Acer 7741G (Intel I5, ATI 5470) - no POST, only backlight comes on - 99% time

Hi,

I go this Acer 7741G which was said to have a motherboard fault (non-tech description).

When I got it, it was not turned on for I'd say a week - maybe a month, maybe longer.

I turned it on, I did POST. Ran Ubuntu from a Live USB. All okay. Lucky me I thought.

I went on to buy a hard drive, put it in, installed Windows 7 x64. Still all okay. I run Windows Update, installed some drivers (no video drivers), and let it do the updates.
When I turned back to it, maybe an hour later, the screen was black (light black, as only backlight was on).

I shut it down, rebooted, same thing. Only backlight is on. This is the same now, on every boot - but one.
I disconnected all power, also removed battery, and let it sit there for an hour or two.

Then I rebooted, and for a second or so, I saw it POST - white letters on black background, but immediately, it went all (light) black again.

I tried to do the same over night, letting it sit disconnected of all power. In the morning, I hoped I'd at least would see it POST again, maybe only "partially" - no luck. Light-Black ever since, no POST.

Does anybody know what this could be? Is the ATI GPU dead? Maybe the GPU of the I5?

It does not POST, so I do not only not see any POST messages, it does not show any HDD activity as far as I can tell. Fan spins up, backlight comes on, that's about it.

Any ideas?

Thanks & Cheers

 

Hi, you should try signal with dvi or hdmi with external LCD screen. When it goes , then LCD screen shining or cable broken. Try also moving lid up and down, maybe you got signal.
Don't think so, the Ati card is broken. Next step you have take apart laptop and find problem...

 

Thanks, but I already tried that - no luck. No signal on external display with VGA.

Also tried to remove RAM. With no RAM at all, screen stays black. Then I swapped RAM, only having each single 2GB block. Display is then "light" black again.

So neither external VGA works, no is the RAM the problem.

Any other thoughts?
Thanks

 

After two days disconnected from all power, I was able to boot into Windows again. After a couple of minutes, the screen went grayish again ...

Now, when booting, it is grayish again, not booting anymore.

Nobody an idea what that could be?

 

Maybe the cpu is dying? Just a thought.

 

Maybe really this problem. Mb or vga broken.
Like i wrote before, you have to take a part components, repaste, and trying find problem visual. ( water, atc)

 

Okay, as you know, letting it stand for a few days, disconnected from all power, it booted up properly.

It also seemed that putting it in the fridge helped. I was able to boot it up in shorter intervals, keeping it in the fridge for a few hours compared to letting it stand around for a few days.

Anyway, I let it stand disconnected from all power for 5 days, and today, I booted and updated BIOS (from 1.05 to 1.26, the lastest).

I was might nervous, fearing it might black-out on me again during flashing. It didn't, all went well.

Good news is, I have it running here for the last 2 hours, installing drivers, Windows updates and also doing load tests with Prime95 - all well so far.

Fingers crossed.

I keep you updated, maybe someone finds this piece of information useful, later.
Cheers

 

I gave it away, the guy said it still had the fault - I never saw it, though.

The BIOS update sure helped, but maybe the problem is not resolved, completely.

CLOSED