HP dc7700 with bad Chemicon KZJ

[pfrcom]

dc7700 wouldn't power up, so I had a look under its cover to find these two:

[pfrcom]

Re: HP dc7700 with bad Chemicon KZJ

Replaced with a pair of Panasonic FJ salvaged from a deceased board, now dc7700 works fine

[c_hegge]

Re: HP dc7700 with bad Chemicon KZJ

Nice. I'd replace the other 3rd KZJ in the top right of the pics there too, though.

[Topcat]

Re: HP dc7700 with bad Chemicon KZJ

They typically have a bunch of KZG 1000uF 6.3v, repalce those as well. They have UCC sometimes, MBZ sometime, and panasonic sometimes...or a mixture of all the above. I have a corporate client that sends me dozens of those at a time because of failed UCC caps. Oddly enough, the 1800uF 16v are almost never failed, its always the 1000uF's....

[pfrcom]

Re: HP dc7700 with bad Chemicon KZJ

This one was unusual - its case fan was working, blowing air across those KZJ and into the heatsink

And the heatsink fan was fine too, pulling air from the other side of the heatsink

Its various KZG, and others, looked OK as well

I've just completed re-imaging and rollout of seventy dc7700, having problems with only two

The other one was extremely clogged around those two fans, and everywhere else - after I cleaned it up, found one bulging 1000uf 6.3v KZG

Not that I looked under each one's cover - if it powered on and passed a quick disk check from manufacturer's diagnostic, it got re-imaged and moved on

They're not my machines - didn't like to see a perfectly good system discarded for the sake of a little TLC, although enthusiasm and love jobs do have their limits

[kc8adu]

Re: HP dc7700 with bad Chemicon KZJ

vrm inputs.
maybe symptom of a power supply cap issue?
or just kzj being kzj.