Fried the caps on old skool 4BDA...

Well - I just decided to upgrade the old battle axe. I have been running a P4 [email protected] in an EPoX 4BDA since March of '02(an eternity it seems like...). This setup has been dead reliable at default voltage, and while the setup was quiet, temps were excellent on all components courtesy of 5 silent 80mm fans all over my slightly modded case. She was an oldie, but never faultered once in 24/7 continuous use for 2 years.

I decided to give the old hoss some more grunt by popping in a retail SL6PC 2.4B and seeing what she could do. I figured I'd hit the limits of the chip before I really ran into a MoBo or RAM limitation, but boy was I wrong.

Basically, plugged her in, 166Mhz FSB for ~3Ghz was a bit unstable at default voltage with the lapped stock HSF(temps maxed at 52*C during P95). Bumped her down to 160Mhz for ~2.9Ghz and upped the VCore to 1.550(+0.025V) since it was dipping alot under load. The voltage regulators were getting a bit warm, but not hot. The northbridge HS was getting quite toasty, but seemed reasonable.

After about 20-25 minutes of torture testing I smelled a whiff of a smell I can only describe as "industrial byproducts" while checking the temps of various voltage regulators and clock gen chips. Upon closer inspection, I saw toasted looking marshmellow goo oozing out of 3 of the larger caps and 2 smaller ones showing signs that they were about to burst. I don't think any other component in my setup would help contribute to this, as I think I put together a solid little system back in the day. The powersupply is an Antec 400W with rock solid 12V and 5V rails, and the Lian Li case has been optimized for the most flow possible while remaining "stock" looking from most angles.



So it appears I hit the limitations in my MoBo's caps before I really got to open the chip up, or even use it...


What are my options? Is it safe to continue using this MoBo at say 2.4Ghz? That honestly leaves a bit of a sour taste in my mouth if I'm resigned to run this chip at 2.4Ghz... a level my 1.6A could hit with a decent dose of voltage(too hot for 24/7 daily grind IMO).

Should I just suck it up and get a newer mobo that won't kill the bank? I guess I'd have to get another stick of 512MB PC3200, and my current stick isn't all that hot(Corsair value PC3200). The key here for recommendations is low cost, not so much eeking out that last bit of performance.

...bah - I knew eventually I'd end up pushing a little too hard with even my tame daily-use OCs, just didn't this mild upgrade would put the nail in the coffin for my MoBo.



Sorry for the length guys, but I'd appreciate any advice you could spare. I guess I could make a spare "entertainment PC" out of my 4BDA+1.6A if I end up buying another MoBo. *sigh* guess my track time habit will have to be put on hold even longer...

There is an option available to you that you may not have concidered. Replace the caps.

It's not that difficult, it's cheap, and you don't have to buy a new board.

All you need is a little coordination, common sense and a soldering pen.

Caps are typicaly around $1.50~ $2.50 a piece.

I recently replaced some on an old Plinta Dually board, and actually I raised the capacitence to handle the o/c.

Look at the caps, you should see that they have some writing down the side ( 1500 µf 6.3V or such). That is the important information.

The µf 1500 = electrical capacity, or how much charge it holds, and 6.3V is obviously the voltage. It is very important that the voltage be the EXACT same, but the capacity can be more (not less), you may actually gain from like doubling your capacity because it will make the volt rail more stable by having more reserve power to draw from.

Also note which is posative and negative side, typicaly the white half of the circle on the board where it is located is the negative side, but check to be sure.

Edit: White half is indicated by black half in the picture....oops

I seggust u don't up the capacidence at all, the system is designed around certain specifications.

Pumping capacitence won't hurt the system at all. It adds a small amount of current draw at start up, but thats it. If it can't handle that little, very brief boost in current draw at boot-up. Then it's pretty weak board. It will only benefit the system. It's adding more of a buffer, which if you understand the physics of how the system operates, is a benefit. TOO much more capacitence could possibley cause trouble somewhere, but it's quite unlikely.

Thanks for the replies guys.


Truthfully, I don't think it's worth it trying to solder on new caps. My soldering isn't exactly what I'd call "precise" given that I rarely practice it, and that seems to be some pretty delicate work. I can definitely see me dealing the death blow with some horrendous soldering job.

Besides - I don't even own a soldering iron or flux etc. etc. So buying all that gets me that much close to a new MoBo that is can probably push this chip higher(I think the 3.0Ghz instability was due to the MoBo, not the chip just by the way it was "behaving").

I'm more wondering if continued use at a lower overclock like say... 2.4Ghz would be possible.

I might start looking for a used/refurb MoBo to replace this one in the future, but my big adversion to doing that is I only have one "decent" stick of 512MB PC3200. Buying another stick kinda makes this a pricey little upgrade.


...though I guess I'll be good to go until PCI-Express, Serial ATA and stuff like that is the norm.

actually, the voltage on the new caps can be higher than what is rated. When I fixed a few of my boards, I used the same capacitance, but usually higher voltage because they were easier to find.

I would recommend using the same capacitance that are on the caps you replaced, simple so any RC time constants aren't messed up. It was engineered to use those, so why not use them

I know nothing about the properties of the caps themselves, but I do know that swapping them out is really pretty easy.

I blew the ones on my 8K3A+ and resurrected it by pulling the good ones out of a dead board I had laying around.

Since then, I have had another sytem start losing some caps- the worst 4 have been replaced, but that's all I had left...
I think I may swing by a store and see if I can find some similar caps myself.