What cap mfr. to use?

I guess that would be a rather serious problem if the temperature inside your computer case averaged 105°C = 221°F.

In article , Spehro Pefhany writes

Seen a modern mainboard recently? Voltage regulation MOSFETs with heatsinks on, some with their own extractor fans? Heat coupled to the capacitors by a few millimetres of thick copper PCB trace for excellent heat conduction?

But isn't that at "high" temperatures, or some other extreme operating condition?

Certainly.

Have you put a thermocouple on the capacitors?

AT RATED TEMP and RATED RIPPLE CURRENT. Rarely found in combination except by bad design, and it does happen sometimes.

You can get far better by de-rating. Rule of thumb is to reduce the temp from rated value by 10C and double the lifetime etc etc.

Graham

Yes.

Grham

Point 1: You can ventilate your case and CPU far better than 'normal' methods.

Point 2: leave the side panels off like I tend to do !

Graham

You need a themocouple and a suitable meter for that ! ;~)

Graham

S*it, I'd generally be happy with 2000 hours MTBF.

I do, but that's mostly to make it easy to perform full backups. The machine run coolers, though it spews more RF, which keeps atomic clocks in the same room from synching.

By the way, check the CPU cooler occasionally. Mine hadn't been cleaned since I bought the computer over eight years ago, and you cannot believe how clogged with shmutz the heat sink was.

Not a problem for me.

I clean them moderately regularly. Plus I don't operate in a very dusty environment.

Gragam

Nor do I. This wasn't dust -- it was more like gobs of sub-microscopic carbon particles.

Never seen that. On the CPU cooler itself you mean ?

Grham

Yes ! Gigabyte got bitten hard by that and the fake motherboard scam.

Really? ;-)

Of course many, if not most, portable multimeters have type K thermocouple inputs (of dubious accuracy, but good enough for this sort of thing) and many are supplied with a bead thermocouple.

Less than 12 weeks? You have a bright potential future with Samsung, HP etc.

Funnily enough, often some of the cheapest ones have the thermocouple input but I used to keep a supply of type-K themocoouples anyway. I like keeping an eye on temps.

Graham

On the heat-sink. It reminded me of the black stuff that comes off a CRT faceplate. Only a lot more.

On May 7, 6:53=A0am, DaveC wrote: > Today I ordered electrolytic caps. It was frustrating. I had planned to get > the best low-ESR replacements for all the caps in some switching power > supplies. I discovered how limited any one manufacturer's low-ESR catalog is. > Many of what I needed (none of which seem to me to be esoteric values) were > not available. A couple of times I had to leave a particular manufacturer's > catalog altogether to find a value. >

I buy the replacement parts at a Hollywood dub house. Last year I bought 14.000 'lytics , 10,000 installed by 3 of us. My first choice in Panasonic FM but the selection isn't as wide as the second choice of FC caps. If I run into a physical size problem Nichicon PW series often helps. For surface mount first choice is Panasonic FK and sometimes HC series. If you're doing this a lot like we are, Metcal soldering irons are HIGHLY recommended. The STTC-126 tip (700 F 30 degree bent tip) is really good for clearing stubborn holes - usually ground planes with lousy thermal reliefs. A lifted pad is a very rare event with a good soldering iron.

G=B2