I'll be back briefly on the Soyo 5BT5, for the moment I'm working on the ABIT SE6, but I also have the Gigabyte AM2 waiting (hopefully soon), these two jobs at the moment have precedence, but I'll put my feet back on the SOYO (later), I'll see fix the cache chip with a missing pin.

Among other things to do there will be the change of CPU, with a dual core, initially I would use a P.MMX, but the final goal is a 400 or 450MHz K6-2, so for this last frequency it would be very usefull The setting with the 32MHz PCI (instead of 37.5), unfortunately with the P.133 (P54) doesn't work, but could it be a CPU problem? -I have no idea- But I hope so.

Just for the record, the frequency generator is an ICS 9148BF-04, on I.N. I found a pdf where besides the normal combinations (shown on the MB), there are three other secret ones, one works and it's the one called 68.5MHz Turbo, currently I use that instead of the normal 66.7MHz, while the other two are for 75 and 83.3 with PCI at normal frequency (32 and 33.3), therefore a divisor greater than 2, of course if the non-functioning of those settings does not depend on the type of CPU, it is strange that they used that "generator", above all because I found that it is used on other S.7 motherboards, in particular, I found one on an ACorp 5VIA5S, but strangely on the serigraphs of that card there are not those two secret settings at reduced PCI speed.

I'd find it a little strange that they don't work there either, I wonder why put that generator if you can't have those particular settings available, here's the next step I'll do is look for the manual, maybe I'll find some info on the CYRIX settings, because I think serves above all to those particular CPUs, I remember that the first 6x86 P200 went 150MHz (75X2), this was a frequency that not all the cards of the period supported, furthermore the PCI worked at 75/2=37.5 frequency which could create problems, I did a 75/32= calculation resulted in a divisor of about 2.33, this allows for high FSB and normal PCI operation, I think it is very reliable and faster (than 66.7).

However, just to see I put some pictures of this card, taken from one on sale, the price is high for me, now it's been a long time since the prices have gone up, you can find cards that don't cost much but usually have some problem operation.

In my spare time I started repairing an S.478, an ASRock P4VT8+ Rev. 1.06, I repaired an identical board in the past (but Rev. 1.04), the main problem is some capacitors to replace (3300 uF 6.3V) , having the same new ones I removed them, out of five total, four had high ESR and were at a loss, the only one that was in better condition had a capacity of over 4000 uF, therefore a little beyond the tolerance, the new ones ( Panasonic) are perfect.
There is another job to be done on the back of the SB, an SMD capacitor is missing, I recovered a very similar one (identical?), the dimensions are the same, and the color too (brown), it just needs to be soldered, but for that work serves a soldering iron with a fine tip, on one side it is close to other smaller SMDs, you have to be careful not to detach them, soldering the missing one.
But today it was not possible to solder them (lack of time), if I can I will do it tomorrow, together with the other two motherboards already ready (for some days), an ABIT SE6 and a Gigabyte GA-M55S-S3.
https://www.asrock.com/mb/photo/P4VT8+(L1).png

This morning, I found some time to fix a motherboard (ASRock P4VT8+ REV. 1.06), the bulk of the work had been done not so long ago, it only remained to re-solder some capacitors (5) and an SMD, the most the SMD was difficult, even if it wasn't very small, it was very close to the others, when soldering you had to be careful not to touch the nearby ones, with the help of tweezers I was able to position it precisely, re-soldering it wasn't easy, but after a few attempts the welding was successful.
Just to remind you, the SMD is in the back under the SB, and it was brown, the recovery one is the same color, and it should be a capacitor, since it was signed as Cxx, unfortunately there isn't in the motherboard no screen printing, but I assume that color there are only capacitors.
I soldered the new electrolytic capacitors, 3300uF 6.3V from Panasonic, in total there are five pieces, I removed all the same (original) ones because some were swollen, a couple looked visually fine, actually after checking them, one was leaking and the other had higher capacitance (beyond tolerance), I think it's a common problem with other motherboards of the period, I'm in the CPU area, in the past I changed the same capacitors, in an identical motherboard but REV. 1.04.
The last thing to do is reassemble the hook for the CPU cooler, I had removed it to work better, just reinsert it and press down the four retention pins.
Some welds didn't turn out really well, but they still guarantee the connection, I don't think I'll do them again, especially if trying the card, it works.
For this I have to look for a test CPU, a DDR memory (possibly 400), a VGA AGP (8X possibly), or a VGA PCI, and everything needed to do some tests, then also an IDE-CF adapter with memory card , containing some DOS software for Bench and Info.
I think it was a fairly cheap card in its day, and that it was used in some PC builds, still today there are some in circulation, I have no idea of the performance, but I suppose they are slightly lower, since it has a VIA chipset, those with chipset Intel should do slightly better (?).
Unfortunately being a socket 478, it is not possible to install dual-core CPUs, but the latest generations of those CPUs had the HT, which simulates the presence of a second core, and improves performance.
Strangely that technology was not used in the following Core LGA 775 (Dual Duo Quad) CPUs, perhaps because having two real cores, the benefit would have been much less, and therefore, it was preferred to eliminate that part of the circuit, simplifying it.
I'll try to test it as soon as possible, and post some pictures, before and after the repair, plus some other pictures of the BIOS and DOS programs.

