Mk6 video pcb failures

[Gene.loader]

Hi team. Over the years I’ve noticed that most second hand dual screen aristocrat mk6 machines have a failed secondary video pcb. I know the fans fail and get noisey but is that the reason for failure, ie the chipset overheats etc?

I see the odd reworked pcb for sale on eBay, are these actually reworked ie reflowed chipsets or just eBay seller lies.

Anyone know the exact point of failure. I used to do component level repair for an IT company and have the skills and equipment to fix some of these if I know where to start.

Any help is appreciated
Cheers

[Shaneomac]

got about 5 failed ones at home myself. not exactly sure what the problem is but they stop showing up in machines. had some that reboot the machines also like a watchdog error so must be shorting somewhere. have had them fail when fans are working as well. I have noticed there is a couple of different fans around and have tried to put the ones with a silver tape on the bottom of the heatsink on the chip, seems it would have a better thermal property to me but i only have one working one left now.

have a few xp boards also with failed videos chips so just assume its the chip overheating and dying. was going to try thermal paste on all my boards but havent so far.

[Gene.loader]

I used to be involved in component level repair of early 2000s notebook pcbs. Most chipset failures at that period were due to the newer lead free solder that would crack rather than flex due to thermal expansion and contraction etc, about the same period as these were made so am guessing the same issue. we used to reflow the solder either with a IR machine or flow bath, sometimes a manufacturer didn’t want to pay for that process so they got the heat gun method. I’ve used this heat gun method on Xbox 360 and various arcade pcbs and had mixed success. I found a heat gun and laser thermometer allow me to give accurate heat etc. I’ve resurrected 1 video board out of 10 and it’s still going after 3 months. I only have 2 working video boards and also need a better solution.

[Trisail]

I see you are talking about video monitor displays. This may not apply but I will put my 2 cents in. I am sure both these methods would be damaging to screens, so just boards. I wouldn't put an lcd or led screen in either an oven or freezer.

Laptop bad video chip repair/reball procedure  - wrap board in tin foil, place in oven at ( I think 200 degrees) for ( I think 30 minutes ). Google for correct info.

I remember bringing a couple back to life a few years ago.

Guy at work Googled and found -  put it in freezer for X minutes/hours and that was supposed to do the same/similar thing as oven.  I basically told him don't believe everything he Googles on the web. He came in the next day and said it worked. He used the laptop for another year.
(maybe Ripleys believe it or not on that one)

Anyway, maybe it's all just urban myth??

Had to share.

Tony

[Gene.loader]

Haha, yup we are not putting the lcd assembly into the oven. It’s a very small video pcb, about half the size of a PC AGP card.

What does wrapping it in tin foil do? I assume spread the heat and maybe protect the plastic components.

I’ve seen actual real reballing in a purpose built facility, it was very time consuming but extremely effective with a high success rate