Matrolisk wrote on 2024-03-26, 23:24:https://imgur.com/a/79gHNxl
The chips say - nec japan - 424400-70 9115FUO29
How many of those do you use at the moment?
You only use 30pin Simms now, is it correct?
With ATX PSU powering AT mobo the first thing that should be checked is the voltages. With no load on the 3V3 rail the PSU might not regulate 5V properly. The CX-M Corsairs should have DC-DC from 12V to 5V and 3V3 but I'm not sure if group regulated or independent. That's assuming nothing is wrong with the PSU.
If the 5V line is within 5% and there isn't excessive ripple or noise then perhaps the mobo has some damage on it which affects 5V delivery to the ISA slots - that would cause it to crash more often with more cards. Why it's doing it more in BIOS could be just a coincidence or the way the code is written.
CoffeeOne wrote on 2024-03-27, 18:58:Matrolisk wrote on 2024-03-26, 23:24:https://imgur.com/a/79gHNxl
The chips say - nec japan - 424400-70 9115FUO29How many of those do you use at the moment?
You only use 30pin Simms now, is it correct?
All 8 30pin slots are filled. The EDO ram is removed.
Horun wrote on 2024-03-27, 02:50:What ? An ISA video card on a 486 caused it to crash ? What exact ISA video card ? Sounds like the board has some major issues b […]
What ? An ISA video card on a 486 caused it to crash ? What exact ISA video card ?
Sounds like the board has some major issues because an ISA in a 486 should never cause a crash....
Also: what PSU are you using ? sounds like you are not loading the PSU enough (with just board, 486 cpu and video).
Most PSU require minimum of a few amps on the +5 and +12 to be stable.....hook up a few HD's just to molex to draw more
PSU is Corsair CX450M
Tried plugging in more drives on the molex connectors. Still crashes in BIOS setup.
CIRRUS LOGIC PT-521/3 ISA GPU
The computer worked with the card for a while then crashed....
Now every time I boot the computer with that card it displays some text and a flashing cursor but that's all
The ATI Mach 64 works fine other than the main issue of the bios setup crashing.
Matrolisk wrote on 2024-03-29, 00:02:All 8 30pin slots are filled. The EDO ram is removed. […]
CoffeeOne wrote on 2024-03-27, 18:58:Matrolisk wrote on 2024-03-26, 23:24:https://imgur.com/a/79gHNxl
The chips say - nec japan - 424400-70 9115FUO29How many of those do you use at the moment?
You only use 30pin Simms now, is it correct?All 8 30pin slots are filled. The EDO ram is removed.
Horun wrote on 2024-03-27, 02:50:What ? An ISA video card on a 486 caused it to crash ? What exact ISA video card ? Sounds like the board has some major issues b […]
What ? An ISA video card on a 486 caused it to crash ? What exact ISA video card ?
Sounds like the board has some major issues because an ISA in a 486 should never cause a crash....
Also: what PSU are you using ? sounds like you are not loading the PSU enough (with just board, 486 cpu and video).
Most PSU require minimum of a few amps on the +5 and +12 to be stable.....hook up a few HD's just to molex to draw morePSU is Corsair CX450M
Tried plugging in more drives on the molex connectors. Still crashes in BIOS setup.CIRRUS LOGIC PT-521/3 ISA GPU
The computer worked with the card for a while then crashed....
Now every time I boot the computer with that card it displays some text and a flashing cursor but that's all
The ATI Mach 64 works fine other than the main issue of the bios setup crashing.
As a minor point, I would just test with the minimum of RAM for basic stability tests.
So remove 4 Simms (so with 4 MB only) and repeat the tests. If the behaviour changes in anyway (less crashes, more crashes), then my bet is the RAM.
Yes, and measure the 5 volts line when the computer is turned on. A simple volt-meter can do that.
Last but not least, check the CPU. Am5x86 is one of the most advanced cpus around. Maybe you are running it with 5 volts, then it would crash even with very good cooling.
How is it running now? 4 times 33?
Do you have another cpu to test. Best would be a intel DX33 or an Intel DX2-66, both are 5 volts cpus and the most compatible cpus for a 486 system.
The computer runs fine for normal use, have not experienced any crashes in that regard. (Sorry if anyone misunderstood that.)
Checked the 5v output and it was 5v +- .03 about.
I don't have any other cpus to test on this board at the moment but the current one has been lowered to 100mhz with jumpers.
Removed all but one stick of ram with no change.
I tried using a different psu, an older one that I had with no change.
The ISA card worked fine while using it, then weirdly worked fine when I switched back to the newer psu.
The computer still always crashes when try to go into the bios setup. All that changes is how fast the crash occurs.
Sometimes the setup doesn't even load others I get about 10-30 seconds before the crash happens.
Matrolisk wrote on 2024-03-31, 04:01:.....
Removed all but one stick of ram with no change.
.....
That does not work. You need 4 sticks of 30pin RAM always for a 486.
Tried it with just 4 sticks of ram.
The BIOS setup crashed when loading.
Everything else seemed to work fine.
Matrolisk wrote on 2024-04-07, 03:42:Tried it with just 4 sticks of ram.
The BIOS setup crashed when loading.Everything else seemed to work fine.
We still know little about this system.
"Everything else seemed to work fine."
Can you give some examples? What seemed to work fine?
Can you run both Quake and Doom from Philisbenchmark suite?
Not sure if 4 MB of RAM is enough, maybe you need the full 8MB.
No pictures needed, just describe what you see. So for this test a minimal system is needed: mainboard, cpu (with cooler), RAM, graphics card, harddisk.
No sound card or other stuff needed, we just want to know if Quake and Doom run in principle without sound.
The picture you posted before:
https://imgbb.com/r65QQZB
that shows your board, is it correct?
What is strange that the transistor is missing near the CMOS battery (which is shown on the Retroweb picture)
I haven't managed to get any hardrive to work with the system yet.
The on-board connector seems to be for the old style 40wire cable and the harddrive the I plugged into it wouldn't work.
I bought an isa ide controller card with a harddrive and floppy connector but only the floppy drive works. Tried multiple known working drives and none of them worked.
I think it may be a settings issue but I don't know how to change drive settings outside of the bios setup.
So I can't run the above mentioned tests as they need to be put on a harddrive to run.
What I've been running are old disk only games from 80's and early 90's.
I doubt they a very demanding.
I was fiddling around to try and figure out more and discovered something.
I reset the cmos and when the computer booted up the keyboard wouldn't respond to hit F1
Earlier when the computer stopped responding I thought I was a crash. But in this instance I noticed the cursor was still flashing.
However the keyboard was not working at all....not even the lights (hitting caps did not make the light come on.