MORE UPDATE: Dell Optiplex SX260 Computer Won't Boot Up

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Hi,

More Update:

I replaced every one of those 2200/6.3V with new Nichicon 2200uf 10V
105 deg. caps (verified good by testing them), but that did not fix the
problem. The symptoms are exactly the same as I described in my original
post. Note: I also replaced some other caps that had higher than normal ESR
(eg. 220uf 16V caps).

Note: I measured in circuit the +5V and +12V voltage sources, and both
were "clean" (scoped) and at the proper level.

Without a schematic, there isn't much more I can do. I have decided to
abandon this repair attempt.

John

 

[Jamie]

Hi,

More Update:

I replaced every one of those 2200/6.3V with new Nichicon 2200uf 10V
105 deg. caps (verified good by testing them), but that did not fix the
problem. The symptoms are exactly the same as I described in my original
post. Note: I also replaced some other caps that had higher than normal ESR
(eg. 220uf 16V caps).

Note: I measured in circuit the +5V and +12V voltage sources, and both
were "clean" (scoped) and at the proper level.

Without a schematic, there isn't much more I can do. I have decided to
abandon this repair attempt.

John

how about the 3.3V ? How About the - voltages from the supply?

How about removing some cards like the video card to see if it'll post?

How about checking the actual on button on the cabinet?

Unplug the HD to see if you get a post ?

Have you removed memory chips?

lots to look at..

There is always that possibility you have a bad MB.....................
like Flash rom bad ( no bios) CPU is dead from over heating, small
onboard processor not work etc....

Etc...