I was looking for an S.7 motherboard among the MBs, yes that's right, but although most are grouped, with the indication of each card, there are others that are instead in a box 📦, without it being written what the content is.
So sometimes I find motherboards, which I repaired or started to repair, or boards that after a component replacement intervention, have not given signs of life, so after some time ⏱, they are re-examined in search of a solution, hoping to make them work again.
Some time ago, I don't know exactly how long, but it could be a couple of years (?), I replaced several capacitors on an S.478 motherboard.
This is one of the first models with VIA chipset and DDR RAM, so P4/400, the card is a "AZZA P4M2-MVB", as mentioned above, I replaced several electrolytic capacitors, except for one of the SACON 3300uF 6.3V, well today as a surprise 😱, I discovered that that one also needs to be replaced, you can see a bulge at the top, and this is a sign that it needs to be changed.
I should have a spare capacitor, I would like to use a Nichicon equal to the other six, from memory I don't remember if this motherboard has been tested or not, however we will have to wait for the replacement of that capacitor, to do a start-up test.

Chkcpu wrote on 2025-10-26, 16:59:

Ciao Elio, […]
Show full quote

Ciao Elio,

Thanks to @Ydee’s nice find of the Zida BIOSes, I was able to check the latest 5SVA-E Rev 1.40e BIOS.
I has indeed K6-2 support up to 400MHz, but no K6-III or K6-2+/III+ support.
It is also limited to 32GB IDE drives.

Cheers, Jan

Hi Jan,

there is one newest BIOS for Zida, its version 1.41 - but it's very hard to detect changes from previous versions - Zida didn't mention them anywhere, and the only description was provided by the brand's former distributor in the Czech Republic, Levi International, which still maintains a site with BIOSes and manuals for old Zida boards. And BIOS v. 1.40 is already modded for support HDD bigger than 32GB ( up to 128GB, I have it on the 5SVA rev 1.2 board and the 80GB disc works without any problems).

Ydee wrote on 2025-10-27, 16:29:

Chkcpu wrote on 2025-10-26, 16:59:

Ciao Elio, […]
Show full quote

Ciao Elio,

Thanks to @Ydee’s nice find of the Zida BIOSes, I was able to check the latest 5SVA-E Rev 1.40e BIOS.
I has indeed K6-2 support up to 400MHz, but no K6-III or K6-2+/III+ support.
It is also limited to 32GB IDE drives.

Cheers, Jan

Hi Jan,

there is one newest BIOS for Zida, its version 1.41 - but it's very hard to detect changes from previous versions - Zida didn't mention them anywhere, and the only description was provided by the brand's former distributor in the Czech Republic, Levi International, which still maintains a site with BIOSes and manuals for old Zida boards. And BIOS v. 1.40 is already modded for support HDD bigger than 32GB ( up to 128GB, I have it on the 5SVA rev 1.2 board and the 80GB disc works without any problems).

Hi Ydee,

Thanks for these 2 additional Zida 5SVA-E BIOSes.

I found the modded v1.40 BIOS with 128GB IDE HDD support as well. It is one of the BIOS mods by the Wim’s BIOS team and team member Rainbow still maintains a website with all these BIOSes at http://wims.rainbow-software.org/index.php
This BIOS fixes the 32GB IDE HDD limit, but has no other improvements and has the same CPU limitations as the original v1.40.

The “unknown” v1.41 BIOS piqued my interest, so I looked at this BIOS in detail.
It appeared to be the same 06/19/1998 BIOS as v1.40, but with a few BIOS Setup default changes. The v1.41 Enables BIOS Options like Video BIOS Cacheable, System BIOS Cacheable, and OnChip USB by default. The v1.40 has these options as well but has them Disabled as default. But you can aways Enable them if you want.
The v1.41 BIOS also clears all BIOS PnP data (the ESCD block) when you select Load BIOS Defaults in the main CMOS Setup menu. This is highly unusual.

