Hitachi 42PD6600

[Paul Matthews]

Hi all,
Just received one of the above plasmas with the usual "no power" fault. Found R003 and Q201 faulty so replaced both resistors and the 2 commonly faulty transistors (R003, R005, Q201 and Q220) but as soon as I plugged it in R003 went pop again. Checked transistors again and found Q201 had shorted. Had a bit of a dig around the psu board and found another transistor Q101 also shorted so this time I replaced that one too. Plugged back in and same thing happened. At this point I got fed up of soldering and bought another board.

Fitted the new board today and unit powers up, however it gives no picture or sound and remote appears to do nothing but the backlight is on. LED on front of unit is green from power up and stays that way. My guess is that the first faulty psu has taken something out on the main board or that the replacement psu is faulty and not giving a 12V output. I've gone over the main board but can't see anything that seems to be a fuse and whilst I have tested and found I have no 12V output from the psu I'm not sure I would have if the main board wasn't "requesting" it.

Any help to point me in the right direction would be much appreciated.

Thanks, Paul

[Caleb]

Re: Hitachi 42PD6600

if the panel is primed it is most likely going to be main board, control board, or the power supply. Pictures are always helpful. most control boards have test points you can short to display test patterns that would prove the main board at fault. Tom66 might be able to circle them for you if you upload a nice sharp picture of the boards.

[Paul Matthews]

Re: Hitachi 42PD6600

Thanks for the reply. I know I should be putting up pics but I don't have a camera capable of getting a clear enough pic. Unfortunately this tv isn't worth investing much more money in so I'm reluctant to buy a camera just for this. I'll see if I can borrow one in the next day or two and get some pics up. When you refer to the control board would that be what is also known as the logic board? I'm convinced there must be something that can "blow" on the main board to protect the circuitry on there but I can't see what. I'm used to fuses being labelled with a component I.d. Starting X or Z but the only ones on this board with that notation are caps (the X's) or audio filters (the Z's). There are loads of what look like 0 ohm resistor denoted with the letter S, could these be some sort of protection? Having said that I'm sure -kve checked them all and they all show continuity. Have also checked transistor on Xsus and none seem shorted. (I only have a multimeter to test with). Anyway, I'll try to get pics up but if anyone can give experience of this issue and the cause then please do. The Mrs wants the kitchen table back!

[Caleb]

Re: Hitachi 42PD6600

You have a glow when it comes on correct? that pretty much tells you that the y, z and power are functioning. if you had sound I would say that the control (logic) board would be my first suspect, as you dont I would lean towards a failed main, But Ive never had a hitachi in my shop to play with and Ive heard they are a pain to diagnose and impossible to find schematics for. most smart phones can take pretty sharp pictures up close. I found a pic of the control on Shop Jimmy and they have lots in stock and are out of the Vestel built main board ( I can already hear Tom extolling the poor quality of Vestel) I dont see any test points on the control maybe Tom can point them out? I also see Akai, Phillips and lg made tvs using this panel, not sure if you could swap in one of their main boards and get it to work

Just curious if you inject 12v into that harness if the main would function correctly? according to the manual the 12v is for the 60v va regulation. and since your panel lights that in theory should be working?

Not sure if you have the "service manual" for this set? I attached below.