Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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James Sweet
 
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Default Philips 41JP20 dead

Still have this Philips 41JP20 awaiting my attention, replaced the BUW12A
and HOT but the power supply still doesn't fire up, just makes a faint buzz
then the relay clicks again and the orange and red LED's come on too.
Standby voltage is there, not even a peep out of the other outputs. Any
insight as to why the power supply isn't starting up? I thought I checked
all the semi's but maybe I missed something.


  #2   Report Post  
Jason D.
 
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Default Philips 41JP20 dead

On Fri, 20 Feb 2004 03:07:23 GMT, "James Sweet"
wrote:

Still have this Philips 41JP20 awaiting my attention, replaced the BUW12A
and HOT but the power supply still doesn't fire up, just makes a faint buzz
then the relay clicks again and the orange and red LED's come on too.
Standby voltage is there, not even a peep out of the other outputs. Any
insight as to why the power supply isn't starting up? I thought I checked
all the semi's but maybe I missed something.



What about resistors, caps? This can stop the whole show.
Also philips used neon blue caps, they go bad.

I'm not famillar with this philips chassis, what kind of this SMPS
topology? One for standby only, one for main run power? Or same SMPS
for both standby & run? Or uses regular standby transformer to power
micro in turn trips the SMPS to run when commanded to turn on?

Cheers,

Wizard
  #3   Report Post  
James Sweet
 
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Default Philips 41JP20 dead


"Jason D." wrote in message
...
On Fri, 20 Feb 2004 03:07:23 GMT, "James Sweet"
wrote:

Still have this Philips 41JP20 awaiting my attention, replaced the BUW12A
and HOT but the power supply still doesn't fire up, just makes a faint

buzz
then the relay clicks again and the orange and red LED's come on too.
Standby voltage is there, not even a peep out of the other outputs. Any
insight as to why the power supply isn't starting up? I thought I checked
all the semi's but maybe I missed something.



What about resistors, caps? This can stop the whole show.
Also philips used neon blue caps, they go bad.

I'm not famillar with this philips chassis, what kind of this SMPS
topology? One for standby only, one for main run power? Or same SMPS
for both standby & run? Or uses regular standby transformer to power
micro in turn trips the SMPS to run when commanded to turn on?

Cheers,

Wizard


I thought I checked all the lytics for ESR, replaced a few that were
questionable. It uses a normal 60 hz transformer to provide the standby
voltage.


  #4   Report Post  
Bill Jr
 
Posts: n/a
Default Philips 41JP20 dead

James,
Look for a 100uf 200 volt lytic near the relay and replace it.
Also look for a 300k and 330 k resistor pair in series near the middle of
the board.
You could also be facing a bad flyback.

Good Luck,
Bill Jr


"James Sweet" wrote in message
news:_VgZb.19528$4o.39840@attbi_s52...

"Jason D." wrote in message
...
On Fri, 20 Feb 2004 03:07:23 GMT, "James Sweet"
wrote:

Still have this Philips 41JP20 awaiting my attention, replaced the

BUW12A
and HOT but the power supply still doesn't fire up, just makes a faint

buzz
then the relay clicks again and the orange and red LED's come on too.
Standby voltage is there, not even a peep out of the other outputs. Any
insight as to why the power supply isn't starting up? I thought I

checked
all the semi's but maybe I missed something.



What about resistors, caps? This can stop the whole show.
Also philips used neon blue caps, they go bad.

I'm not famillar with this philips chassis, what kind of this SMPS
topology? One for standby only, one for main run power? Or same SMPS
for both standby & run? Or uses regular standby transformer to power
micro in turn trips the SMPS to run when commanded to turn on?

Cheers,

Wizard


I thought I checked all the lytics for ESR, replaced a few that were
questionable. It uses a normal 60 hz transformer to provide the standby
voltage.





  #5   Report Post  
BWL
 
Posts: n/a
Default Philips 41JP20 dead

I have also seen a bad zener diode cause this; can't remember the location # at
the moment; it's located in the "do not service" area of the P.S.


  #6   Report Post  
James Sweet
 
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Default Philips 41JP20 dead


"Bill Jr" wrote in message
. ..
James,
Look for a 100uf 200 volt lytic near the relay and replace it.
Also look for a 300k and 330 k resistor pair in series near the middle of
the board.
You could also be facing a bad flyback.

Good Luck,
Bill Jr



Got this working finally, the 330k resistor had gone way up in value so I
missed it earlier. Had to pull all three tubes and clean out the coolant
chambers then refill with fresh coolant, cleaned all the optics and put it
back together, the picture looks really good now. Thanks for all the tips.


  #7   Report Post  
Bill Jr
 
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Default Philips 41JP20 dead

James,
Glad to hear that you got it fixed.

Enjoy,
Bill Jr


"James Sweet" wrote in message
newsdb6c.33038$Cb.546243@attbi_s51...

"Bill Jr" wrote in message
. ..
James,
Look for a 100uf 200 volt lytic near the relay and replace it.
Also look for a 300k and 330 k resistor pair in series near the middle

of
the board.
You could also be facing a bad flyback.

Good Luck,
Bill Jr



Got this working finally, the 330k resistor had gone way up in value so I
missed it earlier. Had to pull all three tubes and clean out the coolant
chambers then refill with fresh coolant, cleaned all the optics and put it
back together, the picture looks really good now. Thanks for all the tips.





  #8   Report Post  
James Sweet
 
Posts: n/a
Default Philips 41JP20 dead


"Bill Jr" wrote in message
. com...
James,
Glad to hear that you got it fixed.

Enjoy,
Bill Jr


Now does anybody have a remote for this thing or recommendation for a
universal that operates all functions?


  #9   Report Post  
Bill Jr
 
Posts: n/a
Default Philips 41JP20 dead

James,
Do a search for a Philips PM4S replacement remote.
I found one at Vance-Baldwin for $16.60 plus shipping of course.

Good Luck,
Bill Jr


"James Sweet" wrote in message
news:cqm6c.37122$SR1.43116@attbi_s04...

"Bill Jr" wrote in message
. com...
James,
Glad to hear that you got it fixed.

Enjoy,
Bill Jr


Now does anybody have a remote for this thing or recommendation for a
universal that operates all functions?





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