Electrolytic Capacitors--Problem on Amiga Circuit Boards?

[Noster]

Hi

The capacitors-problem seems to be a problem of the modern very hot running PeeCee Motherboards with the CPU's that require much power. :-D
I have a couple of old Amiga computers -- from A1000 upto A3000T -- and my 12 years old A3000T runs several hours every day without any problem in the last 12 years (except a defective 8520 and a renewed battery).

The german C'T computer-magazin has reported a few times about these capacitor-problem. It seems that there is at least one charge of a few millions of capacitors produced with bad electrolyt. When these capacitors work in a very hot environment they burst in less than 1000 hours of usage instead of 10 or more thousend.

Noster

[Noster]

Hi

@nOw2

>  have run the machine rather warm (it spent last summer with the case temperature at 50C+...

That is very hot, you should add an additional fan to cool your case down! Intel recommends case temperatures below 45C and AMD below 40C, otherwise the CPU cooler cannot cool your CPU good enough, it may overheat.

Unfortunately there is no known maximum case temperature specified for the Amiga, but I think many problems with the CyberstormPPC cards are temperature problems, either a defective CPU-fan, a case that is too hot or maybe bad capacitors.
I have replaced the CPU-fan by a 12V 486'CPU-fan, and added two more fans in my A3000T case to cool it down. It has previously reached 50C an more in the sommer at a room temperature around 26C. Now it stays below 40C :-D.

@everybody

Have a look at your capacitors. Usually there is a temperature printed on them. There are two mayor types a 110C type and a 80C type (I think). The capacitors are specified to work 2000(!) hours by these temperatures (not a long time-period in my thought, but they work longer if these temperatures are not reached). If they have a bad electrolyt inside and the manufacturer build in the cheap 80C type and the system is running hot (as the system of nOw2) and a couple of hours every day, these capacitors can blast within one year :-(
Especially if you look where these capacitors are usually mounted: Direct in the hot air blown from the CPU cooler.

Noster