Psu failure taking out CRT ?

  • Thread starter Thread starter dieselmb
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dieselmb

E-Machines are notorious for PSU failures which take down the
mothernoard.
I have one here where the PSU crashed and rendered the MoBo dead.
Inside the PSU there was a capacitor that completely desoldered
itself.
I replaced the PSU, MoBo, CPU and Ram just to find out that the CRT
was dead also.
What I am not certain of is if this is common or coincidence as far as
the CRT goes.
 
Only a signal is sent to CRT, CRT power comes from the mains. Is the
graphics adapter dead too. I'd say coincidence.
 
(Re: No Power to the drives) OP mentioned in a previous thread (02-06-07),
tried splicing into a spare PSU to test the E-machines system board..
Coincidence..?
Cheers
j;-j
 
E-Machines are notorious for PSU failures which take down the
mothernoard.
I have one here where the PSU crashed and rendered the MoBo dead.
Inside the PSU there was a capacitor that completely desoldered
itself.
I replaced the PSU, MoBo, CPU and Ram just to find out that the CRT
was dead also.
What I am not certain of is if this is common or coincidence as far as
the CRT goes.
Click to expand...

I suppose it's possible that if a power surge took out the main system
components, and the CRT was plugged into the same house circuit, that
surge could have taken out both the main system and the CRT.

The only other way I can think of for that to happen would been if a
surge traveled through the video card to the CRT, since that's the
only direct link between the main system and the monitor. However,
that'd probably fry the video card in the process, and you didn't
mention anything about that.
 
E-Machines are notorious for PSU failures which take down the
mothernoard.
I have one here where the PSU crashed and rendered the MoBo dead.
Inside the PSU there was a capacitor that completely desoldered
itself.
I replaced the PSU, MoBo, CPU and Ram just to find out that the CRT
was dead also.
What I am not certain of is if this is common or coincidence as far as
the CRT goes.
Click to expand...

Forget speculation about surges. You have described a power supply
that was missing essential functions. A DC voltage was apparently so
excessive as to damage MoBo, CPU, Ram, etc. That must not happen
using normal power supplies that are required to have overvoltage
protection - as was standard more than 30 years ago. Your power
supply apparently output excessive and destructive voltages that
destroyed ICs everywhere. Therefore excessive voltage may have also
burned out transceivers in the CRT.

How excessive was that DC voltage? Normally a high voltage may only
damage MoBo. Yours was so high as to even damage CPU. The real
question is what was not damaged because power supply did not have
overvoltage protection?
 
E-Machines are notorious for PSU failures which take down the
mothernoard.
I have one here where the PSU crashed and rendered the MoBo dead.
Inside the PSU there was a capacitor that completely desoldered
itself.
Click to expand...

There were ATX PSUs from one of our disties that used to fail in a
similar destructive way:
- often goes BANG when switching on or plugging in
- PSU will rattle when shaken
- the shell of a small electrolytic cap will be loose inside
- mobo, HD will be dead
- optical drive usually dies within a month

The cause was a failure pattern that spiked the +12V line, killing
everything on it. A factor may be excessive current draw when ATX
"off"; the fan's off, but there's still current through the PSU to
heat it up a bit, then when it's turned "on"... POP!
I replaced the PSU, MoBo, CPU and Ram just to find out that the CRT
was dead also.
Click to expand...
What I am not certain of is if this is common or coincidence as far as
the CRT goes.
Click to expand...

Unlikely. The power feed from PC to CRT is just a pass-through of raw
mains, so unless the dying PSU spikes the VGA out, it won't be that.

Far more likely is a mains spike or surge that drilled everything
equally. Are you in a lightening-rixch area? How's your mains?


--------------- ---- --- -- - - - -
Click to expand...
Saws are too hard to use.
Be easier to use!
 
E-Machines are notorious for PSU failures which take down the
mothernoard.
I have one here where the PSU crashed and rendered the MoBo dead.
Inside the PSU there was a capacitor that completely desoldered
itself.
I replaced the PSU, MoBo, CPU and Ram just to find out that the CRT
was dead also.
What I am not certain of is if this is common or coincidence as far as
the CRT goes.
Click to expand...

Wow. I know you can pull quite a bit of current through a vga cable.
(I had one monitor that had a bad habit of biting the hand that
unplugged it. But It lived for at least 10 years, and for all I know
is still alive) I suppose it's possible for a single event to
completely take down a computer system. Given the number of failures,
i'd say it was a pretty impressive surge.

I see the emachines motherboard+power supply failure pretty often.
I've also seen failures of the RAM, and CPU, but never all at once in
the same machine. Have all these components been verified as bad, on
another machine?
 
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