Warning about BX6-R2 and faster CPUs!

I recently owned an Abit BX6-R2 and was running a C2 600@900. I noticed a few times in the past that when I would play with the voltage settings, with the QR BIOS, that the default setting would change to 3.45 volts. I don't remember this happening with my previous CPUs (533@800 and 566@850) and really didn't think too much about it, since I was using a User Defined voltage setting, anyway.

Anyways, recently I bought a C2 900 and in the process of installing it, I did what I always do. Went into the Soft-menu and reset all of the CPU settings to default, so I could avoid having to use the Insert key to clear the CMOS. I noticed that the voltage had reverted to 3.45 again, but didn't think too much about it. I guess I was thinking that when I saved and exited, the BIOS would read the voltage from the CPU and adjust accordingly.

Boy, was I wrong. The reboot resulted in a fried CPU and a useless motherboard with a fried Mofset module, whatever that might be. Also, like a damned fool, I decided to see if the CPU was really fried on another BX6-R2 that I had. Bad move, guess what, another dead motherboard.

Anyway, there's two things to remember here, never test a dead CPU on a motherboard you care about, and "ALWAYS" specify a User Defined voltage, even if it's the CPU's defaut, on larger CPUs on these boards.

I'm not sure if this happened because the board had no native support for a 900mhz CPU and simply didn't know what it was dealing with or if it was something I might have done, but I do know I ate a bunch of equipment in one fell swoop via my stupidity.

I hope this helps someone else avoid my mistakes!

Rick

are you sure you are talking about the Vcore?
and not the IO voltage? as abit boards often set the IO voltage upto 3.5 by defualt.......
The celeron doesnt even alow a setting of 3.45 volts....
the max it will tell the motherboard to do is 2.3V and that is with a voltage hack.

Or maby you just had a bad board... and that is odd... i've never had any problems like that at all with ABIT boards before in the past.

Sounds like something is not jumpered right on the board. Those older transitional boards tried to cover everything with one board and you had to know exactly what you were working with. The ram voltage had jumps IO jumpers etc. Please use the manual before applying voltage when using older boards.

Nope, had the board for 3 years prior and never any problems before I caused this. No jumpers on this board, strictly driven from softmenu. Only jumper there is the clear CMOS. And, yes it was the core voltage, IO voltage was just fine. I know that no CPUs can use 3.45v, but by gosh these boards will certainly give it to them if you're careless enough, as I was, to give it to them. BTW, this is something with the board or the QR BIOS not having native support for 900mhz CPUs, because both of the boards I had would do it. Alls I'm saying is to be sure and use a user defined voltage with Celeron CPUs over 600mhz.

Rick

Dude....did you have jumpers on the slotket set correctly??

Either your power supply is screwed or your slotket was screwed or you somehow got a bad mobo or cpu. I've been running with latest bios a slot1 300a@450 and now a 700@933 for years. These boards just rock, sorry for your loss dude.

ps: Process of elimination points to the common denominator between both boards you fried. If it was the mobo your second one would not have fried.

Both of these boards had been running C2 600s @900, mounted on MSI 6905 slokets set at defaut, since Nov 2000, with absolutely no problems, whatsoever. The only common denominator here was that when I would set the CPU voltage in Softmenu to default, it would default to 3.45v. Never rebooted with that setting before this incident, always manually set it back to 1.7v. Forgot/failed to do that this time and the results were catistrophic. The second board got fried only because I stupidly decided to test the fried CPU on it. I'm trying to remember, but before these last two CPUs that were 600 cCO stepped, I had two that were cBO stepped that had a lower default voltage and I don't believe they exhibited this behavior. Maybe it had something to do with that and the motherboard BIOS not being able to identify the cCO chips, not really sure.

I don't own the boards any longer, so it's not really a problem for me, although I do miss them. Both performed flawlessly for at least 3 years before this happened. Just trying to save someone else from suffering similar greif.

Rick

3.45v? Well, there is your problem right there.

You said that your C2-600s defaulted to 3.45v right?
Doesn't something ring a bell here?

Where else have you ever seen 3.45v as default voltage ? Does CYRIX bring back any memories?

There are two possibilities here.
1) Your slotket is jumpered for Cyrix cpu's somehow---or you jumpered the slotket improperly.

2) You are using a 1.x revision of the slotket which does not support coppermine cpus. Some have successfully used these slotkets on the coppermines, when you are SUPPOSED to use the 2.x versions.

So, I wouldnt blame the mobo at all here. Did you double check the slotket version AND the jumper settings?

Falkentyne, o' knowledgeable one who does not read. If you did, you would realize that the slotket was set absolutely correctly and that nothing, including a setting for a Cyrux 3, should, or would give a core voltage of 3.45. This thread was only intended to make others aware of a possible problem with these boards and certain CPUs. Everyone who has responded seems to think I need some advice or a solution. I don't, any more, unfortunately, but I can assure you and anyone else who wonders, that everything here was setup correctly and worked extremely well for a long time. I was aware of this problem on both boards with both CPUs well before I made my mistake, however I did make it. Irregardless of all the fine advice that's been given, I'd be willing to bet that if you have an Abit BX6-R2, running the QR BIOS, using an MSI 6905 Slotket(everything set to default or auto), with a C2 600 overclocked to 900, and set your voltage to default in the softmenu, that it will adjust it to 3.45v. I'm, also, absolutely positive that if you save and exit with that setting, you'll be just as sad as I was. Thanks for all the advice and theories, but I don't really need them any more, but I do appreciate the thoughts.

Rick

I'd double check for ya, but alas....I only have a Cellie 566........