I recently bought various material, an Acer MB with i5 third gen. 3.1GHz, with 8GB DDR3, this will serve as the basis for my new internet PC, as the current one is now dated, hp msi motherboard with Athlon 64 X2 3800 S.939, 4GB RAM DDR 400, I'll try to get it later changing HD with an SSD, but also wanting to improve it (update something), probably wouldn't make a big difference compared to now, moreover the replaceable components cost a lot, I am thinking for example of a 4400-4800 cpu (939).
Another motherboard I bought is a Compaq Camaro, it's actually a Mitac, it has an AMD K6-2 475 (set if I'm not mistaken at 485 - 5X97), the video is integrated in the VIA MVP4 chipset, the audio it's cheerful ESS (integrated), there are only four PCI slots, so no AGP and ISA, as soon as I can I'll do some tests, and see if it works.
Another purchase I made is a pair of CPU+FPU, TI 486DLC40 and IIT 4C87DLC-40, in practice with these I could upgrade the 386DX40 (see page 1), or simply use them to see how much difference they make, from that I don't know, it should be with the DLC at the level of a 486DX33, so it might make the PC a bit faster.

I realized now that I didn't put the photos of the ASRock 478, here these are the ones where you can see the finished work.

Today I tested the Compaq Camaro (Mitac 5114VU) motherboard, unfortunately I didn't get any screen shots, I checked the jumper settings, and they are all right, I tried various RAMs, to no avail, the board doesn't need anything else besides the RAM and the CPU, the VIA MVP4 chipset has both video and audio integrated, unfortunately in the manual I can't find the pins for connecting the speaker, assuming they exist.
Starting up everything proceeds normally, some codes appear on the post card, but in a moment they stop on 2F 2E, honestly I didn't quite understand what that 2F indicates, I reset the BIOS but nothing changed, changing Ram with other modules at sometimes it stops before, but it never went beyond that 2F (at least for now), i think i check the cpu, but i don't think it could be faulty, i currently have an amd k6-2 475, i will try another one with a different frequency, at could it sometimes boot using slower cpu?.
Any suggestions are welcome, thanks for your cooperation, I hope to understand something and get results soon.

I continue the work on the Compaq Camaro motherboard, I did some tests, changing the RAM, using both PC100 and PC133 modules, but it didn't unlock, it remains stuck on the same error codes, I used some modules that are fine in all PCs , but in the end I chose a couple (with a hp label), both should be 64MB (one says), one is double sided (chip on both sides), the other is single sided, I don't know what RAM Compaq used on that PC, but I think these two hp, they could be fine.
After several boot attempts, the pc stayed on for some time, at one point, it displayed a later error code, but unfortunately I don't have any BIOS screen on screen, so, there's always a problem which causes the boot to hang.
Unfortunately, having no ISA slot, I can't put a VGA ISA in it, to see if there is a problem with the BIOS, and it doesn't help the lack of speaker connector, I can't connect any speakers, and I can't hear any beeps, this would help understand what could be wrong.
Another test performed, is the CPU change, I removed the K6-2 475, and put another 300 MHz K6-2, I selected the jumpers for 3X and 100, if I wanted I could select 4.5X and 66 (but not the 'I did), even with the other CPU the codes displayed are always the same.
A further test that I could do is to change the CPU again, this time I would use a P.MMX, so I would be sure that it doesn't depend on working but defective CPUs, because out of three at least one should be perfect, but I'm pretty sure that the CPUs work, and that the problem is elsewhere, for example it occurs to me that I have not connected the floppy drive, in this way I could see if the led flashes, or if it tries to read a floppy disk, a sign that it is trying to perform the BIOS recovery.

