Multi Colored Horizontal and Vertical Lines On Monitor Upon Boot

Had a similar problem with an Acer Aspire 7520G laptop and found a

solution. For reading the solution only, just skip the comprehensive

text explaining the symptoms observed and the consideration and

troubleshooting done, and go directly to the end of this text. You may

find some clues in the text here, though.

Symptom: Multicoloured vertical lines started appearing and made the

computer stall, and the fan-area was extremely hot. Probably

over-heating I thought ! After cooling down 10min the laptop could boot

again, but stalled again after some time - again with multicoloured

vertical lines and a very hot fan area. After a few days the computer

could not boot at all - only vertical lines appeared, which actually

developed over a few minutes to a totally white/grey screen. Very

strange !

Troubleshooting 1: After de-mounting the fan I found a thick dust mat

partially blocking the hot air flow out of the fan. This was what caused

the overheating problem, so I hoped this could solve the whole issue.

But wrong ... still when booting, the monitor was only multicoloured

vertical lines.

Fear: New LCD or new graphics card or new laptop ?

Hope: However - with an external monitor the laptop could boot though,

but only in "safe mode". I found out that the primary graphics card is

not used in safe mode - instead an on-board "vga-safe" card is used. For

some reason this "vga-safe" card cannot be used on the build-in LCD in

the laptop, so the external monitor was needed here.

Troubleshooting 2: Graphic Card problem or LCD problem ?

In safe mode I deactivated the graphics card in "device manager"

- Doing this, the laptop could boot normally in Vista with the

external monitor. Here the "vga-safe" card was used again

(automatically).

- Without the external monitor the laptop could boot "normally" also,

but still only with multicoloured vertical lines on the internal LCD

screen. The "normal" boot was observed by hearing the Vista startup

tune.

Problem Identification: So - this was most likely a graphics card

problem.:o

Solution: I had heard somewhere that a similar problem was solved by

"heating the chip". Unfortunately without any procedure details (hair

dryer, lamp, oven, or .. ? ). But since I was almost sure that I

had a graphics card problem, I would like to give this approach a shot,

before buying a new card. So... how to heat: I figured that booting

withoutout cooling the graphics card would definitely heat it up. So

this is what I did and it worked:

- I demounted the cooling devide from the graphics card

- then tried to boot ... but the computer shut down after a few

seconds (probably a chip overheating sucurity ?) The graphics chip

really got hot !

- I did this boot 2-3 times, always with the shut-down as result.

- on 4th attempt something different happened ... it did shut down

again, but this time the "Acer" sign appeared on the screen !.

Connection made !

- Then I re-installed the cooling devide on the graphics chip and

booted ... voila ... laptop booted normally, and has done since.

Comments:

- don't use this procedure if you are not willing to risk destroying

your graphics card completely, since I guess this could happen when

demounting the cooling device. But if you have identified the graphics

card as the bad component, there is not much to waste.

- Since the dust mat in the fan outlet caused the problem, I have now

a routine to clean this ever 3 months or so. Doing this, I hope a

similar problem will never occur again.