Can Blown Cap's Cause CPU damage?

[ImWolf]

Once again I have extracted the MB from my office machine to replace 2 blown capacitors. These are 2 of the last surviving original cap's and are located close to the CPU socket. An online search as to what these capacitors function is was fruitless.

I was first alerted to a problem while booting into Linux when the final string of error messages reported something like "Kernel not syncing with CPU". Following this I was able to boot into XP one more time, but not Linux. Eventually the machine wouldn't boot into XP either. No error messages or BSOD... just a sudden shut down shortly into the boot cycle. It was then that I opened the case and saw the 2 very blown caps.

In the past this machine had a different MB which had some blown caps, but as I recall it was still working fine for quite a while until more of them blew and a repair was needed. So, I'm not sure if the current blown caps happened 3 days ago which led to the boot problems, or if they were already blown for a while and I just wasn't aware of it yet. (it's been about 80° in my back office lately, which is warmer than usual.) The 3 cooling fans, the CPU fan, and the PSU fan are all working.

After I pulled the CPU to check the pins and socket for any visible damage, I saw nothing obvious. But that won't really be definitive as to weather or not the CPU might have been damaged? I have 2 more identical CPU's I trust are in working condition.

So this leads me to my question: Should I replace the CPU along with the caps? If I take this route and everything works again, I'll never know if the current CPU is damaged. On the other hand, if I just replace the caps and the machine still won't boot, then I'm looking at another (at least partial) tear down to replace the CPU later.

These AMD Athlon 64 x2 6000 CPU's are listred at between $30 and $65 on evilbay, so it's not a huge expense to just declare it DEAD without knowing for sure. However, my inquiring mind would rather know if it truly is garbage now.

Which option would you take?

(Old photo's were taken prior to previous re-cap. The current blown caps are circled in yellow.)

Thanks,
Wolf

 

[Chiron]

Most likely (99%) those two defunct capacitors won't harm the CPU, although their being dead may and probably will affect its performances.
Hard to say without a detailed schematic (as easily available as a complete map of Hell), but generally those large electrolytic capacitors are mounted between GND and a power track (+3.3V) to buffer it during short power drain surges.
After so many years they usually croak open -- even if there's some tiny short circuit left, it's soon blown away by the huge amount of power available at the terminals.
Thus all in all I would try and replace them without fearing for the new CPU -- nor for the current one, which is probably still OK.

Two points that you probably already know all too well (but better safe than sorry):

- Desoldering anything on a 6+ layers motherboard is a PITA even with the help of a professional hot plate. It's much easier (though aesthetically hideous, but who cares?) to cut off the deceased ones leaving a bit of leg protruding and solder the replacement there. Even that will require a fairly sturdy soldering iron.

- DOUBLE-CHECK THE POLARITY! Mismounted electrolytic capacitors kick the bucket a few milliseconds after power on.

Good luck!

 

[ImWolf]

Two points that you probably already know all too well (but better safe than sorry):

- Desoldering anything on a 6+ layers motherboard is a PITA....

Swapped out the capacitors last night, and I can't argue with you on that task often resulting in foul language galore. However, this event was not so bad. When I finally got the board isolated and looked at the back side, these caps had obviously been replaced once b4. The soldering was too nice to be any of my work, but surely not factory quality either. Also, who ever did this had used the same spec caps as the originals. It turned out to be the easiest de-solder / clear hole I've done to date.

I did use the same CPU and 12 hours later there's no sign of any problems.

 

[cleverscreenname]

evilbay I am so stealing that. That's how I feel, it sucks in so many ways, but it still feels less evil than Amazon. I see on evilbay for $49.95 you can get a socket AM1 motherboard, plus 8gb DDR3, plus AMD 5350 quad core, and being APU it has Radeon HD 8400 built-in. You would cut your electricity usage by at least half, almost double your speed (2 generations newer architecture) and gain SSE4. It has drivers for XP (including XP64) up through win10.

Did you already see TMTGTR's attempt at this? https://www.xpforums.com/threads/re-capping-a-motherboard.934656/