Re: Does humidity effect bad cap symptoms?

Just an update from the bad cap computer no less.

It looks like I fixed it - God willing. Remember I said a hair drier to the power supply would bring the computer up on cold days. Well it occurred to me that with electronics when symptoms change because of temperature it is usually a mechanical connection problem. So I took the power supply out and disassembled it so I can see the solder side of the main pcb. Well I noticed that a small daughter board had some heat discoloration near the edge. I got the old eye loop out...

Re: Does humidity effect bad cap symptoms?

I have some more info on this failure. Since it's intermittent I thought I would try an old but effective tool - the hair dryer. I first tried heating up the area of that bad cap in the picture - no change. I next tried the area of the expansion cards - no improvement. I eventually found out if I blow hot air into the power supply for about 3 minutes and then turn it on the machine comes up. So whatever is wrong likely has to do with the power supply. I need to find one I can swap in temporarily to confirm my theory.

Re: Does humidity effect bad cap symptoms?

Gianni

Thanks for the reply. There is HN(M) on the cap as well as H0428. Lots of Nichicon caps but also Rubycons. Managed to get a better pic of the cap....

I have a Dell 8400 purchased new in October of 2004. Recently it started to shut down sometimes during POST and sometimes while the OS is loading. Usually cycling the power a few times brings it up and fully functioning. Once there it will work fine for as long as I like. Yesterday we had an unusually humid storm come through here and I could not get the machine to come up at all. Today we are much drier and the machine took it's normal 3 times power cycling and came up. Has any one else noticed a humidity and/or temperature factor in the bad cap symptoms or a bad power supply?

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