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Hitachi 32LD7200 - Dead with green light.

 
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bradholland



Joined: 25 Sep 2009
Posts: 1

PostPosted: Fri Sep 25, 2009 2:40 pm    Post subject: Hitachi 32LD7200 - Dead with green light. Reply with quote

Hi there,

Been trying to find out whats wrong with this unit.

Power led goes green on power on.
The remote control is working and can operate the tv, the sound also works.

I get no picture, and no backlight.

Following the service manual

I have tested for >2v on pin 1 of P806 (poweron) when the set is switched on and I have a reading of 0.02V so looks like there is nothing getting there. the service manual then goes on to state the joint or formatter PWB is at fault.

Every couple of tries of turning the set on the screen will turn on for less than a second, lights up and i can make out AV3 flash on the screen obviously telling me what input is selected. This obviously happens very fast if i hold the meter back on pin 1 whilst doing this, i see a momentary reading of voltage.

If i inject 3V onto that pin myself and turn the set on then the screen backlights fine, this leads me to believe the inverter is fine.

is anyone in a position to give me some suggestions to look at? like i said the service manual says that the joint or formatter pwb is at fault. hopefully someone can give me some guesses!!

many thanks,
brad
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Dan the Tv man
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PostPosted: Sat Sep 26, 2009 1:16 am    Post subject: LCd with sound /no pic Reply with quote

Shine a strong flashlight into the screen,if you see a faint picture the inverter boards are bad.Check for bulged capacitors on the inverters.If no pic the main board is bad.The one with the tuner on it.Also the screen panel could be bad.
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minnie



Joined: 18 Aug 2005
Posts: 2880
Location: Hell

PostPosted: Sun Sep 27, 2009 1:59 am    Post subject: Reply with quote

How about jummping the 3 volts with a hard wire/jummper to make it work? Why replace the digital main when you have a work around? The 3 volts should only be present when the set is on.....
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