CurtPalme.com Home Theater Forum

deronmoped · Joined: 03 Nov 2006 Posts: 1154 Location: San Diego

I have been having a problem with the image at startup, the whole image area would light up when it should be black. This would go away after about 30 seconds or so. Mark told me to check the caps on the video out board. I only found one really bad cap, it should have a ESR of about .44 and it was up to 12, no leaking or bulging ones.

Now most of the caps seem to be alright, what seems weird is all the 47Uf 16VDC seem to be all over the place, with the one at 12 being way out. Here are the readings I get on these caps. .16, .18, .2, .28, .3, 1.3, 1.4, 1.6, 1.9. Now a new cap reads .44, some of these caps are reading under and over that. I will replace the one that reads 12, but should I replace any of the others? From what I understand they have to be really bad to cause problems.

What do you guys think.

Deron.

**kal** · Posted: Thu Sep 13, 2007 12:41 am Post subject:

What projector?

**Curt Palme** · Posted: Thu Sep 13, 2007 12:45 am Post subject:

I'm not sure what your numbers mean. My Sencore lets me input the cap and voltage value, and gives me an internal resistance measurement and also a 'good/bad' readout depending on what is the max allowable internal resistance.

That max value will vary on the capacitor value.

deronmoped · Joined: 03 Nov 2006 Posts: 1154 Location: San Diego

It's a 10PG.

The ESR values are in Ohms.

I did pull the worse cap out and it showed that it was open when I tested it out of the circuit.

From what I understand, the cap has to be pretty bad to cause a problem, in other words the cap causing the fault should be pretty obvious, not just questionable. Repairing other boards, the caps that I saw that were bad, were bulging or leaking.

What have you guys found in your cap fixing experience?

Deron.

deronmoped · Joined: 03 Nov 2006 Posts: 1154 Location: San Diego

I decided to only replace the really bad cap and two others. I was in the process of replacing all of the ones that did not read perfect on my ESR meter and then I stopped myself. The reason I stopped is my soldering skills are not perfect and sometimes I make a mess of things. I was looking at my solder joints on the ones I did and the solder that did make it's way to the top side of the board was not flowing out correctly. So I re-soldered it at the top side.

Well, anyways replacing the one open cap seemed to do the trick. I fired up the PJ and it started normally, no unusually bright areas. One bonus was, the PJ had very minor streaking and that was gone! The image looks perfect, so there is no reason to go back in.

Deron.

Tinman · Posted: Thu Sep 13, 2007 4:39 pm Post subject:

Hi Deron, the only other caps to watch out for are the 10uF at 160V or so. Where was the bad 47? On the bottom of the board near a regulator???

Marc

deronmoped · Joined: 03 Nov 2006 Posts: 1154 Location: San Diego

It was C3219 (the number on the board itself, the schematic shows it as C3231) close to the center VPH06 for the green CRT. The cap read 12 Ohms in the circuit with my ESR meter, out of the circuit it read open. I guess my ESR meter was reading resistance of the circuit.

Most of the other caps were real close to what they should read in ESR with some as much as four times what the ESR should be. I did not replace any questionable caps as I have learned that I can make a mess of things and I hear the cap has to be really bad to cause problems.

I have a new video out board, but I would hate to go through the set up, not unless they come preset from the factory.

Deron.