8600 Video Issue

[LCARS]

Hi everyone. I'm having a very irritating problem with my stock 8600/300. I'm using the built-in video card (max VRAM & 128MB RAM) with OS 9. I've used both my AppleVision 1710 and 17" graphite CRT (using an Apple VGA to DB15), but the image comes in with thin vertical lines evenly spaced across the screen with two large vertical lines on either side of the mouse that move with it. The background (what can be seen of it) is in color but almost looks solarized. Even the composite out to a TV is line-ridden.

I looked at the mobo and contacts and everything is clean, in fact they look brand new. No rust, corrosion, bending, or dust. I even put in an ATI PCI card, but it was not recognized and all I got was a blank screen (it worked in my beige G3 OS 9.1). Does anyone have any ideas? :-/

 

[Unknown_K]

Remove the VRAM and check for dirt or corrosion, replace it if you have spares, if not put them back in in different order. If the problem looks different it could just be 1 bad VRAM. If the problem does not go away with new VRAM then you might have a bad video chip.

 

[LCARS]

Thanks for your reply. I'll see if that helps. The RAM holder plastic is looking a little frail. If it is a bad video chip, isn't it integrated onto the mobo in the 8600? Would that mean that the whole board is bad or just the graphics chip?

 

[beachycove]

Sounds like a vram problem to me, either in the dimm/simm/ whatever it is, or on the logic board.

The non-working pci card is a mystery, however. That should work. Could, I wonder, a problem with the vram somehow pre-empt the machine's use of the pci card? Have you tried starting up with two monitors attached?

 

[LCARS]

beachycove- No, I haven't tried with two monitors yet. I thought the PCI problem was mysterious, too. I would like to do a fresh install of 7 and 9, but I can't see the desktop well enough to do that. I wonder if the problem is software rather than hardware. I'll reseat all the chips again, but is there a hardware reset switch? I have yet to try a PRAM reset. Its been unplugged for about two months since the last time I tried to solve this problem.

 

[mac2geezer]

I don't have any fresh ideas about the lines using the internal VRAM. However, if you have VRAM installed and install a PCI video card the PCI card is a secondary monitor, so the 8600 boots to the internal VRAM and you see nothing because there's no monitor connected. You need a monitor connected to the internal port to swap monitors around via the monitors control panel. As per the previous suggestion, connect two monitors and proceed.

At least that's the way my 8600/300 behaves.

 

[Unknown_K]

I believe it boots to whichever video input has a monitor (or some kind of terminator) connected to it. I have an ATI video card in an 8500 and that is the screen it boots to, not the onboard video. If you have multiple monitors connected then it boots to the one you picked in the control panel.

 

[LCARS]

I'll put the PCI back in and plug in two monitors to see what happens. Its all a bit mysterious. I wonder if one or all of the VRAM modules is faulty. Ah, "antique" computers...never a dull moment.