CAPs
About 2 weeks after I did the MOSFET swap, the board started acting up. It wouldn't POST when it was warm, it wouldn't reboot, I had to keep it at 100% load (folding @ home) or it would freeze, and eventually I had to lower my overclock.. I thought maybe the PWMIC was giving up the ghost. But no! After some reading, I figured the symptoms were far too much like dieing capacitors instead, even though they looked fine from the outside. So I broke out the soldering iron, and it all started again...
So the search for knowledge on capacitors started, just as it had with MOSFETs. I learnt that ESR (Equivalent Series Resistance) is bad, because higher resistance means it's harder to charge up the cap, and to get charge out of it again. Also, "Ripple" is good, as more ripple means the cap can give out more charge. That's basically all you need to look out for when you're not an electrical engineer.. Oh, and if you want to replace a cap (cool people call 'em caps) go for some that are for equal or higher voltages, otherwise your new (and surprisingly expensive) caps will blow up, and that smells bad!
But Snod, what about that capacitance rating malarkey! WHAT ABOUT THE MICROFARADS!??
Some people may want to shoot me and say I'm talking crap, but honestly, it's not overly important. Capacitance of electrolytic caps varies wildly just depending on temperature, as much as up to 50% either way of the actual rating. The only thing you might get with going with more capacitance is something will trip out because it's trying to charge too much stuff, usually your PSU or the OCP (Over-Current Protection) on your mobo. But I haven't had anything like this happen to me yet.. And the good side is you may well get less droop because there's more charge readily available for the CPU to use. But that won't last for long.. And if you go for less, you
Being the maverick I am, I threw caution to the wind and went with the more is better route. So, more capacitance, and more caps! The original caps are Sanyo DX's rated for 1200uf. I got me some no-name blue things from Maplins (don't go to Maplin for caps, they stock awful stuff like these and Jamicons) rated 2200uf. Yeaahhhhh..
They are like that because I could only fit them onto every other cap on top.. They are soldered in parallel with other ones. It doesn't matter where you put them, because it's all in parallel anyway, so to whatever is connected to them it's just like one massive cap anyway..
Moving onwards, I found an awful PCCHIPS board that was already dead. It was full of 6.3v 2200uf caps though! Mmmmm, G-Luxons too! More caps to avoid if you can.. But who cares, this is just for fun, right?
Here's a shot from the top, you'll see I haven't reaplced anything here except the MOSFETs from the previous thing that happened to this poor board. This time I did it properly and soldered them right down, it works much better as the PCB acts as a heatsink for the FETs, so they run much cooler now than when they were standing up.
Sorry for the small pictures, but it's the only digital camera I had at the time.
Results!
The board lives again! As good as new! 1733MHz was not a problem for it once again, it could boot into Windows and run at 100% load for as long as I liked. That lasted about 2 weeks and then these caps gave up as well, and I was back to the Pentium 2 for the time being..
At this point the board was left alone for a while, but I wasn't finished with it yet...