CurtPalme.com Home Theater Forum

[till]

Hi,

yesterday I turned on my PJ and after some minutes it started to flash and bang inside. I managed to make a video of it:
http://www.youtube.com/watch?v=RieYJ8JT0HE&feature=youtu.be
Seems to be on the focus board, between the resistors R31 and R32, as I found little signs of burning on the solder joints.

first the image shortly dissapears after a flashing, but now it happens so often that there is no picture, and of course I don't want to keep the pj switched on like this.

any hints on how to fix the problem?

[gjaky]

With every arc you take the risk of killing other boards, so don't run the machine in this state.
I think you need to replace the focus board.

[till]

thanks, arc was the word I was looking for


I will try to clean the pj a bit, maybe that will help... it happend out of a sudden, two days before it worked very well and i did not change anything in my setup

[gjaky]

I don't think cleaning would help. When an arc strikes it burns through it's way, and since carbon is quite good conductor the next arc goes on the same way and carbonize the way even more, and the cycle loops, that's why it is arcing more often, you really need to replace the board.

[till]

are you sure that it is only the focus board? and does anyone have a spare one?

[Curt Palme]

You'll need a whole bunch more parts if you keep turning it on.

I've got lots, I need the 762XXX part number off it. Don't turn the set on again until you get a replacement board.

[Curt Palme]

You'll need a whole bunch more parts if you keep turning it on.

I've got lots, I need the 762XXX part number off it. Don't turn the set on again until you get a replacement board.

[till]

okay, will (not) do

the number is 762482

[Curt Palme]

Got it. Shoot me an email to curtpalme@shaw.ca, and we can discuss shipping, etc.

[Curt Palme]

Got it. Shoot me an email to curtpalme@shaw.ca, and we can discuss shipping, etc.

[till]

got it from customs and installed it, the barco works again, thanks.
but i'm not able to adjust the electric focus far enough, is there a master drift control somewhere?

[Curt Palme]

YEs, there's a small trimpot next to the focus block> That should shift the focus. Do you have 07MP or 07MSP tubes?

[Curt Palme]

YEs, there's a small trimpot next to the focus block> That should shift the focus. Do you have 07MP or 07MSP tubes?

[till]

the label is partly hidden, but i think it says 07msp. is it save to adjust the trimpot a little bit and see if it get better or worse?
the service manual says something about measuring 11.9kv, which i would like to avoid if possible

[Curt Palme]

The pot has limited effect, but it should make a difference. No need to measure anything.

That module came right out of my 801 test set. It's possible that you have some leakage in one of the CRT sockets, loading down the focus block. That could be why the old one failed as well. In my test set, the rotation was definitely off to one side, but enough to bring the focus in properly on all tubes.

If it's still off, try pulling off the focus lead one at a time per tube, and see if the other two tubes go into focus. The tube with the missing focus wire connector will be way off the focus point.

[Curt Palme]

The pot has limited effect, but it should make a difference. No need to measure anything.

That module came right out of my 801 test set. It's possible that you have some leakage in one of the CRT sockets, loading down the focus block. That could be why the old one failed as well. In my test set, the rotation was definitely off to one side, but enough to bring the focus in properly on all tubes.

If it's still off, try pulling off the focus lead one at a time per tube, and see if the other two tubes go into focus. The tube with the missing focus wire connector will be way off the focus point.

[till]

found the problem: the one lead plug on the focus board was broken, I now soldered it and it works much better. I will still try to center the focus a little bit, but the image is already much sharper