Monitor erupted in much smoke and loud hissing. Video scrambled but
stayed up. I lunged for the power cord behind it, and unplugged it
within 2 seconds. I took it apart, confident in finding some burst
cap or two. Nothing. Everything on close visual inspection looks
good. No burned traces or bulging/fried components. The board fuse is
OK. I've repaired this monitor twice since new in 2000. A couple caps
in the PS (would't start), and reflowed neck board (video brightness
up/down).
Could a fbt do this, and not show any signs? Something definatly
gassed out violently. It smelled more like burned insulation than the
acrid fried cap smell. I'm not competent to power up the board with
it apart.
JR

Monitor erupted in much smoke and loud hissing.

The odor notwithstanding, the smoke and hissing suggest an outgassing
capacitor.

If that's not it, there /has/ to be some visible problem.

JR North wrote in message
...
Monitor erupted in much smoke and loud hissing. Video scrambled but
stayed up. I lunged for the power cord behind it, and unplugged it
within 2 seconds. I took it apart, confident in finding some burst
cap or two. Nothing. Everything on close visual inspection looks
good. No burned traces or bulging/fried components. The board fuse is
OK. I've repaired this monitor twice since new in 2000. A couple caps
in the PS (would't start), and reflowed neck board (video brightness
up/down).
Could a fbt do this, and not show any signs? Something definatly
gassed out violently. It smelled more like burned insulation than the
acrid fried cap smell. I'm not competent to power up the board with
it apart.
JR



Perhaps the rhinalogical equivalent of the "stethoscope" for tracking down
mechanical squeeks. A drinking straw stuffed in a nostril ? Caps can outgas
at the hidden pin face , not just the "cross-hair" weak spot.

On Sat, 05 Feb 2011 13:35:18 -0800, JR North wrote:

Monitor erupted in much smoke and loud hissing. Video scrambled but
stayed up. I lunged for the power cord behind it, and unplugged it
within 2 seconds. I took it apart, confident in finding some burst cap
or two. Nothing. Everything on close visual inspection looks good. No
burned traces or bulging/fried components. The board fuse is OK. I've
repaired this monitor twice since new in 2000. A couple caps in the PS
(would't start), and reflowed neck board (video brightness up/down).
Could a fbt do this, and not show any signs? Something definatly gassed
out violently. It smelled more like burned insulation than the acrid
fried cap smell. I'm not competent to power up the board with it apart.
JR

Hiss usually = something formerly sealed discharging a gas. Maybe you
missed something in your visual.



--
Live Fast, Die Young and Leave a Pretty Corpse

Found it. C635 10uf 250V bulging slightly on top and tiny trace of
black at the X center.
JR


On Sat, 05 Feb 2011 13:35:18 -0800, JR North
wrote:

Monitor erupted in much smoke and loud hissing. Video scrambled but
stayed up. I lunged for the power cord behind it, and unplugged it
within 2 seconds. I took it apart, confident in finding some burst
cap or two. Nothing. Everything on close visual inspection looks
good. No burned traces or bulging/fried components. The board fuse is
OK. I've repaired this monitor twice since new in 2000. A couple caps
in the PS (would't start), and reflowed neck board (video brightness
up/down).
Could a fbt do this, and not show any signs? Something definatly
gassed out violently. It smelled more like burned insulation than the
acrid fried cap smell. I'm not competent to power up the board with
it apart.
JR

On Sat, 05 Feb 2011 15:47:28 -0800, JR North wrote:

Found it. C635 10uf 250V bulging slightly on top and tiny trace of black
at the X center.
JR

I recently 'baked' a PNY video card to try to reflow some bad solder
joints. Ended up with some electrolytic s that had a black dot over the
X. Replace them and now the card works. It is an NVidia 8500 chipped card
with a BGA GPU. Most of the caps looked ok. I suspect the ones that
dotted were part of the problem. PNY isn't known to use reliable
components since their card was much less expensive than the real NVidia
counterpart.



--
Live Fast, Die Young and Leave a Pretty Corpse

On 02/05/2011 11:35 PM, JR North wrote:
Monitor erupted in much smoke and loud hissing. Video scrambled but
stayed up. I lunged for the power cord behind it, and unplugged it
within 2 seconds. I took it apart, confident in finding some burst
cap or two. Nothing. Everything on close visual inspection looks
good. No burned traces or bulging/fried components. The board fuse is
OK. I've repaired this monitor twice since new in 2000. A couple caps
in the PS (would't start), and reflowed neck board (video brightness
up/down).
Could a fbt do this, and not show any signs? Something definatly
gassed out violently. It smelled more like burned insulation than the
acrid fried cap smell. I'm not competent to power up the board with
it apart.
JR

I've once seen blown fbt which had tiny hole on side. It was hard to see
but obviously there must be either that or some cap. An ESR meter is a
must to find out these almost failed caps, make life much easier.

br
ismo