I try again to work on the Compaq Camaro problem, for those who have not read what was previously written, I can say that the card starts up, but the screen remains black, and the PCI Post Card stops on 2F 2E codes, even if once the 2F code went fine, moving on to the next one.
I tried booting without the RAM, and the error codes are still 47 43 (this time), this could mean, that the RAM is working, and something else has a problem, thinking it could be a bad CPU, other than the two tried previously, I put another K6-2, this time a K6-2-500, but there is no change, with the K6-2-300 I tried the setting 4.5X and 66 (instead of 3X and 100), that doesn't work either, I tried to bring the VCore to 2.3V, to see if the VCore voltage was the problem, unfortunately that doesn't work either.
I measure the voltages on the mosfets, to identify any strange values, on the cpu side we have two 32N03-L (Q4 and Q5), following the normal PIN numbering, i.e. Pin1 on the left, Pin2 in the center, and Pin3 on the right, I get the following readings :
Q4
Pin1) +5.72V
Pin2) +2.09V
Pin3) +0.02V

Q5
Pin1) +6.94V
Pin2) +4.93V
Pin3) +2.09V

So far everything is normal (in my opinion), so I move on to two other mosfets near the PCI slots, Q3 and Q6, it seems to say F E99AR, the 99 cannot be read well, however I try to measure:
Q3
Pin1) +1.25V
Pin2) +2.47V
Pin3) +4.95V

Q6
Pin1) +1.99V
Pin2) +3.22V
Pin3) +4.93V

I also measure the coils near the mosfets Q4 and Q5, on L38 I have +4.95V, while on L36 I measure +2.22V, this should be the voltage for the core.
Finally there is a similar transistor, signed Q1, I measure +4.94V in Pin1, the second pin (Pin2) should be a mass, because I measure +0.03V, finally on Pin3 I have +11.40V.

So I'd say that reading the values I don't see anything strange, then it's not said, but there doesn't seem to be a lack of voltage somewhere, the next measurements, I think I'll do them in the Pins of the PCI slot and in the Pins of the RAM. Hoping to find some abnormal or missing voltage.

Unfortunately I didn't have a chance to do any more measurements on the Camaro today, so far, I don't see any outliers or missing voltages.
But I'll spend some more time trying to figure out what's wrong, and if I can finally get it going.
That's not the only board I have in repair, I have various kinds, let's say from 486 to 775 or AM2, I also have some with later sockets, but I don't have everything I need to try booting, I lack RAM and the CPUs, and for the moment I'm keeping them aside, maybe in the future if I find the necessary I can test them.
One card I should try again, is an S.4 with Pentium 60, some time ago I restarted it, using a PCI video card, because I didn't have a VGA port connector to connect to the MB, the motherboard has a video chip on- board, I think with 1Mb of Ram, the board if I'm not mistaken is an intel hendrix, intel chipset and 48MB RAM (72 PIN), I probably put some images here (see previous pages), anyway it would be like this (image taken from IN) , then ISA and PCI slots, in AT format.
For the integrated VGA I bought a connector on IN, when it arrives I have to check the PINs, I hope no modification is necessary and that it is enough to insert it, and above all it works.

I temporarily put aside the Camaro, to devote myself to a PCChips M550, in reality it is the same but it is of a different brand, as you can see it has more names, but it is always the same motherboard, both were bought by the same person, and according to him, they were working, reality showed that both don't work, they probably have the same defect, from what I understand, I guess there is a BIOS problem, maybe an update gone wrong, if so there would be no HW failure, the only thing to do would be to rewrite the BIOS chip with a correct version, for the M550 it seems to be possible to do it from floppy, I haven't tried it yet, but from previous experiences, if the floppy has no bad sectors, it takes just a few minutes to get the PC back up and running.
Unfortunately I don't have an adapter to reprogram the chip, otherwise I could do it without using the floppy disk.
As you can see from the codes of the post card, when starting the pc tries to read the floppy, I imagine you are looking for a file like AMIBOOT or similar, having not inserted any disk, it emits an infinite beep at each failed attempt.

Small update on the M550, to avoid any doubts I performed the CMOS drl reset, moving the jumper (reset shortly after), unfortunately nothing has changed, the post card hangs on the same error code, and the floppy drive tries the reading on floppy (even if not inserted), at each failed reading attempt the speaker emits a beep, indefinitely.
My next move is to download a copy of the BIOS from IN, put it on a floppy disk, and see if reading that file starts the Recovery BIOS.
In that case, if I'm successful, the card should be fully functional again, the alternative would be to rewrite the chip, but I don't have an adapter for that BIOS chip, nor an adapter to plug into the chip socket (on the MB), to be able to use different types of chips.
Unfortunately I encountered a big problem with the DIMM RAM sockets, despite exerting considerable force, I cannot insert the RAM, if I manage to do it on one side, on the other it disengages and jumps off, in short, perhaps it is better to change the sockets , unplugging the ones currently present, for the moment I use 72 pin RAM, but I would prefer to use DIMMs.

