rasz_pl wrote on 2023-12-07, 08:42:
it looks to be keyed for your board with ET4000, OPs board has S3 805.
This truly confuses me as the listing says it's pulled from a system with S3 graphics but yeah, on closer inspection it is keyed identically to the Tseng upgrade and definitely not what I saw in the photo of the OP's motherboard. How annoying!
My newer board uses 2x 34 pin connectors for an extra 1MB and there's a Dell 486 with an ATI Mach 32 chip that uses the exact same looking memory upgrade board yet it's keyed differently yet again. Not wasting money on it to possibly fry my board experimenting.
rasz_pl wrote on 2023-12-07, 08:42:
Did you happen to stumble upon any data on Dell PowerLine 450DE/2 DGX Graphics Workstation (also called JAWS) system while doing research by any chance?
Ha yes I did but barely. You've found much more info than I did. I could only find some user manual for the motherboard and noticed it had an EISA riser in a very perplexing mount yet it used the same cache card the Optiplex (later board type does).
sirlemonhead wrote on 2023-12-07, 12:25:
Doe anyone have a list of the replacement cap values?
Seeing as I just did this job last week, yes.
This is for the older board revision I've mentioned before. Mine has Tseng video although looking at the photo of the OP's board, they otherwise look identical. Note: the newer board with a different layout has completely different capacitor values.
All capacitors are 4mm SMD electrolytics (sometimes referred to as size B)
10u 16V - x10
22u 16V - x6
3.3u 50V - x17
If you want detailed photos of sections of the board so you know where they go exactly, PM me and I'll send them. No use clogging up this thread unless everyone wants them.
mr_noun wrote on 2023-12-07, 14:12:
I appreciate the warning about the caps. I'll do a good visual inspection today when I install the sound card, but will have to address this regardless.
For my board and bios revision (A03 I think?) I was able to stick in a Western Digital 40 GB IDE drive. The bios wouldn't autodetect it but when I tried the option for the biggest drive (I think 504 mb) it read and I was able to install a DOS partition. So now I have 527 mb of total disk space, works for me.
** While we're all here, do you know anything about the power supply? I have a Lite On PA-4151 D 146 watt supply installed. I think it might be on the fritz as it doesn't always spin up my hard drive in time at boot. Would a standard AT supply work here? Or is there more Dell proprietary nonsense? I hope it's the former! **
Seriously, the newer board looked immaculate with no leaking caps or funny smell but probably 75% had leaked but not enough to become visible.
Interesting that you could use a big HDD. On both my boards with later BIOS revisions, I get an annoying "Hard Disk Controller Failure" every boot after about a minute of it hanging without an overlay or XT-IDE.
Mercifully the power supply is standard. Mine was dead on arrival (why I got the system so cheap) and I didn't feel like attempting a repair on an unknown and dead 30 year old PSU. I opted for a standard cheap ATX power supply and used a cheap ATX-AT adapter. They come with spade connectors to connect to the physical power switch on the front. I replaced the PSU's fan with a Noctua one and now my cheapo PSU is no longer noisy. Just to note with those cheap adapter you'll be missing the -5V rail unless you add regulation yourself but you shouldn't have a problem with a computer of this era. This has caused no problems for me with a Sound Blaster, SCSI card and NIC in there.