For the rest, this v1.41 BIOS is identical to the v1.40, so it is not a new build.
The changes in v1.41 can easily be made with Award’s MODBIN tool and it looks like the distributor made these changes themselves, maybe on request of a client.
I personally prefer the defaults in the v1.40 BIOS. 😉

Cheers, Jan

Ydee wrote on 2025-10-27, 16:29:

Chkcpu wrote on 2025-10-26, 16:59:

Ciao Elio, […]
Show full quote

Ciao Elio,

Thanks to @Ydee’s nice find of the Zida BIOSes, I was able to check the latest 5SVA-E Rev 1.40e BIOS.
I has indeed K6-2 support up to 400MHz, but no K6-III or K6-2+/III+ support.
It is also limited to 32GB IDE drives.

Cheers, Jan

Hi Jan,

there is one newest BIOS for Zida, its version 1.41 - but it's very hard to detect changes from previous versions - Zida didn't mention them anywhere, and the only description was provided by the brand's former distributor in the Czech Republic, Levi International, which still maintains a site with BIOSes and manuals for old Zida boards. And BIOS v. 1.40 is already modded for support HDD bigger than 32GB ( up to 128GB, I have it on the 5SVA rev 1.2 board and the 80GB disc works without any problems).

Chkcpu wrote on 2025-10-27, 19:16:

Hi Ydee, […]
Show full quote

Ydee wrote on 2025-10-27, 16:29:

Chkcpu wrote on 2025-10-26, 16:59:

Ciao Elio, […]
Show full quote

Ciao Elio,

Thanks to @Ydee’s nice find of the Zida BIOSes, I was able to check the latest 5SVA-E Rev 1.40e BIOS.
I has indeed K6-2 support up to 400MHz, but no K6-III or K6-2+/III+ support.
It is also limited to 32GB IDE drives.

Cheers, Jan

Hi Jan,

there is one newest BIOS for Zida, its version 1.41 - but it's very hard to detect changes from previous versions - Zida didn't mention them anywhere, and the only description was provided by the brand's former distributor in the Czech Republic, Levi International, which still maintains a site with BIOSes and manuals for old Zida boards. And BIOS v. 1.40 is already modded for support HDD bigger than 32GB ( up to 128GB, I have it on the 5SVA rev 1.2 board and the 80GB disc works without any problems).

Hi Ydee,

Thanks for these 2 additional Zida 5SVA-E BIOSes.

I found the modded v1.40 BIOS with 128GB IDE HDD support as well. It is one of the BIOS mods by the Wim’s BIOS team and team member Rainbow still maintains a website with all these BIOSes at http://wims.rainbow-software.org/index.php
This BIOS fixes the 32GB IDE HDD limit, but has no other improvements and has the same CPU limitations as the original v1.40.

The “unknown” v1.41 BIOS piqued my interest, so I looked at this BIOS in detail.
It appeared to be the same 06/19/1998 BIOS as v1.40, but with a few BIOS Setup default changes. The v1.41 Enables BIOS Options like Video BIOS Cacheable, System BIOS Cacheable, and OnChip USB by default. The v1.40 has these options as well but has them Disabled as default. But you can aways Enable them if you want.
The v1.41 BIOS also clears all BIOS PnP data (the ESCD block) when you select Load BIOS Defaults in the main CMOS Setup menu. This is highly unusual.

For the rest, this v1.41 BIOS is identical to the v1.40, so it is not a new build.
The changes in v1.41 can easily be made with Award’s MODBIN tool and it looks like the distributor made these changes themselves, maybe on request of a client.
I personally prefer the defaults in the v1.40 BIOS. 😉

Cheers, Jan

Thank you both very much for the suggestions and for the info on the BIOS.
Reading in fact I would say that I would also go to update the original BIOS, with the VER:1.40 one.
Greetings

Going back to the PC socket 7, since in the one with MB ACORP A-5VIA3P it is not possible to use the Cyrix M II-333GP, because it does not work stably beyond 233 MHz, I should see among the Cyrix CPUs that I have in my collection, if I have any that I can try, I think I have the 300GP that I had put, before changing it years ago with the 333GP.

Clearly, I would also avoid CPUs with FSB 75, because even at this frequency, I had problems.

Maybe it could be solved by changing some components of the line of regulators, then electrolytic capacitors and linear regulators, but honestly it doesn't seem like the case, because maybe they are ruined, for use at higher frequencies (more heat), and so if I initially solve, later I could find myself with the same problem, which for the record has already happened with an i430VX and a P200.

