Acer 8920g problem

[Rikintosh]

I recently purchased a defective Acer 8920G. I bought it, because years ago I bought an acer 6920g and managed to fix it at home, exchanging the nec tokin for 4x330uf caps.

However, to my surprise, when I took it apart, I saw that it was already without the nec tokin. Someone replaced it with 4x330uf .

The problem is, it doesn't show an image on the screen! There is no problem with inverter, it will not show video on the external monitor, hdmi, vga, svideo etc ... It turns on, turns the fan, turns on the illuminated panel on the left, but then it turns off suddenly, then turns on again, and stays permanently on without showing any image.

- already tested with other video cards
- already tested with other memories
- already tested with another flat and display
- already tested with another processor

I'm thinking of changing the capacitors again, but I didn't want to waste time, so I'm creating this post, maybe someone has already been through this and can help me, before I start destroying this motherboard lol


Just out of curiosity, I bought a 8930g, with a very similar problem, however, when connecting the charger, it turns on itself, and remains on without showing an image on the screen. He was also exchanged nec tokin (for someone else), but from what I read on this forum he requires 470uf capacitors, but in fact they put 4x330uf + 2x220uf capacitors on him.

[piernov]

Re: Acer 8920g problem

Post pictures of what the replacement capacitors look like.
These machines had a defective NVidia GPU, if it doesn't have white underfill it's most likely bad, make sure you try with a good compatible graphics card.

[Rikintosh]

Re: Acer 8920g problem

Post pictures of what the replacement capacitors look like.
These machines had a defective NVidia GPU, if it doesn't have white underfill it's most likely bad, make sure you try with a good compatible graphics card.

Yes, I've tested it with other 9500gt, 9600gt video cards, from other acer notebooks. No luck.


Images:

8920G:






8930G

[Michiel]

Re: Acer 8920g problem

Hi there, Did you manage to solve the problem like in the first post ?

I have 2 the same Acers here (the 8920g with ddr2) and a 8930g, ddr3 both not showing picture.

When it does power on itself it is just the CMOS battery empty, like most acers does.

about the acer 8920g not showing picture / not posting
I readed that the CPU core needs to be 1 volt + or higher.

I measure only 0.90 volts on the CPU ( and nec tokin)

Nec tokin is replaced for 4x330uF smd.

Do you know why the CPU is on low power ?
PowerGood singal is 3.3volts everywhere.
and replaced the bios.
I checked the CPU power IC and VSSSENSE seems to be shorted to ground ?? is that normal ?

[piernov]

Re: Acer 8920g problem

Post picture of NEC Tokin replacement.

VSSSENSE is connected to ground.

[Michiel]

Re: Acer 8920g problem

pictures

[Sephir0th]

Re: Acer 8920g problem

Maybe i'm wrong but this doesn't Looks Like a proper replacement of an NEC Tokin, when i compare e.g. with the attached Pic...

However i never did It so far...

[Sametbey]

Re: Acer 8920g problem

if you look at it from this angle. it shouldn't be a problem theoretically. He used 330ufs long. North should work on chip.

[Sephir0th]

Re: Acer 8920g problem

Ah, i See. So Maybe there has to be done some measurements around the PWM-Controller for VCore etc. Thanks for clarifying.

[Michiel]

Re: Acer 8920g problem

thanks, it's the 4th acer now which I have done the NEC tokin repair. The first was done not so well hehehe :-(
but they still work. this one doesn't

I tried a third processor, a Celeron now and this one goes up to 1.15 volts and getting pretty hot
so I don't think the problem is in the vcore voltage.
also tried 3 other videocards, 1 seems broken because the screen goes to full black immediately when pressing power. tried different rams etc etc
I set the bios back to the original bin, but no luck
all voltages are there

can it be a broken Northbridge ? a USB drive is not reading when plugged in

it goes on, 5 seconds later off...and then stays on

maybe I can bypass something ?