Why my s462 boards posts only with Duron 750?

[LeGrr]

Well, I have several socket 462 boards, 3 of them are Asus, one GigaByte, one MSI etc. Also, I have processors: 2x Duron 750, 2x AthlonXP 2000+ and one Athlon Thunderbird 1200. (Every cpus are tested with good board)

Every board works fine with Durons 750, except Asus A7V8X-x. That board boot only with one of Durons (?!) and works fine and stable. Other processors never post! (I tried every possible combination of various hardware, jumpers, bios reset, flash etc.)

One board, GigaByte, have jumpers for multiplier and bus speed while others are jumperless. When I set that board manually, it posts with every cpu, but not on theirs default settings. Sometimes I can run cpu even faster, for example Athlon 2000+ boots on 11.5x100, 11.5x133, even 11.5x166, but not 12x100! Also, I can run Athlon 2000+ with multiplier 5-7 and 9.5-11.5 but not 7.5-9!

Does anybody knows why socket 462 boards works fine with Duron 750, but not with faster CPUs? I have 8 boards with same behavior! Is it possible that bad caps causes that problem? Is it repairable?

I tried to recap three boards, but results are the same. I am so confused

What should I do?

Thanks!

[kc8adu]

Re: Why my s462 boards posts only with Duron 750?

first make sure those boards officially support the procs you have.
some will only support athlon xp with certain board rev. and bios.

[gdement]

Re: Why my s462 boards posts only with Duron 750?

The 2000+ definitely won't work on everything, it's a newer core that would require an updated BIOS to even POST on older boards. As for the weird missing multipliers, I don't know what causes that but I've heard of it. Isn't that chip supposed to run 133x12.5 (not 12)?
I think there's a compatibility breaking point around 12.5x. They added another bit to the multiplier table and there can be some issues crossing the boundary. I'm vague on the details but multipliers like 7.5-9 might be getting mapped to something else that doesn't work.

But the Tbird 1200MHz ought to work on everything. Unless it's a mixup with bus/multiplier settings. But even if it's a 133mhz bus model it should still be able to run at 100x9 on older boards. If it isn't unlocked then you'll need to have the multiplier correct for it to POST.

It's possible a BIOS flash might fix some things with processors that the old BIOS doesn't fully understand.

If a motherboard is marginally stable, it's possible for it to barely run using a slower processor but not be able to handle something faster. But it's unlikely you're having that same scenario with several boards.

As for the Asus that only works with 1 of your Durons... I have 2 guesses.
1) There's a difference in the stepping of those Durons, causing one of them not to be supported (BIOS flash might fix it)
2) The board is running really badly, and one of the Durons is just more tolerant than the other.
3) Maybe there's something funny with the contacts on the ZIF socket, and/or the CPU pins? Perhaps some corrosion on one of the Durons that the Asus' socket isn't quite able to get through? I know, this is unlikely, but just a guess.

[LeGrr]

Re: Why my s462 boards posts only with Duron 750?

Thank you for replies,

Well, every board is compatible with all processors, some of them worked for years with that processors, especially GigaByte board GA-7VAXP with XP2000+. That board survives power surge about one year before stop posting with XP2000.

Athlon 1200 boots on that GA-7VAXP board at 100MHz bus on automatic multiplier settings, on manual it run on various multipliers, but below 9.

And for Asus that works with only one Duron
I tried almost everything. Detailed washing, treating socket with contact sprays, air blowing etc. I also washed "faulty" Duron. Nothing happens

What part of the motherboard is responsible for cpu recognition?

[stevo1210]

Re: Why my s462 boards posts only with Duron 750?

The part that I think is responsible is the BIOS and the Northbridge though I may be wrong.