Hitachi 43FDX01b Looks like Digicon board problem?

[Mike]

Ok I have a Hitachi Projection TV Mod 43FDX01b. That is pulled down
from the top about a foot, and rolled over, and Pulled up from the
bottom about a foot. and it looks like the convergence amp is turned
off. I checked the Vert circuit, and my 26v line is fine, all the
caps in that circuit are fine too. Diodes look good and so do the
transistors.. I know that if there was a problem in the Vert circuit,
like the amp going bad, the HV protect circuit would shut down the
set. but this is not happening. I've seen a lot of problems with the
Digicon board in the past, but I have never seen it couse the picture
to compress like this.

Has anyone else seen this?

I have pulled the Digicon board out and looked for bad solder
connections, but didn't find any, and no bad solder connections on the
main board. Any help on the would be great..

Thanks Michael

 

[David]

Have you ruled out the convergence totally yet?
It is a simple matter to unplug the convergence yokes and see if you get the
standard non-corrected image.

What about the horizontal convergence in the middle, is it still close to
correct?

David

 

[Mike]

Have you ruled out the convergence totally yet?
It is a simple matter to unplug the convergence yokes and see if you get the
standard non-corrected image.

No I'm thinking it has someing to do with the Digicon Board, because
if you were to turn off the Convergence amp ( beleave holding the
convergence setup button in, while turning on the set) thus turning
off the convergence amp The picture looks the same. Like I said the
Top is pulled down and folded over, but the bottom is just pulded up..

What about the horizontal convergence in the middle, is it still close to
correct?

No even in the middle its bowed up above center, and bowed down below
center. just like the convergence amp is turned off..

I beleave the digicon board is the problem, I just never seen it
affect the picture this way before.

I even went to Hitachis Web site to see if there was anything on this
chassy about it, but there was nothing. I would just stick another
one in, but there $274. for another board. even PTS wants $200 to
rebuild one.. So I'm just looking for some comfermation as to the
Digicon bmodule as the problem..

 

[David]

So you still have not ruled out the foldover problem as not being the in the
convergence circuit as you have not unplugged the convergence yokes.

Since the picture looks the same, the convergence could already be turned
off due to it seeing an improper vertical ramp pulse from the vertical
circuit.

Back to basic troubleshooting.
David

 

[Mike]

Ok problem fixed, Vertical Output IC was bad, but it wasn't shorted.
Still not sure what was wrong with the IC, it checked just like the
new one. but I decided to put it in anyway. Got Full screen again..
Looks like the Convergence amps was the only deflection I was seeing.

Thanks for you help David