7500 half-way booting

[coius]

Ok, i am just scratching my head on this one. I pulled out my PM7500/100 with G3 upgrade and tried to get it working.

It chimes and comes up to the grey screen, but refuses to boot any further. I have tried with different CPU Cards (G3/604/601 (original)), different configs of ram. with NOTHING attached (No drives, no keyboards, no floppy), and with different drive setups. I have tried with and without PCI Cards, as well as put a fresh PRAM battery in. I have zapped the PRAM (and power manager on-board button) and whatnot.

has anyone had this happen? I have tried with terminated SCSI, with no SCSI Device on it.

I can't seem to get it to display to the Radeon 7000 32MB PCI Card in it, but it WILL display to internal video. There is no cache Chip in it. I am not sure what I am missing...

I normally am good with this stuff, but I am a bit rusty as I haven't dealt with old-world machines much lately. hence the reason for me getting a (now defunct)9500 and 7500

 

[coius]

oh, also when it gets to that screen, it doesn't boot from any device. I can put in a floppy without a system on it, and it won't even eject it

 

[MacJunky]

Will it work from cold boot(no power then turned on) but not from warm boot(reset, no power cut).

If so I have a 7300/200 with the exact same issues as you have right down from the grey screen to the PCI gfx not working but onboard being functional.

 

[coius]

it won't boot past that at all. I can try cold boot, or warm boot. doesn't seem to get past it. I let it sit over the last 2 hours and it did nothing. No disk access or anything.

 

[tmtomh]

I've experienced a variation on this sort of behavior with similar PCI Power Macs (a 7300, and a 7600/8600 frankentosh).

The only thing that worked was a total motherboard reset (IIRC disconnect everything from the mobo including drive cables, PRAM battery, and PSU cable; then press the front power button once), followed by letting the motherboard sit with nothing at all connected to it for several days.

Sounds like voodoo I know, but when I hooked it all back up, it worked fine in both cases.

My only guess is that the computer gets "confused" - RAM can enter an error state even if it's actually fine; the PMU/CUDA can crash; and a number of other things can happen, that apparently can be solved only by letting the darn thing sit (which I presume drains all the capacitors on the mobo or something like that).

M

 

[coius]

Ok, i will dig it out later today and do that. Thanks for letting me know. I never would have thought of that!

 

[Temetka]

CUDA?

 

[coius]

Wow! it works!!! thanks for the tip SO MUCH!!! I am currently booting into Mac OS 8. It seems that the built-in video is shot though :-/ Although it boots with the Radeon 7000, it seems to put out nothing but garbage onto the internal video's screen when the monitor is hooked up.

 

[Quadraman]

Did you try getting a video signal through the built in video with the Radeon unplugged? I find it surprising that it worked before you did your experiment and now it doesn't.

 

[coius]

yeah, i tried it without the radeon. That's the only way I could get video out on the monitor. It just put out lines down the screen and characters on the screen. It's not the monitor, because it works on the 7200. So I believe something on the board is fried. There are no extra VRAM DIMMs, so it can't be that. I am guessing that the onboard VRAM is fried

 

[Quadraman]

yeah, i tried it without the radeon. That's the only way I could get video out on the monitor. It just put out lines down the screen and characters on the screen. It's not the monitor, because it works on the 7200. So I believe something on the board is fried. There are no extra VRAM DIMMs, so it can't be that. I am guessing that the onboard VRAM is fried

According to all the links I tried for more info on the 7500, there are 4 VRAM slots on the motherboard and each takes up to 1mb with 4mb being the maximum total VRAM so I don't think there is any VRAM onboard. It all gets installed in the slots. If your VRAM slots are empty, that may be your problem.

http://www.everymac.com/systems/apple/powermac/stats/powermac_7500_100.html

See for yourself.

Here's a picture with labels

http://www.mathdittos2.com/images/010722-02-010labeled.jpg

 

[tmtomh]

Wow! it works!!! thanks for the tip SO MUCH!!! I am currently booting into Mac OS 8. It seems that the built-in video is shot though :-/ Although it boots with the Radeon 7000, it seems to put out nothing but garbage onto the internal video's screen when the monitor is hooked up.

Just for clarification, which tip did the trick for you?

 

[coius]

According to all the links I tried for more info on the 7500, there are 4 VRAM slots on the motherboard and each takes up to 1mb with 4mb being the maximum total VRAM so I don't think there is any VRAM onboard. It all gets installed in the slots. If your VRAM slots are empty, that may be your problem.

Worked fine before. actually, I figured out what the problem was. The monitor seems to be FUBAR. I tried another monitor on it, and now it works (albeit @ 640x480). there are no VRAM Slots occupied. So it has SOME Vram in it. Just only 1MB. I am guessing it shares with main memory though with no VRAM in it.

One reason I noticed, is that I have 256MB of memory in the machine, but it only reports 255MB, but when I use the Radeon, it says 256MB again. I am guessing it only uses external memory when it's in the slots.

Failing that theory, it might be that you can only use 2x 1MB and 2x 512KB Sticks. which would make up for the extra 1MB to make 4.

Heck, i really don't know how it's designed, but I wouldn't be surprised that it would be using Shared VRAM

 

[paws]

Coius -

The garbled output you were getting on the internal video, what did it look like? Just random colours? Could you see the cursor? My 7300 is being difficult

 

[coius]

oh hey! sorry for not replying. I figured it out. It doesn't have VRAM. I never really paid attention. I found that I put the VRAM in my 7200 to boost that, and I didn't realize the 7500 didn't shit with VRAM.

What it did was show a gray screen that has a solid red line running from the top to the bottom of the monitor. When I moved the mouse, it would move the vertical line across the screen. I am guessing since it didn't have VRAM, it probably couldn't do much more than the cache that the GPU had in it.

It's fixed now, but if you are having anything with that happening, get some VRAM Sticks. I don't remember how much I have... It's only 2 DIMM sticks (it's smaller than regular RAM, like by half the length)

Not sure how many NanoSeconds it needs to be. If you have to, try MacTracker. It should say how fast the RAM needs to be...