Regarding the ZIDA 5SVA-E, I was waiting for news about the BIOS, thanks to the friends of Vogons, I will use a BIOS VER: 1.40 correct, there is a VER: 1.41 but it has some slight difference, although in practice it is almost the same.

Finally I was looking for another S.7, which I haven't found yet, it would be an ASUS VX97, with damaged chipset pins, for convenience it would have to be replaced, even if with patience and the right tools, the pins could be fixed, and recreated the missing ones (possibly), which I remember has a VRM with switching regulators, and supports various CPUs beyond the 3.5X, it seems to me that it has the third jumper for the multi from 4X to 5.5X, but I go from memory, it may not be like that.

I downloaded all the BIOS of the links, there are both the first and the last, that is, the REV: 1.0 up to 1.41.
Looking at the files contained, regarding the updates, I noticed that it would seem the same for both motherboard models, that is, both the 5SVA and the 5SVA-E, use the same BIOS (?).
You have to pay attention to the REV of the MB, and to the two VT82C587 chips near the SDRAM, it seems that there may be differences, and in some cases it cannot be used.
So I looked at my card, just to see if it's among those that have no problems.
I can't say for sure, but there's a line written on the chips, which could be the right one.
But it also talks about 64 MB DIMM, so I don't know if the reference is for the RAM or for the BIOS (?).
One last warning ⚠️, it says not to use BIOS 1.3 or later on VER: 1.2 cards, it's not very clear to me if it includes VER: 1.0 cards or only 1.2.
Looking on the Internet, I found some info about it, it says that the BIOS is not the same for 5SVA and 5SVA-E, in short, if there was a doubt, now it has not disappeared.
Other info about the memory, it says that the maximum capacity DIMM modules are 64 MB, in fact I don't remember if in the past I tried 64 MB SDRAM, eventually I could try, if you want you could use the DIMMs together with the SIMMs, it's not something I would do, but I could do if you need to have more RAM than 64 MB.

Found that ASUS VX97, with damaged chipset pins, it was right among the cataloged cards but I hadn't noticed it, today looking better, I found it right away.

Let's start by saying that there is no third jumper for the multi, there are BF0 and BF1, and from what I see, in this card it was not expected, maybe it was added in the subsequent REV., on my 1.01. so you can't put CPU with multi from 4X to 5.5X, except with a change to the MB, fortunately it is possible to use for the K6-CXT the 2X, which is automatically remapped to 6X.

For FSBs I read the settings for 50 60 66.6 55 75, with the corresponding 25 30 33.3 27.5 37.5 MHz of the PCI.

On the motherboard it says for the VCORE, 3.5V 3.4V 2.9V 2.8V 3.2V, but there could be the possibility of getting lower voltages, even if it only has three jumpers, and this could be a limit, for now I don't think you need to know anything else, since the board can't work.

Already because it has almost a row of damaged PINs, on the side towards the ISA slot, of the Intel SB82371SB chip, some seem to have vanished, the rest is quite bent, and could be fixed, only if you are able to reconstruct the missing ones.

I don't know how you can damage a chip like that, maybe they were trying to do something nearby, the simplest solution is to replace the chip with another replacement one, but replacing it is not so easy, for me it is impossible since I don't have the right equipment to do this job, but given the current conditions, I could start straightening the pins, and see if the missing ones are connected to something, that is, if maybe they are not needed, I would avoid work in trying to rebuild them.

Update on the ASUS VX97, on the previous pages there is the setting for the VCORE, thanks to Jan, you can select voltages from 2.0V up, usually the ones you need are 2.2V and 2.4V (for K6), but if you need it with CPU for laptops, you can use the combination for 2.1V.

