eisapc wrote on 2026-05-12, 08:03:

Picked up a Zenith Data Systems ZF-148 8088 PC from the basement. Had to search for a matching XT keyboard and RGB/RCA monitor […]
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Picked up a Zenith Data Systems ZF-148 8088 PC from the basement.
Had to search for a matching XT keyboard and RGB/RCA monitor for a while.
The system was not powering on, but after replacement of the shorted tantals the system powered up and booted from FDD at least.
Unfortunately the HDD seems dead and after a few minutes the RIFA inside the PS released its magic smoke.
Replaced the RIFAs as well. Will have a closer look at the HDD which is actually 3,5" MFM drive mounted on hardcard with full lenght controller board.

Is the hard card Zenith branded by any chance? In 1989 3.2 BIOS there is a separate section for old style XT MFM controller they call "Tempest". They detect its presence by checking for ZD signature in HDD Bios stored at C81Bh https://github.com/raszpl/Zenith_ZBIOS/blob/m … 03.2C.lst#L5027

1seg000:1840 MFM_Tempest_detect_presence proc near
2  mov     cs:MFM_Tempest_controller, 0
3  push    ds
4  push    ax
5  mov     ax, 0C800h      ; C800h address of MFM ROM
6  mov     ds, ax
7  assume ds:nothing
8  cmp     word ptr ds:1Bh, 'DZ' ; Check for Zenith Data Systems "ZD" signature
9  jnz     short end
10  mov     cs:MFM_Tempest_controller, 0FFh
11end:
12  pop     ax
13  pop     ds
14  assume ds:nothing
15  retn
16MFM_Tempest_detect_presence endp

No, the hardcard is not original. I remember adding it myself some years ago, when it was still working like a charm.

Stripped my K7S8X of it's VRM FETs and all major caps - replacement coming in on monday probably.

tehsiggi wrote on 2026-05-12, 10:49:

Stripped my K7S8X of it's VRM FETs and all major caps - replacement coming in on monday probably.

The attachment vrm_gone.jpeg is no longer available

The attachment caps_gone.jpeg is no longer available

Curious, your K7S8X looks completely different from mine:
Save or recycle hardware.

bofh.fromhell wrote on 2026-05-12, 20:32:

Curious, your K7S8X looks completely different from mine: Save or recycle hardware. https://i.imgur.com/AValQa8m.jpg […]
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tehsiggi wrote on 2026-05-12, 10:49:

Stripped my K7S8X of it's VRM FETs and all major caps - replacement coming in on monday probably.

The attachment vrm_gone.jpeg is no longer available

The attachment caps_gone.jpeg is no longer available

Curious, your K7S8X looks completely different from mine:
Save or recycle hardware.

Mine is the Rev 1.02 - yours is Rev 3.0 - I had the latter back in the day in my system. But for whatever reason I only found the Rev 1.02 laying around, which is fine as well.

Recently I picked up a small haul from the flea market. A socket 7 motherboard with 686 Cyrix and some RAM. Visually looks ok but can't test it at the moment. The other stuff was three graphics cards. Two GeForce 2 MX 400 and a Virge....

I didn't have high hopes for this lot since it was jumbled all together and probably damaged but... today I finally got around to test it. The Gainward and TNC GeForce cards worked flawlessly... and for the Virge from ColorExpert I had to get another, older system, because of the voltage standard on PCI slots. I took out my Compaq Pentium 2 machine... and plugged in the card.

The Virge was.... also working, as good as a Virge can. It was a 4 MB model and I didn't one in my collection so I picked it up to play around with. With Finalreality it suffered through, but it got through. Just for fun I tried to run 3Dmark 99 and that was just too much... 3 fps in first bench scene and 0 in second...

It was still fun to test these out and I was quite happy that they all worked 😀

tehsiggi wrote on 2026-05-12, 20:37:

Mine is the Rev 1.02 - yours is Rev 3.0 - I had the latter back in the day in my system. But for whatever reason I only found the Rev 1.02 laying around, which is fine as well.

Aha.
Still, weird that they kept the model name through such massive changes =)

bofh.fromhell wrote on 2026-05-12, 20:47:

tehsiggi wrote on 2026-05-12, 20:37:

Mine is the Rev 1.02 - yours is Rev 3.0 - I had the latter back in the day in my system. But for whatever reason I only found the Rev 1.02 laying around, which is fine as well.

