> Today somehow I got it to show something better at boot… and then returned like that… hmmmm
That is typical behavior for a bad soldering joint.

The two Siemens chips next to the Cirrus chip are your video RAM. Try to push on the Cirrus and Siemens chips while the game is playing.

Elia1995 wrote:

No, I've never unplugged the MIDI cable from the sound card at all.

Yes, but what about the other end of the MIDI cable? Did you hot-swap that while the system was on?
That seems like the most likely cause for this, even if it didn't damage the sound card.
Either that or it's just a coincidence.

If the MIDI equipment is implemented correctly it has an optocoupler on the 'IN' side - thus it makes no difference wether the system is on or off when plugging.

xjas wrote:

You didn't "hot plug" the MIDI connector did you? (Plug or unplug it while the system is on.) That thing carries a nontrivial voltage - it's vaguely possible that a power spike could have done some damage, but 99.9% of the time this would be to some component on the sound card or keyboard. Actually I'm hard-pressed to imagine that could take out a Vram chip, but you never know.

Don't MIDI cables contain opto insolators ? Besides, MIDI is using a serial connection. Serial transmitters often contain diodes as reverse current protection (to prevent ESD, Electrostatic Discharge).

h-a-l-9000 wrote:

In DOS the VGA card doesn't use interrupts - except for one or two demoscene products. The corruption on the screen is not IRQ related.

True, I'm aware of that (EGA was hardwired to IRQ2 or used INT 0AH, though). I just mentioned it because this was the only logical reason I could think of.
I never thought the sheer presence of a mpu401 could cause a vram defect on a graphics card..

On the other side, I mean, this PC is so wicked, anything could be the cause.. 😀

@Elia1995 May I ask you again wheter this PC is located near a window ? If so, try movin' it to another place. 😁
Just kidding! Does the problem persists if you remove the entire soundcard ?

Edit: Some corrections, sorry.

Yes, removing the sound card doesn't help, apparently…
But still if I managed to get it look ALMOST normal this morning, it must be some soldering ?
It didn't have fuzzed graphic… it just started to type some GIBBERISH between normal text on boot up this morning, like for example

Starting Caldera DR DOS

Found 1 Device (now I don't remember what CTCM says)
Sound Blaster 16 PNP
GF#^ <£P £$ D FC
FH F

SET BLASTER=A220 I7 FFS $$ &

And so on, gibberish only at graphic level though because it actually does the things correctly

The cause could be anything then.
Heat related problems, cold soldering joints, defective RAM,VRAM or maybe aging BIOS chips..
Or a broken PSU.

Do you know of any place where you can get this PC checked ?
Fixing stuff like this isn't easy over the internet.

If you cant find a person or a place, make yourself a check list and try it yourself:
The best thing is to remove all parts and then adding them back step-by-setp until the problem occurs.
You can also use your mobile's camera to document every step you do. This makes re-assembling a lot easier.

I'll eventually try to bring it to my favorite local PC store for a quick check, maybe they can diagnose the problem better than me…… I just hope they still remember something of the hardware of the 90s…

Good luck! But please ask how much this will cost before you bring it to the store.
Sometimes they charge a hefty sum for doing nothing - they just put it in the back room for three days and claim they did everything they could.
Of course, not every store is like that. But in PC business it was common for a long time to fleece a customer. 🙁

I've always checked the issues along with the guys there 😒

Don't they work with you there in your place ?

Um, i was speaking in general. Some stores i know of are quite okay (and pricey, 80€ for a plain windows installation), but I've also seen sneaky/less friendly ones.
For example, I think it was In erarly 2000, I came into a store and asked if they had a PCI graphics card for my Socket 7 machine..
The man at the counter answered: "We don't have that." Then I asked: "Okay, where can I get that ?" He then said in a grumpy voice:"Dunno. Look at the junk yard."
Can you believe it ? He sent me to the junk yard! 😳
My, there are people out there..

L O L (with spaces to avoid the emoticon) seriously ???
So far the guy at my local computer store always just said that he doesn't have vintage hardware (I was looking for a 14-pin VGA cable for that exact PC before finding an "adapter" at home), but he never told me to look at the junk yard or something like that 😳

Seriously. 🙁

I throw old PCs out when they die. Finding a repair shop, paying for repairs and so on is not worth it. OEMs are still cheap on eBay so more economical / less hassle to simply replace a system.

Same exact thing with LaserDisc players.

Also: electronics repair by replacing components like chips or caps / soldering is highly exceptional nowadays. The norm is swapping out broken modular components like PCBs / PSUs.

Well, still I think that a Vesa Local Bus (VLB) ISA graphics card would instantly fix the issue...

the PC itself will say "What's that ? An integrated graphics chip with bad memory ? Screw it, lemme see if there's something in a Vesa bus... great, let's proceed 😎 "

One can always dream... It may be disabled by jumper on this board..

PeterLI wrote:

I throw old PCs out when they die. Finding a repair shop, paying for repairs and so on is not worth it. OEMs are still cheap on eBay so more economical / less hassle to simply replace a system.

Same exact thing with LaserDisc players.

Also: electronics repair by replacing components like chips or caps / soldering is highly exceptional nowadays. The norm is swapping out broken modular components like PCBs / PSUs.

That's understandable. But old PCs from Olivetti, Schneider, Tandy, Amstrad or Compaq [..] have something special on them.
They're both quirky and charming in some ways. Sometimes they are fascinating us because they are so different from an ordinary OEM PC.
Be it a custom mouse port, an unusal BIOS (like WinBIOS), a strange shape or floppies that draw their power from the floppy cable (Schneider AT).
And then there's also nostalgia, a strong force which plays tricks on our minds.. 😉

No way I'm gonna throw away this PC… after all it WORKS it's just the graphics that screwed up for now…

h-a-l-9000 wrote:

> Today somehow I got it to show something better at boot… and then returned like that… hmmmm
That is typical behavior for a bad soldering joint.

The two Siemens chips next to the Cirrus chip are your video RAM. Try to push on the Cirrus and Siemens chips while the game is playing.

Hmmm... apparently it did nothing... ?

Whew... it seems that buying a WORKING VLB GPU is much harder than I thought... I'm having difficulties to find a "working" one even on eBay...

It is. You could try to locate a fast ISA card instead, your system should work with it.

I'd first get some shitty 5euro isa vga just to make sure the pc is operating correctly with it. Then you can see what to do with a better card, if it's working and worth it.