Today I got an AMD K6-2+ 400MHz, a cpu that has integrated L2 cache (128KB), this is usable on motherboards with VCORE lower than 2.0V, but I know they can also be used with voltages up to 2.1V, obviously if you are below 2.0V it will be better.
A lot depends on the motherboard, usually the minimum selectable is 2.0V (without jumper), other older cards don't go below 2.5-2.8V, but there are some cards that can go down to 1.8V or less. Obviously having one of these cards, the 1.6V CPU can be installed without any problems, the slight 0.2V overvolt will be tolerated without creating problems.
Otherwise, what to do?
Here the simplest solution is to use it in boards with a minimum voltage of 2.0V (without jumpers), but what if instead we wanted to go below 2.0V? What could be done? The solution could be found in some old site, assuming it is still online, or having knowledge of electronics, you could make some changes. Well, personally I don't have such knowledge, and therefore I wouldn't know if a component can be replaced with another, but over time I have made numerous measurements on the mosfets, so I assume that when you measure on the 2.0V mosfet, that is the voltage that reaches the CPU, so I thought, usually after the mosfet there is an inductor, if I detach one side and insert a resistor in series, I could lower the voltage to 1.6V or 1.7V (depends on the value used), if this were actually the case, it would be perfect!
The same thing could be done with motherboards that do not go below 2.8V, bringing the voltage to 2.2V or 2.0V, or even 1.5V or 1.6V, you could install newer K6 CPUs, or a 2.2V Cyrix (assuming you have one), perhaps for the sole purpose of benching.

Today I will try the Acer MB with intel i5, at the moment I don't think it can be considered an old card, but having more than ten years, it will be in a few years.
Initially I will try it with the minimum hw necessary, both video and audio are integrated, there would also be LAN, but according to the seller it doesn't work, to get around the problem he provided me with a PCI-E 1X LAN card, in below if the integrated one does not go, I will use it.
The motherboard is Acer, but it's probably made by others, maybe ECS??? The model is H61H2-AM3 V.1.0, the CPU is a 3.1GHz third generation i5 (quad core), the integrated video I don't know if it's in the CPU or in the chipset, but alternatively you can put a PCI- And 16X, possibly a better model than the present one.
I had some doubts about the F_Panel connector, I didn't know which pins to short-circuit for the startup, and for the connection of switches and LEDs, but they vanished as soon as I found the serigraphy, strangely it is located in a distant point, and only after a long and careful research, I managed to locate it, it is a bit hidden in the RAM area.
Speaking of RAM, I only have one 8GB DDR3 hyperX module, but later I want to add a second identical module, to make them go into dual channel.
For the tests I will use the usual ISA-PCI Post Card, I hope to have (positive) news soon, if all goes well, the next step will be to complete the configuration, adding the drives, I will use a different power supply from the Acer PC one, a Corsair CX750 (non-modular), currently it's the best I have (working), later if I need it on another PC, I'll use another similar one.

Tried the Acer i5 MB, it worked, it booted without any problems, even though strangely, the post card doesn't show any code.
I remember that:
Motherboard is Acer, model is H61H2-AM3 V.1.0, CPU is 3.1GHz 3rd generation i5 (quad core), video and audio is integrated, LAN is also integrated, but I need to see if does it work, seller says no.
As RAM, I only have an 8GB DDR3 hyperX module, but I later added a second identical module, to make them go into dual channel, in total I now have 16GB of RAM.
The HD is a 240GB SSD from SanDisk, the OS is Windows 8, I ran the classification of the PC using Windows, the results are quite similar, except for the video (average), then I think I need to add a VGA , in the PCI-E 16X slot, I don't have a precise model in mind, but I'd like something that scores similar to the rest, say 7.5 or higher.
Having a 750W Corsair, I shouldn't have any problems powering a particularly demanding video card (of W), for the rest I'm waiting to put everything back in the case, but the PC is already very silent.
I haven't tried the audio yet, and I think it works, also we should try the PC on the Internet, via usb-wifi.

