CurtPalme.com Home Theater Forum

JohnAd · Joined: 12 Mar 2012 Posts: 21

Hi to everyone still battling on with CRTs.

A couple of weeks ago I was sitting in the same room as my projector while powered off and heard an ominous electrical crack sound. Sure enough when I tried to power it up I got nothing and looking at the troubleshooting pages it seemed like a farly textbook SMPS issue so I ordered a replacement from Curt.

I've stuck the new one in and now get a new issue. The projector now comes out of standby and the fans start but then after a about 10 seconds it powers off again. I've tried removing each of the boards and the same thiong happens each time.

As far as the lights go the board with the row of LEDs has the far left one dark (the one next to the red one) and the 4th from the right out, all the others are on.

On the controller unit the error light is lit, when I come out of standby the RCU light comes on and the error light goes out but then after 3 seconds the RCU light goes off andthe error light come son again and then in a few seconds the fans go off.

Does anyone have any clues as to what is wrong or more tests that I can do to isolate the next component that need replacing.

Many thanks

John

**Curt Palme** · Posted: Thu Jun 15, 2017 9:13 pm Post subject:

On a Barco, red is bad, green is good. It's pretty common for this to happen, and to correct it, you need to adjust the H width control on the power supply.

I don't have a pix on the site, but the trimpot is about an inch down on the board close to the outside edge of the daughter board, closest to the lenses. There's about 3 pots on that board, the H width one is the one not covered with red sealant paint.

Start with the control where it is now, and turn it clockwise about 1/8 turn. Turn the set on and off each time. At some point the red light will come on, but then go off, and you'll get a pix. Too wide or too narrow, and the red scan fail light will come on.

It's also possible but unlikely that either the H or V board died, and that's what took out the power supply, but that's really rare. I tested the supply in a 1209 here, and it was fine, but that width setting changes from set to set.

JohnAd · Joined: 12 Mar 2012 Posts: 21

Curt

Thanks a lot for getting back and I'm glad there is some hope.

If I've understood correctly it's the pot marked P2 that I should adjust. I'll give that a go tomorrow evening and report back.

John

JohnAd · Joined: 12 Mar 2012 Posts: 21

Oh dear, trying out all the different positions didn't seem to help, still the same behaviour with the lights.

Is there anything else I can do to help diagnose the issue?

John

**Curt Palme** · Posted: Fri Jun 16, 2017 7:16 pm Post subject:

the red LED is on continuously, correct? That will prevent the one green one from coming on.
The set is in scan fail mode. Most likely the H board is bad, which took out the SMPS. Unfortunately, short of swapping the H board, there's no tests you can do. I'll respond to your email, I'd send down the V board as well, as it can cause the same symptom.

JohnAd · Joined: 12 Mar 2012 Posts: 21

Curt

Thanks, as always, for the very rapid and helpful response.

Yes the red led is always on so it does sound like a H or V board issue and getting both shipped together sounds like a good plan just in case

John

**Curt Palme** · Posted: Fri Jun 16, 2017 8:23 pm Post subject:

OK, let me test them. Since it will be a couple of weeks, you can also swap over your sub board from your original SMPS to mine, and see if that gets it going. Once in a blue moon the replacement SMPS can be finicky working in other 1209/1209s models.

JohnAd · Joined: 12 Mar 2012 Posts: 21

Have just swapped out the sub board and while that hasn't got things working again there did seem to be a slight change in the lights. The red one still is always red but the 2 ones that weren't lit before did come on green briefly.

John

**Curt Palme** · Posted: Fri Jun 16, 2017 10:12 pm Post subject:

All pretty normal. Try adjusting that P2 trimpot again, as the setting will vary from supply to supply.

JohnAd · Joined: 12 Mar 2012 Posts: 21

Same behaviour at all the angles of the trim pot.

JohnAd · Joined: 12 Mar 2012 Posts: 21

OK after replacing h and v boards still getting the same issue, one continuous red light with 2 green ones coming on briefly.

In you mail you mentiomed there were some more thing to try aside from the trimpot.

Thanks

**Curt Palme** · Posted: Sat Jul 15, 2017 1:53 pm Post subject:

Check the V scan yoke switch on the yoke board, on the inside of the tube lid. Check all yoke connectors, and all solder joints on that board (power off of course). Once in a blue moon those switches go intermittent, or there's a bad solder joint on that board.

JohnAd · Joined: 12 Mar 2012 Posts: 21

Not exactly sure what I'm looking for but the the switch labeled v scan reversal switches on http://www.curtpalme.com/Barco1208_Layout5.shtm seems to be broken, the spring wasn't properly attached and it does not seem to switch properly without the spring I can move it from one end to the other but there isn't any click.

**Curt Palme** · Posted: Sat Jul 15, 2017 5:49 pm Post subject:

Yes, but don't do it with the set on. If that switch moved inbetween settings, then you'll get a scan fail. The switch typically is either at the one extreme or other. If you get the image back, then put tape around the shaft so that it stays in place.

JohnAd · Joined: 12 Mar 2012 Posts: 21

I get nothing with the switch at either extreme, the red light seems to stay on.

**Curt Palme** · Posted: Sun Jul 16, 2017 2:35 pm Post subject:

Unfortunately at this point it's going to be very difficult to troubleshoot this without a scope, meter, module extender cards, etc. There is a tiny chance that the video switcher boards (quad decoder and RGB input board) could be bad, but I doubt it, as I've only had one set cause a scan fail out of the 100s I've serviced with one of those boards being bad. The three boards I've sent cause almost all of the scan fail problems, and now it's a matter of measuring waveforms, etc to see where you're losing the deflection. About all you can do at this point is measure the continuity of the V deflection switch, to make sure all 4 sets of contacts are actually making contact within the switch.

JohnAd · Joined: 12 Mar 2012 Posts: 21

OK thanks, I've checked the the vdefelction switch continuity and as far as I can tell it seem to be working. Looks like I'm at the end of the line for my CRT journey Sad

**Curt Palme** · Posted: Sun Jul 16, 2017 4:02 pm Post subject:

Yeah, sad for sure. Sorry I couldn't be of more help. Did you try adjusting the H width pot again? I think I mentioned, all three of the boards I sent you were out of my working test chassis, so maybe play with it a bit again and see if you can't get it to work..

JohnAd · Joined: 12 Mar 2012 Posts: 21

Yes I did,at each 1/8 turn, is the right procedure, unplug - turn pot - reinsert power - out of standby - hope? Since I had to swap out your smps daughter board for my one is there anything else that could be out?