Aha.
Still, weird that they kept the model name through such massive changes =)

Because technically it's still the same board. Same set of features, same chipset etc. So it's really just a revision

Shader_BiH wrote on 2026-05-12, 20:46:

Recently I picked up a small haul from the flea market.

I saw a local online auction with these 4 items recently! What flea market they had arrived to so fast? 😮

GigAHerZ wrote on 2026-05-13, 11:58:

Shader_BiH wrote on 2026-05-12, 20:46:

Recently I picked up a small haul from the flea market.

I saw a local online auction with these 4 items recently! What flea market they had arrived to so fast? 😮

I picked them up at my local market in Zenica. It's always open on Wednesdays and Saturdays. Now there is possibility that these people picked them up abroad to sell here. They do get most of their stuff like that, either for very low price or even for free as far as I know.

tehsiggi wrote on 2026-05-12, 20:55:

bofh.fromhell wrote on 2026-05-12, 20:47:

tehsiggi wrote on 2026-05-12, 20:37:

Mine is the Rev 1.02 - yours is Rev 3.0 - I had the latter back in the day in my system. But for whatever reason I only found the Rev 1.02 laying around, which is fine as well.

Aha.
Still, weird that they kept the model name through such massive changes =)

Because technically it's still the same board. Same set of features, same chipset etc. So it's really just a revision

Biggest visual difference is obviously the migration of connectors to a more sensical and modern location/orientation along the edge of the board.

ubiq wrote on 2026-05-13, 13:39:

tehsiggi wrote on 2026-05-12, 20:55:

bofh.fromhell wrote on 2026-05-12, 20:47:

Aha.
Still, weird that they kept the model name through such massive changes =)

Because technically it's still the same board. Same set of features, same chipset etc. So it's really just a revision

Biggest visual difference is obviously the migration of connectors to a more sensical and modern location/orientation along the edge of the board.

Not only that, the new revision is smaller and they removed a PCI slot as well.
ASRock also lists them separately:
https://www.asrock.com/mb/sis/k7s8x/
https://www.asrock.com/mb/SiS/K7S8X%20R3.0/index.asp

The older revision basically is the K7S8XE without IEEE1934 and the 746FX chipset instead of 748

Re-cap in progress.. caps arrived earlier than anticipated.

Shader_BiH wrote on 2026-05-13, 12:02:

GigAHerZ wrote on 2026-05-13, 11:58:

Shader_BiH wrote on 2026-05-12, 20:46:

Recently I picked up a small haul from the flea market.

I saw a local online auction with these 4 items recently! What flea market they had arrived to so fast? 😮

I picked them up at my local market in Zenica. It's always open on Wednesdays and Saturdays. Now there is possibility that these people picked them up abroad to sell here. They do get most of their stuff like that, either for very low price or even for free as far as I know.

Woah! Quite a journey!
Glad to see a Vogon owning these now!

So, the re-cap worked - the board is happy as can be. Bulged caps are gone, first quick test looks good.
The board even had 4 unpopulated spaces on the back behind the CPU socket, size being 1206. I put some 220µF 2,5V tantal polymers there as well, while I'm at it.

Caps used:

• VRM Input section: RPF1012152M006K
• VRM Output section: RR50E152MDN1
• Back of socket: T520A227M2R5ATE025
• Rest: RPF0809102M006K

MOSFETs: IPD090N03LGATMA1

Great work..

Glad you were able to revive the motherboard.

tehsiggi wrote on 2026-05-13, 19:47:

So, the re-cap worked - the board is happy as can be. Bulged caps are gone, first quick test looks good. The board even had 4 un […]
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So, the re-cap worked - the board is happy as can be. Bulged caps are gone, first quick test looks good.
The board even had 4 unpopulated spaces on the back behind the CPU socket, size being 1206. I put some 220µF 2,5V tantal polymers there as well, while I'm at it.

