D8B Video Doesn't Play Nice With MIDI

[Dreamsequence]

Gang:

Anyone seen a video screen like this before? It shows up when I power up the HDR and gets really aggravated with the transport running. The more I run the playback, especially Stop and Play, makes it progressively worse. The real corker is if I click on one of the pulldown boxes. Then the screen gets filled with horizontal scan lines as shown. When it reaches this point, I lose transport control and sometimes mouse control.

d8b video 1.jpg (Array KiB) Viewed 1171 times

The next screen is what happens if I click on the pulldown boxes after it is filled with hash; the screen clears in the area where the boxes were opened.

d8b video 2.jpg (Array KiB) Viewed 1171 times

For the record, this is a 300Mhz D8B, v5.1 with all plug-ins unlocked, 256M RAM, Apogee clock card, running (3) OPT-8 cards. The HDR is also running (3) OPT-8 cards and has the Large Hard Drive BIOS. Only the HDR Tape Out to the D8B Tape Return are connected right now. Coax cable from Apogee card out to word clock in BNC and terminated on the HDR.

For remedies, I have replaced the video card, pulled and cleaned the edge connectors on the network card and MIDI card and reinstalled, replaced the RAM, and even moved the RAM to the center DIMM slot. Checked the BIOS several times, to make sure the P-N-P page shows IRQ-10 set to Legacy ISA. One puzzling thing: the BIOS sheets say to set the Video Seek First to AGP, but the CPU uses the first PCI slot after the AGP slot. I have not tried to reinstall the O/S, because it feels like a setup or hardware issue.

By the way, this is a rebuild, so this is the first time it has been connected to an HDR. I'm out of ideas.

Thanks for reading.

Pat

[Old School]

Hi,
I know you said you changed the ram, but you also said this was a rebuild. Exactly what type of ram are you using? If its the wrong type and you change it for another stick of the wrong type things wouldn't get any better. Every time I have seen a video screen like this it was a ram problem. Just a thought.

Have a blessed day in Christ,
Mike W.

[Dreamsequence]

Mike:

That was my first thought. I am reasonably certain it's the same DRAM sticks I was using in the HDR's I've been rebuilding. I will triple-check what I'm using. I might try to take it back to 32Mb (or whatever was original). I also have another complete 300 Mhz late production d8b and CPU to A/B parts if necessary.

Do you think there's any chance the BIOS ROM chip is bad? I read here that it is the same chip as the HDR stock chip, because it uses the same motherboard, so i have several takeouts. I recall there's a section in the CMOS setup that has the addresses of the RAM shown, but I didn't change anything from the recommended settings.

The odd thing is it will run for an hour without a single scan line showing up, and long as nothing is connected to the MIDI card. Within a minute or two of turning on the HDR, the lines start appearing, always from the top of the screen. I also tried another HDR and an SDR, with the same results. The jumpers on the MIDI card are correct.

Thanks for the tip.

Pat

[Old School]

Hi,
The bios chip has to be the same, as I have used a motherboard from an HDR to repair one of my D8B's. Just remember to use the correct size HD for whatever chip you might have. Hope you get it sorted out.

Have a blessed day in Christ,
Mike W.

[arjepsen]

Maybe try a different screen? In my experience older flat screens sometimes have electrolytic caps that go bad, and create graphic clitches.
Also try a different vga cable.

[Dreamsequence]

Thank you both. I'll try it all. I also have an ancient copy of both CheckIt and Sleuth on floppy. They go into the system at a low level and will check RAM, IRQ use, etc. as a last resort.

[Dreamsequence]

DUH!!!

What is it, Occam's Razor? "The simplest explanation is usually the right one". All this grief was the MIDI card. I pulled one from an HDR, and away we go...

Thanks for the help, gents!

Pat