeleteThe FLUX should be petroleum based Rosin Flux.
ReplyDelete1: it should be yellow, liquid or gell
2: it should NOT be clear (that is too thin)
3: it should NOT be water soluble (that is for wave solder machines)
For US viewers: this flux is available at Radio Shack
http://www.radioshack.com/product/index.jsp?productId=2049774
Video now available for viewing
ReplyDeleteHi, Sir
ReplyDeleteHow can I see the video ?
thanks.