PDA

View Full Version : Powerbook G4 - Blue Artifacts on Screen




zdobson
Apr 19, 2011, 05:17 AM
I have a 15" PBG4 1.25ghz and am having some screen artifacts show up. Everything is running fine otherwise. I haven't used this machine at all in months and I'm trying to clean it up to sell it. Any info would be helpful.

http://www.zachdobson.com/temp/screen1.png



bizzle
Apr 19, 2011, 05:42 AM
Bad GPU son.

Nameci
Apr 19, 2011, 07:06 AM
Try to connect an external monitor and see if it also displays the same. If it is then it is GPU, if it is not then it could be the LVDS connector or the LVDS cable.

iMacC2D
Apr 19, 2011, 09:27 AM
The fact that the artifacts have appeared in the screenshot is a good indication that the LCD is not at fault. It's most certainly a defective GPU. Not much that can be done with it now, ignoring the fact that logic boards are expensive, i'd doubt that Apple would even stock parts for them anymore.

zdobson
Apr 19, 2011, 09:43 AM
I'll try the suggestion of hooking up a monitor first. I'm currently formatting the HD to remove personal info, so I'll have to wait until after that.

What should I do with this machine? Should I replace the logic board? I found a used one for $100 on eBay (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120709976056#ht_1480wt_931). I'm planning to buy a new MBP and would like to get any money I can out of this.

zdobson
Apr 19, 2011, 12:44 PM
Now this is looking different. I'm not sure why this would have changed. The finder windows are clear.

http://www.zachdobson.com/temp/screen2.png

Also, the CPU keeps running between 30-90% even though there are no applications running (other than activity monitor). Related or no?

Nameci
Apr 19, 2011, 01:18 PM
If I were you i would try to strip memory, or reseat memory on the slot.

zdobson
Apr 19, 2011, 01:58 PM
If I were you i would try to strip memory, or reseat memory on the slot.

Pulled both out and switched them. No change.

Nameci
Apr 19, 2011, 03:54 PM
Have you tried to use an external monitor, that would tell you if your gfx chip is bad.

zdobson
Apr 19, 2011, 05:53 PM
Have you tried to use an external monitor, that would tell you if your gfx chip is bad.

Yes, external monitor looked like the second photo. Now everything is back looking like the first photo.

Nameci
Apr 19, 2011, 06:06 PM
for sure you have a faulty gfx chip. Your best bet is to replace the logic board.

adcx64
Apr 20, 2011, 07:45 AM
Maybe the GPU just needs to be reflowed?

chrismacguy
Apr 20, 2011, 08:01 AM
Maybe the GPU just needs to be reflowed?

That wasn't an issue on that series of powerbooks. Also, I wouldn't recommend attempting a reflow.. a new logic board is much easier, especially since I dont think it is a reflow issue - since the gfx is working but corrupted.

Nameci
Apr 20, 2011, 08:07 AM
Seems to me that it is caused by a faulty video memory...

zen.state
Apr 20, 2011, 08:23 AM
Seems to me that it is caused by a faulty video memory...

This is my guess also. I think if it was the GPU the video would be far worse or maybe not even work at all. Since the PowerBooks have dedicated video memory this can't be fixed with new system RAM as you wondered earlier in the thread.

Best solution would be a new logic board.