I could be wrong but is your PRAM battery in backwards?
-
Hello MLAers! We've re-enabled auto-approval for accounts. If you are still waiting on account approval, please check this thread for more information.
Quadra 700 issue
- Thread starter marmotta
- Start date
i am wondering if the onboard vram has gone bad... I think your best bet is try to hit ebay and follow what an other had mentioned, Try a Nubus Video card. you should be able to pick one up for decent low price. The picture you posted is ok, but the quality is not good enough where i can tell if there are legs of I/C's that are bent over or touching. I wonder if mike Techknight wants to throw in his feedback?
This picture have best quality: http://discoremoto.cheapnet.it/apmarmotta/IMG_3327.jpg
The board is cleaned
Just use warm water and a gentle brush. I find paint brushes work really well. Shake water off and use compressed air or hairdryer to move water out from under chips. Then dry in an oven at 120 degrees F. Too hot is bad. Occasionally pull form oven and shake to get water out.
This is a great inexpensive method that I have used many, many times.
This is a great inexpensive method that I have used many, many times.
You need a VRAM testing program, I wonder if one of the common diagnostic softwares out there could test it. Because the issue could be int he VRAM, but it could also be in the RAMDAC.
Also those 3 caps being bad, highly unlikely, what meter?
Also those 3 caps being bad, highly unlikely, what meter?
With tester in continuity (ohm) good capacitor load and release energy, tester show a variable numbers. With this three bad capacitors my tester show only a fixed value of "0" or "0,15".
And my problems with powerswich is a confirmation (is not certainly vram related)
Depends on the circuit those caps are in.
Yes tantalum capacitors short, BUT.. you need to remove them to double verify.
Yes tantalum capacitors short, BUT.. you need to remove them to double verify.
You are right... I have removed the caps from the PCB and now is not in short. In any case I order a new caps.
The fact that moving the mouse left that artifacting is a clear indication it's a digital issue.
Tantalums have two failure modes. Dead short or blown up. They don't gracefully drift out of spec and when they die they make it pretty obvious as you have discovered.
Keep all your VRAM pulled as you mentioned that it's happening with it removed. This narrows the fault down to bad onboard VRAM or a problem with the video chipset. If you can, find a copy of Snooper and run the VRAM test.
Last edited by a moderator:
Similar threads