I temporarily put aside the two S.7 motherboards, Compaq Camaro and PCChips M550, right now I don't have the time to download and update the BIOS, for one of them I should try from the floppy disk, the other having the soldered chip, it's more complicated, maybe I should self-build an MF adapter to connect the programmer?
Remaining on socket 7, in the past few days, I put my paws on an ASUS P55T2P4, with i430HX chipset, I tried to start, with a P.MMX 200MHz, 16MB RAM (8x2) 72 PIN, a provisional VGA SIS 6215 PCI, and after a few attempts they managed to start DOS (from a CF), and launch some diagnostic programs and bench.
At the moment it has only one problem, the ODIN chip battery is dead, and it doesn't store the changes in the BIOS, to solve it I should change it or make a modification, to adapt the CR2032 batteries, I will deal with this later.
I already have an update planned, doubling the RAM to 32 MB total, for the moment with the SIMMs I have it's the maximum, but perhaps using a Windows 98 it would be better to reach 64 MB or even 128?
Later I'll try other CPUs, I'm thinking of a 400 or 450 MHz K6, if I want I could also try some Cyrix, but only to do some benching.

A few days ago, I got hold of an ASUS P55T2P4, a socket 7 with HX chipset, the card is working, and currently it is configured with a P.MMX 200MHz and 16MB of Ram (2x8MB 72 pin), later I will update the RAM adding another 16MB, reaching a total of 32MB (4x8MB), unfortunately I don't have four larger modules, to be able to reach 64 or 128 MB or more.
As VGA for the tests I used a SiS PCI, but soon I will change card, a PCI S3 Virge will replace the SiS.
I will also add a sound card, a SB PCI (see photo), I think it will be fine, since I don't have other PCI cards, but in case I need to free up a PCI slot, I could switch to an ISA sound card.
For the moment I would not add other cards, perhaps the only one that could be useful is a PCI LAN, in case I have some aside.

I continued the updates on the ASUS P55T2P4, the video card was changed with the 4MB S3, the RAM went from 16 to 32MB, having added two more identical SIMMs.
For the moment I haven't added a sound card, I haven't decided which one to put, I've added the ASUS MIR card with USB ports, but it needs to be memorized by the BIOS for it to work, and it's not possible because it's necessary to make a change to the ODIN chip, or replace it.
In the meantime, waiting for further upgrades, I tried an ASUS P4S800 with Prescott 3.0GHz, the card works, and soon I'll do some updates, and then I'll do some benches, we'll see what results I get.

I continue with other tested motherboards, the next one I'll try will always be an ASUS, M3N78-EM socket AM2, with 3GB of DDR2 RAM (1GB X3), maybe originally there were four modules, but one got lost, as the CPU doesn't i know which one is there, i'll read from the bios screen the frequency and type, it might be a nice surprise as well, since the motherboard supports CPU up to 140W.
Returning for a moment to the S.7 HX (again Asus), I found a sound card, which I think can be adapted well, a SB PCI ES1371, I have an identical one on a QDI Legend, it should have an Ensoniq chip, and have support both DOS and Windows, good enough?

After a long absence, and due to lack of time, I'm back to writing tests with several MB, unfortunately I temporarily put some motherboards on hold, they just need to be tested, I fixed them by replacing some capacitors, but I have to check if they work.
For the moment I won't write about these, but I'll give a brief summary of the ASUS AM2 visible in the photo placed above, the card starts up and seems to work fine, however it has a big problem, without connected HDs the CPU temperature continues to rise, when exceeds 62-65 degrees, the board shuts down. I tried to see if the dissi was very hot, actually it wasn't, and changing the thermal paste only increased the time (before it shuts down) by a bit.
I don't know if it could be the temperature sensor that is faulty, if so, I don't know where it is, and if it is possible to replace it.
Still on the subject of MB AM2, a few days ago I received an Acer RS780M03A1, with an Athlon 1640, this card will replace the one of my Internet PC with Phenom X3 8650, which has a (frequent) startup problem, perhaps due to a defect of writing data, at the moment I can try replacing the MB and see if it returns ok, in that case there should be a problem in the SATA or somewhere else, since it has not been resolved by changing the hard disk.

I took a look at a motherboard, it's an ASUS Strix (perhaps not very recent), the main problem that prevents it from working are some socket PINs, looking at the visibly misaligned ones, there are at least four very bent PINs, plus some other slightly crooked.
I believe that by being able to put the PINs back in the right position, the card will be functional again (probably), obviously if the failure is only due to the wrong PINs.
Talking to others, it seems it is not that difficult to damage the PINs, perhaps if you are not very careful, by installing the CPU, you risk damaging some PINs, however in the worst case, i.e. breaking a PIN, you can evaluate whether to replace the socket, but I know some replace the single broken PIN.