View Single Post
  #42   Report Post  
Posted to sci.electronics.repair
Jeff Liebermann Jeff Liebermann is offline
external usenet poster
 
Posts: 4,045
Default Golden Rules of Troubleshooting

On Wed, 16 Dec 2015 11:34:43 -0800, (Dave
Platt) wrote:

In article ,
Jeff Liebermann wrote:

However, it also helps to pay attention. Do you see a problem here?
http://802.11junk.com/jeffl/crud/GX520-bad-caps.jpg


A blue one with a headache.


The "bad-caps" is in the URL, so that's rather obvious. However,
that's the result, not the problem. The cause is quite obvious once
you see it. I posted the picture previously and Phil Allison caught
the problem almost instantly. I didn't.


Are *all* *four* of those large caps installed backwards?!?


Yep. When I do something wrong, I'm consistent. As I previously
ranted, when I find one bad cap of a type and value, I replace *ALL*
the caps of the same type and value. My time is more expensive than
the extra caps.

Yah. Amazing you didn't have a chassis full of oily linguine there.


Actually, the machine ran quite nicely for a day or two the first time
I put the caps in backwards. Eventually, it started acting strangely
so I retreived it from the customers. All 4 caps were bulging. So, I
replaced all 4 caps again, putting them in backwards again. That's
when I noticed that they were getting hot, which prompted my initial
Usenet posting. I too would have expected at least a small explosion,
but nothing happened.

--
Jeff Liebermann

150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558