Depends on which type your 533 Celeron is. Only the PPGA Mendocino version will likely run on your ECS board. You can find the details here and there are photos when you scroll down:
http://www.cpu-world.com/sspec/SL/SL3FZ.html

The later version is FCPGA Coppermine with green plastic and that will most likely not run.

[edit] see attached manual

Hang on... if the Super I/O chip is short-circuiting, you have bigger problems than an incompatible CPU.

In any event this is the i440EX chipset, so max 66MHz FSB in-spec and if you're lucky 83MHz OC. Also max 512MB RAM in total (or rather: 2 double-sided DIMMs, or 1 double+2 single-sided - if the chips are less than 128Mb, capacity will be similarly less).

In any event, it will be a PPGA socket. You can mod it to FC-PGA (Coppermine), but then you still need to do something about voltages and BIOS. Basically this is the archetypical Mendocino Celeron board.

@dionb
Just to clarify the faulty SIO is on another motherboard I got last week (actually got a complete white PC tower in nice condition), I am sure that is a P3 533 though i don't know which type because I didn't remove the heatsink from the CPU yet. There is a sticker on the back of the tower with the spec printed on it which says PIII 533 so that will be what it is because the rest of the spec seems to match the sticker. I don't recall which motherboard it is either but it's an unusual looking one. It is a mini ATX board, has 3x PCI and what I thought was an 1x AGP until I realised it had a modem card plugged into the rear half of it and it's like 2 smaller brown CNR type connectors in line with each other. I will post some pics of that tomorrow as I have not seen such a thing before.

When i say the SIO is short, actually the PC will not start up at all (the ATX PSU does not get the turn on signal even though I have 5V on the start button pin. If i force the PSU on then I get 0000 on my post test card. I worked out it is the SIO which is faulty because the CMOS battery was completely flat like 0.02V which is unusual. So I used my bench PSU to supply 3.2V to the battery connector and checked with my multimeter on uA range to see how much current it was drawing. A good SIO normally draws about 1-3uA when the motherboard is powered off. This one goes to OL on the 200uA range. I don't have the correct variant SIO chip (W83627F-AW) in stock so I have ordered some.

So in the meantime I was wondering if I can use that CPU to test this motherboard, as I don't have any other Socket 370 CPU in my stash of goodies. I guess from the replies, this will depend on exactly what the CPU is. I think it is the green type with a glass die in the middle.

Fastest celeron you can run in that is 433. thats also probably the fastest cpu that will run without some kind of mods or adapters.

Your board is 66mhz
http://www.cpu-world.com/CPUs/Celeron/I ... 0128).html

Also here is bios.
https://web.archive.org/web/20100106152 ... 82&LanID=0

Cheers
I can get a working P3 433 SL3BA CPU inc postage for less than 10 euros.

Rich

edit
I've ordered one.

As far as I understand it any Celeron with CPUID 0665h will work in motherboards like that ECS:

sSpec // stepping // cache // CPUID // freq // package
SL35Q // B0 // 128 // 0665h // 300A/66 // PPGA
SL36A // B0 // 128 // 0665h // 300A/66 // PPGA
SL35R // B0 // 128 // 0665h // 333/66 // PPGA
SL36B // B0 // 128 // 0665h // 333/66 // PPGA
SL36C // B0 // 128 // 0665h // 366/66 // PPGA
SL35S // B0 // 128 // 0665h // 366/66 // PPGA
SL3A2 // B0 // 128 // 0665h // 400/66 // PPGA
SL37X // B0 // 128 // 0665h // 400/66 // PPGA
SL3BA // B0 // 128 // 0665h // 433/66 // PPGA
SL3BS // B0 // 128 // 0665h // 433/66 // PPGA
SL3EH // B0 // 128 // 0665h // 466/66 // PPGA
SL3FL // B0 // 128 // 0665h // 466/66 // PPGA
SL3FY // B0 // 128 // 0665h // 500/66 // PPGA
SL3LQ // B0 // 128 // 0665h // 500/66 // PPGA
SL3FZ // B0 // 128 // 0665h // 533/66 // PPGA
SL3PZ // B0 // 128 // 0665h // 533/66 // PPGA

Yes. No idea where the "433MHz max" came from, this is a Mendocino PPGA board and Mendocino goes up to 533Mhz.

NO worries - I only want the P3 433 for test purposes anyway. I am trying to build a collection of processors so I can test any boards I come across, and when I find I don't have the right type of CPU I buy one to add t o my collection. AS they are only for test usage I tend to get the cheapest processor I can find that fits that socket type. Anything under 10 euros it's not even worth trying to find the cheapest option.

I had a look at the other P3 board I found last week. it's a P3 733 CPU which is currently untested. However due to the motherboard having a faulty SIO the CPU is probably OK (I doubt there were two faults) and a lot of stuff I find at the flea market is actually working (whole PCs)

This is the motherboard that has that weird slot on it. The motherboard manual says it is an AMR and a PTI slot. I never saw one before. It also says this is a Micro ATX WH5 motherboard. What does that mean?

See pics.

dicky96 wrote on 2020-01-20, 15:45:

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I had a look at the other P3 board I found last week. it's a P3 733 CPU which is currently untested. However due to the motherboard having a faulty SIO the CPU is probably OK (I doubt there were two faults) and a lot of stuff I find at the flea market is actually working (whole PCs)

This is the motherboard that has that weird slot on it. The motherboard manual says it is an AMR and a PTI slot. I never saw one before. It also says this is a Micro ATX WH5 motherboard. What does that mean?

See pics.

No idea what the "WH5" means. It looks like an MSI MS-6178 to me, which is uATX all right. Also complete i810-crap, so if it is dead, not a major loss.

Yeah it is an MSI and 6178 sounds about right though I'm not at the workshop now to check. It has a faulty SIO. I've ordered some of the correct type. I am fixing as many motherboards as I can get my hands on at the moment as I am teaching myself how to repair them, from 486 boards to Z390 gaming boards.

The cost of the parts are worth it to me in the experience gained and any I do fix I either keep as test boards for a certain socket type or RAM type or sell to then buy more stuff to fix and test gear to fix them with .