Caps used:

• VRM Input section: RPF1012152M006K
• VRM Output section: RR50E152MDN1
• Back of socket: T520A227M2R5ATE025
• Rest: RPF0809102M006K

MOSFETs: IPD090N03LGATMA1

The attachment board_running.jpg is no longer available

The attachment board_happy.jpg is no longer available

tehsiggi wrote on 2026-05-13, 19:47:

So, the re-cap worked - the board is happy as can be. Bulged caps are gone, first quick test looks good. The board even had 4 un […]
Show full quote

So, the re-cap worked - the board is happy as can be. Bulged caps are gone, first quick test looks good.
The board even had 4 unpopulated spaces on the back behind the CPU socket, size being 1206. I put some 220µF 2,5V tantal polymers there as well, while I'm at it.

Caps used:

• VRM Input section: RPF1012152M006K
• VRM Output section: RR50E152MDN1
• Back of socket: T520A227M2R5ATE025
• Rest: RPF0809102M006K

MOSFETs: IPD090N03LGATMA1

The attachment board_running.jpg is no longer available

The attachment board_happy.jpg is no longer available

Great work 😁 Always happy to see hardware restored. I also have few boards in need of cap change. I was wondering if it's better to try to find the same capacitors or as close to the original ones, or to go with more "modern" ones like you did? The boards I have are from cap plague era, so I was thinking that going for original spec might not be the best option.

I've been working on a local dial-up network to get my Palm III online. Not fully working yet, but the modems communicate and establish a stable connection.

The hardware is: Palm III, Palm modem, Cisco SPA112, Genius 56k modem, and a laptop running Xubuntu.

My next goal is to get an email client working on the Palm.

Angus.Young wrote on 2026-05-13, 22:46:

Great work..

Glad you were able to revive the motherboard.

They're nothing to write home about, but from my experience they've always been rock solid, despite their low-cost. Had one for years with an Athlon XP 2100 @ 2GHz and it served me well. Glad to have this one working well. Next is multiplier mod installation, Vmod for VCore and the AIO mount printing to get watercooling going.

Shader_BiH wrote on Yesterday, 00:33:

Great work 😁 Always happy to see hardware restored. I also have few boards in need of cap change. I was wondering if it's better to try to find the same capacitors or as close to the original ones, or to go with more "modern" ones like you did? The boards I have are from cap plague era, so I was thinking that going for original spec might not be the best option.

You are getting into religious territory. 😉 It would be totally fine to take quality electrolytes with the same specification as the old ones. That will serve you well. If you want to treat yourself and/or the board, you can go full polymer. It has advantages: Lower ESR keeps caps cool and improves the voltage output. Polys are usually also smaller than their electrolytic counterparts. Often you can go with lower capacitance values due to the better ESR. However, many people ignore this, the change of ESR can have influence on the regulators feedback loop and regulation ability. Normally you take the ESR into the equations for that. But usually you don't go wrong with propery polymers that are equal or better in their spec than the original counter-parts.

ubiq wrote on 2026-05-08, 17:12:

Heh yeah, my dude. I feel like that's kinda Noctua's ethos anyway with them stubbornly sticking with their ugly brown fans. Tha […]
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RetroLizard wrote on 2026-05-08, 12:03:

TheMobRules wrote on 2026-05-08, 06:00:

Huh. Personally I've yet to see evidence that a ball bearing fan can be properly refurbished with light oil, especially considering ball bearing fans use thicker grease instead of oil as lubricant, so even if you manage to get oil in there it's going to mix with the old solidified grease remains. Here's an interesting document from NMB (a renowned fan manufacturer) comparing sleeve and ball bearing fans.

Ah, that seems like a good price for the Noctua... I really dislike their brown/beige or grey color schemes and prefer regular black fans for my retro stuff, but performance wise they're good.

Color schemes don't matter much when I'm gonna have the case closed up.

Heh yeah, my dude. I feel like that's kinda Noctua's ethos anyway with them stubbornly sticking with their ugly brown fans. That said, they're so overwhelmingly popular now that the Noctua colours as status symbol may override taste.

With Noctuas, I've read some worrying that they could potentially prioritize low noise over sufficient CFM for all applications. Regardless, proof's in the doing: I use one on my XP 2600+ and it keeps it nice and cool.

May also want to consider general airflow in your case, depending what you're working with - an extra 120mm pushing the hot out the back can do a lot of good.

What are the dimensions of your Noctua fan?