Hitachi 42pd5200 power board mpf7409 has stopped

[Portishead]

Hi guys,
I need some help finding a fault on my plasma.
The TV turned off last week and now when I turn it on it turns back off in 2 seconds with a click sound. But the green power light stays on.

I have taken the power board out but need help to diagnose the faulty component from some kind people..

Can anyone help me?.

[ReeceyBurger123]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

Have you images of the board please ?

[dick_barton]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

Some good photo's of the back of the set and circuit boards will be helpful for anyone looking to assist you. Nice sharp photo's would be ideal.

[jetadm123]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

There are repair kits available for this power board on both ebay and ohmsupplies (in the UK). Apparently, two resistors and two mosfets fail on this board.

[dick_barton]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

Service manual

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

Yes, I have seen the repair parts. I've tested the mosfets and ceramic blocks. They do appear fine. Don't know where to look next really. Picture as requested.

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

If anyone has any thoughts or ideas please let me.

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

Bump

[dick_barton]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

How about taking some voltage measurements. Do the pins have the voltages they say alongside. Are any voltages missing? All this information helps others help you.

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

Well I dont really know to be honest. I was hoping somebody would be familiar with the set and could direct me.
it's hard to know what to test for when you don't know where to look.

[dick_barton]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

Aren't there any voltages given on the board that you could measure? You picture isn't clear enough to see what is written on the board alongside the connectors. Taking voltage readings are often the first line of action.

[Alastair E]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

You know....?

Ive got a 32" (32PD5200) version of this set in the shop priced at £40....

No One Wants It!--This one even has a reasonable panel in it and fair picture, been there for two months. Only shows the Normal MD these have when stone cold!

Reasons--No HDMI and No Freeview/DTV--Oh--And its SILVER (which appears to be a sin these days, Silver sets!).
Its an Old Dog--Even though in Excellent/perfect condition, complete with speakers....

If you down this way--Come take the thing away--Please!!

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

If it's got an mpf 7409 power board I'll take it!!!

[Alastair E]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

Haven't a clue--but doubt it being 32" not 42" the power demands would be different.

Set worked when received and soak-tested, so didn't do anything to it....

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

How about taking some voltage measurements. Do the pins have the voltages they say alongside. Are any voltages missing? All this information helps others help you.

This does look like the place to test vs / va. Would you agree?
Referencing this and my above image
If you zoom in it says va,vs,gnd.

https://picasaweb.google.com/1178467...eat=directlink

Don't seem to.be able to post pics today on here.

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

How about taking some voltage measurements. Do the pins have the voltages they say alongside. Are any voltages missing? All this information helps others help you.

Ok so testing the pins it gives -
Dc voltage vs as 87.5
Da voltage va as 0

And working my way down the manuals flow chart as linked below it comes out as power supply fault.-

Led is green
Is it in power save mode. (unsure assuming no)????
Cn68 is 5 volt
Cn64 are not correct - pin 1=0v & pin 10 =87.6v (pin 1 should be 50 to 70v
Cn68 pin 1 is 3v

https://picasaweb.google.com/lh/phot...eat=directlink

Any thoughts guys....

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

[Alastair E]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

So--No Va.....

No Va, No Picture....

Investigate Va stage of PSU.

[Portishead]

Re: Hitachi 42pd5200 power board mpf7409 has stopped

So--No Va.....

No Va, No Picture....

Investigate Va stage of PSU.

Can you be a little more specific?? Can you narrow down where to check on my image?