Electronic equipment repair and service manual search discussion :: Topic review

timnpeta · Posted: Thu Nov 26, 2009 4:46 pm Post subject: no sound no power

picked up a free 55fx20b. the owner said it just quit working. i took the back off and lights on the board are green. i do have one red light on in about the middle of the board. if i read things right it is a bad power supply. do i just replace the power supply. if you have an answer you can send me an email to [email protected] thanks

minnie · Posted: Thu Mar 01, 2007 10:42 pm Post subject:

Should still run just no convergence correction.

Guest · Posted: Thu Mar 01, 2007 7:46 am Post subject:

Thanks for clearing that up. So, if the convergence box were to fail, would that only effect the convergence, or would that cause the protection circut to activate and make the TV not fully come on?

I'm trying to confirm that the convergence box is bad, since that's what the previous owner removed. I guess I should re-install it and see exactly what this TV does wrong.

Sorry to the forum regulars, I'm an automotive electronics guy, not a household one. Thanks for your patience! Any help diagnosing this big old beast is greatly appreciated =).

minnie · Posted: Thu Mar 01, 2007 12:05 am Post subject:

It's the DCU. Digital convergence unit. It stores the data to keep the convergence aligned.

cory · Posted: Wed Feb 28, 2007 1:14 pm Post subject:

that box has no relays inside.you will find the relay in the power supply section,little black rectangular part with 12 v on top.usually the contacts burn on them if this is the fault the tv usually does not turn fully off.

Dustn525 · Posted: Wed Feb 28, 2007 12:23 pm Post subject: Hitachi 55FX20B, relay box??

I just got ahold of an 55FX20B Projection TV, manufactured in Aug. '96. The old owner said that a "relay box" needed to be replaced. I haven't a clue if he knew what he was talking about, i don't know if there are any relays in the little metal box that had been taken out of the TV. There are 3 part #s on the unit that has been removed, CS00021, HC2061, and L-6E16-Z. Here's a pic of it:

What does this part do?
What circumstances would cause it to fail?
Can the part itself be diagnosed and repaired...or is replacement the only option?

Also, the owners guide says the the wall plug is the polarized type, but, both of the prongs are the same width. So, I'm afraid to plug the TV in, with the little metal box installed, just to see what it does in the first place. Suggestion?

The last issue, the protective textured cover is scartched and has a couple cracks in it, is this what is also reffered to as the "Supershield"? How hard is it to replace?