I tried to straighten some PINs of the chipset, of the ASUS VX97, there are so many, and very bent, I managed to recover a couple (now unusable) from under the chip, and the result is that from how reduced they are, now everything is wasted time, because those put worse, in an attempt to straighten them, weaken and detach on one side.
Having the replacement chipset, it would not be a problem at all, you could break them all, and then clean up the area where the pins were welded to the motherboard, this could be done in the absence of a hot air welding station, while for the welding of the new chipset, you could succeed with a normal welder, maybe if it has the fine tip, it could be better.
The motherboard, apart from this damage, doesn't even look so bad, the visual aspect is excellent, so it would have a good chance of working again, although I can't explain yet, how is it possible to do such damage (?).
Other friends not from Vogons, they told me they wanted to resurrect a 486, of motherboards like that, I have a few (not many), on one I had started the work, it has UMC Chipset and 2 OLB slots (Opti Local BUS), visually it looks like an EISA, on the motherboard it says 4FLUD-1.0, the first boot attempt was negative, probably due to corrosion (quite limited), you notice a trace under the keyboard BIOS socket ⌨️, very corrod, because near the - of the battery, it then passes to the back of the card, I thought I would make a bridge and see if I get post codes, unlike now (— —), for the rest I am quite confident, the conditions are very good, except for the BIOS socket, which I would have liked to replace, but it is welded in tiny pins, and it is easy to damage them.

Today I will try to do some checks on the 486 motherboard (4FLUD-1.0), observing better the area near the socket of the keyboard BIOS chip ⌨️, the tracks to be repaired are three, two are right under the plastic of the socket, that's why it would have been better to remove it, but I could do something, the idea is to follow the tracks, and check the continuity from two distant points, if I find one interrupted, I could take a step forward, or even solve it.
Of course it is not said that a problem has been solved, there is no other to solve, but much depends on the interrupted track, if it powers the BIOS chip, that could be the problem (?!).
I have to check my notes 📝, I might have found something else to fix, which I don't remember, in the meantime I'm reading something about a 386 that has similar problems, interesting 🧐 are the explanations on the LEDs of the postcard.
From what I understand, some LEDs are only used if connected to PCI, so on or off, when the card is ISA, it doesn't matter, or it could report something else (?), I have no idea 💡 of what.
It would have been better, to remove the socket of the BIOS Keyboard chip ⌨️, unfortunately 😣 the pins and tracks are tiny and delicate, I tried to release some pins, it doesn't seem like a good result, and I stopped because I would have damaged the remaining ones, an alternative would be to cut all the pins, and then free the individual holes, or solder to the new socket to the protruding pins.
The advantage of removing it is because on the battery side, the pins are oxidized (green), and then you would have free access to the tracks below, which are not visible because they are covered.

As anticipated, I reviewed the notes on the 486 4FLUD-1.0 Motherboard, the card arrived complete with both RAM and CPU, to be precise there are four SIMM 30 PINs of 1 MB each, in total so 4 MB with NEC chip, and for a simple boot test they are fine 😌 (as long as they work!).
The CPU is an Intel 486DX2-66, there is no heatsink, and on the CPU it is not written that it is required, but for safety I will add a temporary one, so as to prevent it from heating up too much, and that this creates problems.
In the first attempt to repair, I focused on the top, a couple of large tracks seemed to be able to be interrupted, in reality although they are quite corroded, they are not interrupted.
I had later tried to remove the 40 PIN socket, of the BIOS keyboard chip ⌨️, about half of the sockets are a little oxidized, and on the opposite side to pin 1, near the - of the battery, it covers four tracks that I will go to examine 🧐
I didn't continue, to try to remove and replace the 40 PIN plinth, because in the back there are tiny tracks, and trying to remove the tin, I think they can be damaged, the PCB seems fragile and the tin very hard.
Regarding the four tracks under the 40-PIN plinth, one is wider, and the other three are medium-sized, measuring about 0.3 mm, I tested the continuity, and I discovered:
The wide one, even though it's corroded, is fine 👌
The three averages, on the other hand, are all interrupted three 👎
Looking at what 😨 they are connected to, it is likely that after restoring the link, the motherboard may show post codes, and later a video BIOS screen.

Before starting work on the Modula Tech 4FLUD-1.0, the 486 motherboard with two OLB slots, I checked on TRW the existence of manuals and the presence of one or more BIOS.

First of all, it seems to me that 4FLUD-1.1 is much more common, which should be a version later than 1.0, so I have a motherboard first version, probably in the next one some additions or corrections were made.

