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  #1  
Old 07-16-2015, 09:53 PM
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JVC 56P575 no power

JVC 56" rear projection 1080i set plugged in and nothing happening when i push power or attempt to use remote. Can someone point me in the right direction for repair? Not sure if its caps or what. Fuses seem ok.
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Old 07-16-2015, 10:20 PM
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You get no "click" or attempt at power on?

JVC sets were mainly known for losing the convergence amps...not too much more in my experience. This can shut down the set. but you WILL get an attempt at power on.
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Old 07-17-2015, 07:46 AM
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Quote:
Originally Posted by rca2000 View Post
You get no "click" or attempt at power on?

JVC sets were mainly known for losing the convergence amps...not too much more in my experience. This can shut down the set. but you WILL get an attempt at power on.
Not hearing anything at all. Just a quick spark at plug in.
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Old 07-17-2015, 08:20 AM
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Sounds like you don't have your +5V standby supply. This supply is on all the time as long as its plugged in. Diode could be blown as a result of a lightning surge. Or open primary or secondary of the standby supply transformer.
But the last time I saw this it was due to a cracked circuit board interrupting the AC from the standby supply's transformer.
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Old 07-18-2015, 07:30 AM
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Originally Posted by kf4rca View Post
Sounds like you don't have your +5V standby supply. This supply is on all the time as long as its plugged in. Diode could be blown as a result of a lightning surge. Or open primary or secondary of the standby supply transformer.
But the last time I saw this it was due to a cracked circuit board interrupting the AC from the standby supply's transformer.
Sounds like a start. is there a number on this diode? where do i start testing?
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Old 07-18-2015, 08:59 AM
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I would look for a terminal on the PS board that says 5VSBY and see if you have it.
Also remove the PS board (might be difficult) and inspect all the connections. Does the board look like its been hot? Then check for bad caps.
Have you looked around (on this here web) for a pdf schematic?
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Old 07-18-2015, 07:10 PM
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Quote:
Originally Posted by kf4rca View Post
I would look for a terminal on the PS board that says 5VSBY and see if you have it.
Also remove the PS board (might be difficult) and inspect all the connections. Does the board look like its been hot? Then check for bad caps.
Have you looked around (on this here web) for a pdf schematic?
No sign of overheating. Actually very clean. No bulging caps. Cant find the 5VSBY. Nothing out of the ordinary. I'm lost
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Old 07-19-2015, 07:44 AM
kf4rca kf4rca is offline
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Next step...

Put the PS board back in, turn it on, and probe around with a DVM to see if you have ANY voltages on it.
Be careful cause an inadvertant short can send the whole thing up in smoke.
Might be conv board but you would most likely get a distorted picture first.
I'd also sniff around for any unusual burnt smell.
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Old 07-19-2015, 08:07 AM
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Get a couple of GOOD pictures of the boards...good enough for me to be able to follow things and I will try and tell you what to look for .
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Old 07-19-2015, 08:13 AM
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Get a couple of GOOD pictures of the boards...good enough for me to be able to follow things and I will try and tell you what to look for .
Will do. Just gonna take me awhile.
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Old 07-20-2015, 07:07 AM
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Let's back up.

Whats the power LED doing? Is it on, off, or blinking (count the blinks).
It could actually be working. Try feeding an external audio signal into it. Do you get sound on the speakers?
A possibility exists that the CRT is in "protect" due to scan failure (either H or V).
My guess is the vertical has died. Pull the deflection board and sniff for burnt smell. The vertical chip might have a TDAxxxx number on it. I always thought they had inadequate heat sinking on these.
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Old 07-20-2015, 07:50 AM
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Quote:
Originally Posted by kf4rca View Post
Whats the power LED doing? Is it on, off, or blinking (count the blinks).
It could actually be working. Try feeding an external audio signal into it. Do you get sound on the speakers?
A possibility exists that the CRT is in "protect" due to scan failure (either H or V).
My guess is the vertical has died. Pull the deflection board and sniff for burnt smell. The vertical chip might have a TDAxxxx number on it. I always thought they had inadequate heat sinking on these.
No led, no sounds. Its as if it was not even plugged in. I dont even know where the led is on this set.
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Old 07-20-2015, 08:16 AM
kf4rca kf4rca is offline
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Wow!

You have a power problem! Check continuity of the line cord. This might be an easier fix than I thought!
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  #14  
Old 07-20-2015, 08:40 AM
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Originally Posted by kf4rca View Post
You have a power problem! Check continuity of the line cord. This might be an easier fix than I thought!
I'll test and let you know. Could possibly be a break somewhere in the line.
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Old 07-20-2015, 07:33 PM
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Tested and getting 119.1 where the cord hits the board.

Last edited by pac.attack76; 07-14-2016 at 02:47 PM.
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