Looking at two similar risers the big caps on both are definitely marked 10uf 16v, the small ones marked 103Z which should be 0.01uf (which generally do not fail/short if ceramic but will if Tantalum)
You can use any Electrolytic 10uF 16v for the big ones as they are only for filtering noise off the voltage planes.

i dont think thats the way to check if the caps are ok. to check the capacitance you should remove at least one leg from the board and measure it out of circuit.

i dont fully understand why it should have anything to do with dma anyway.

I have a prolinea 5120 and i believe you can do some settings within the setup or diagnostics utility regarding expanion cards maybe dig into those settings.

Joakim wrote on 2024-11-10, 19:44:

i dont think thats the way to check if the caps are ok. to check the capacitance you should remove at least one leg from the board and measure it out of circuit.

i dont fully understand why it should have anything to do with dma anyway.

I have a prolinea 5120 and i believe you can do some settings within the setup or diagnostics utility regarding expanion cards maybe dig into those settings.

Well... I tried 2 different versions of the diagnostic utility and none of them had that kind of settings. All I have is disk, ports (com & lpt), date, input (num lock), video and power management.

Yours is a Pentium while mine's a 486...

Boy was I wrong!!

Turns out, no serial ports are working as well! Base ports and Serial ports have the same behaviour: any connected device gets detected, but nothing actually works (sound card, serial mouse, mt32pi on serial port). But PS2 keyboard and mouse do work (thank god).

After removing the HDD, I saw a resistor was chipped away (C71)... It can't be just that!?!

nice! it's certainly possible...

but at second glance, what is that chip next to it? some kind of memory? vram?

Joakim wrote on 2024-11-11, 17:49:

nice! it's certainly possible...

but at second glance, what is that chip next to it? some kind of memory? vram?

The board has 4MB of onboard memory... These chips awfully look like RAM chips. Top it off with the fact that it's right next to ram slots...

It looks as if the capacitor is linked to these presumably ram chips... Memory passed all tests. 😒

I see, I was not aware that some desktop computers had built in memory. did replacing this capacitor alleviate the issue you were having?

I am 99.99% sure I found the problem. After pulling the board out, I saw a full burnt trace. This trace goes to the riser slot...

It's so close to other traces and goes for such a long distance... I think the only option is to solder a wire between the vias. Scary stuff for an amateur like me...

that dark line was a trace? 😃

sounds easy enough. just need the right size of wire. practice on something else if you feel uncomfortable.

you can do it! for science and bad poetry!

Think it's time for me to move away from my Aliexpress soldering kit... Any recommendations on a good enough soldering station and the type of wire to perform this repair?

1 Trace what this track carries and where its going. Might shed some light on the cause.
2 Cheap good soldering solutions were dominated by cloned Hakko T12 cartridge soldering irons for the last ~10 years. Nowadays Chinese moved to something even better - cloned JBC C210 / C245 irons. $40 ($90 with all the tips and 100W USB-C charger) Fnirsi HS-02A will deliver $600-1000 worth of soldering performance https://www.fnirsi.com/products/hs-02?variant=45192934818010 Whats more important than the iron is skill/practice, right tip for the job (means none of that I-type sharp needle garbage) and flux.

I gave it a shot and replaced the trace with a 28 awg wire I had laying around. I took a chance by doing so and assumed that what might have shorted was either an ISA card or the riser itself. WELL I WAS WRONG!

Right as I connected the power cord into the PSU, the resistor at the end of the trace bursted into flame! As you can see at C109, it is now cracked opened... Was it faulty in the first place or is there a bigger underlying problem?

That's a tantalum capacitor, which apparently has shorted. It is quite possible there are others like it... fireworks potential is significant until all of them get replaced.

Yeah... I got to the same conclusion. But the ratings are puzzling me: 106 20Y. What does "20Y" actually mean on these old caps?

10 * 10^6 = 10µF, 20Y should be 20V and Y some sort of tolerance or temperature rating. 226 would be 22µF for example.

Here are the latest news on my Prolinea 4/50... I thought I had everything in order for a miracle, but the miracle didn't show up! Here's what I fixed:

1. Replaced the PSU with a more recent one (yes, it has -5V)
2. Fixed the burnt trace as shown previously (worked so much, that the smt cap at the end blew up)
3. Replaced the smt cap (confirmed I had continuity from the start of the trace to the end of the cap)
4. Replaced some caps on the riser I could not get a reading on my multimeter (turns out my multimeter is just too weak to get a reading).

Result 1: smoke test passed!
Result 2: the sound card (Audician 32plus) on the riser gets properly detected with both Unisound and SetupSA... I no longer get errors in SetupSA where it use to complain about ports and SB not being detected. However, not a single sound gets out of it! Totally mute (games and SetupSA tests)!

What else could be wrong!?

is +12V reaching the card ? If it is missing the analog side won't get power and no sound can come out the chip. Alternatively, if the line/speaker out jumpers are missing, there also won't be any sound.

Tiido wrote on 2024-12-02, 18:08:

is +12V reaching the card ? If it is missing the analog side won't get power and no sound can come out the chip. Alternatively, if the line/speaker out jumpers are missing, there also won't be any sound.

I've eliminated problems coming from the card itself... Tested in another system and worked right off the bat. Also, mixer was at full blast, just to be sure...

Soooo yeah, it could be another power problem... Is this a typical behaviour to have an ISA card being detected and receive signals but not having the power to do its thing?

I wish I could get my hands on a wiring diagram for that riser slot...

If the riser board isn't having 12V on it, the card isn't going to output anything even if it does work in another system. You can see ISA pinout here and can verify that all the voltages are present : https://en.wikipedia.org/wiki/File:ISA_Bus_pins.png

5V is definitely present or the card wouldn't be doing anything at all, but it will need 12V to power its analog stages and lack of sound output points to the likelyhood that 12V is missing.