It will be interesting, if it works again, I imagine that the BIOS may also be the original one, I don't think it's very different, but could it differ in something?

For the repair, I will make bridges with thin electric wires, it would have been better, if the track was broken superficially, the problem instead is in the passage holes at the back, so I will connect the upper part to the lower one, with mini-wires, aesthetically I don't like it very much, but the important thing is that it works, the aesthetics can be evaluated later, if you use another system as an alternative to mini-wires.

Finished a little while ago, the work on the Modula Tech 4FLUD-1.0 motherboard, a motherboard of the first generations of 486, perhaps probably one of the first that looked for an alternative way, there are in fact a couple of OLB slots, quite rare and maybe there are a couple of video cards for OLB, I don't know if it's compatible with EISA, honestly I didn't understand it.(?)

The problem was in three corroded tracks, in particular it was the passages from top to bottom that had interruptions inside (?), since I don't have professional equipment, I repaired the tracks in a fairly rough way, aesthetically it won't be the best, but I tried to make bridges, so that they had a minimum impact, that is, that they were seen as little as possible, unfortunately I had to bypass the 40 PIN socket, because two tracks passed underneath, I welded three small wires, and I restored continuity, to finish I put a small amount of hot glue, to keep them still, and avoid That they can move and in the long run detach.

After the welds, I reassembled the two BIOS chips, the card has both RAM and CPU, I add AT keyboard, ISA video card (WD90C00-JK chip), and the ISA post card, which I use as a speaker, finally I put on the CPU a chipset, connected an ATX power supply with AT adapter, monitor and power cords, I turn on, and I notice a code in the post card display, then other codes begin to appear, and you hear the noise of the RAM count (disappeared over the years), finally there is the video BIOS screen and other beeps warn that you can press F1 To enter the BIOS, the BIOS is an AMI, of the color type typical of PCs of that period.

In short, it works!!!

And I really like this 486, now I should study an ideal configuration, at the moment I would say it's fine, even if it only has 4 MB of RAM, I didn't think about increasing them to 8 MB or more.

So if I wanted to bring the RAM to 16 MB, I would have to get some expensive 4 MB modules each (30 PIN), there are even those who have made 16 MB each, but four I imagine cost really too much, even if 64 MB could be convenient using Windows 98SE, while with only 4 MB you could use DOS and Windows 3. X, or there would be the OS/2 alternative if you want to use something else.

After the success with the 486 motherboard, now I have to start defining the final configuration, for the moment it's fine, in the sense that I don't need any more RAM and I'm fine with the 486DX2-66, I have four other DX2-66 but they are all VLB, later I could update one or two of the VLB PCs, just to differentiate them, some have support for low-voltage CPU, I could for example make a 486DX4-120 or a 486DX2-80, if I want I have an Intel DX4-100 or an AMD 5x86-133 P75, but these for the moment, I would keep them waiting for a 486 PCI, which I could repair In the future.

I would start adding an ISA controller, to be able to use a 40PIN IDE-CF adapter, with a CF memory card, and given the minimum amount of RAM, I could use a 64 MB one, where to load MS-DOS, and if necessary Windows 3. X.

Originally, the 486 PCs did not have CD players, but they were added with a multimedia kit, along with an ISA sound card, and initially they were connected through a special port, then with the transition to 4X speed, they switched to the 40PIN IDE ports of the PC.

As a video card I have a couple of ISA cards, a CL and a WD, both 1 MB, which would be fine on this PC, surely if I had an ET4000 ISA or a 2 MB card, I would use that one.

Of ISA sound cards, I have some, but I don't think I'll use the older ones, because I would use them on PC 286 or 386, I was thinking of using one from an HP PC, it has a trapezoid shape (or triangle), currently I have no idea which PC it was installed in, I hope it's not too modern, compared to the motherboard.

Finally, what else could be needed?

I don't think you need anything else, of course it would be convenient to have a PS/2 mouse port, or USB ports, but using the CF memory card, you can do without USB ports.

A LAN card or a modem could be useful, but they are not essential, if I wanted to exchange data with another PC, I could use a Laplink cable, and its program.