CurtPalme.com Home Theater Forum

**Curt Palme** · Posted: Tue Mar 17, 2015 4:42 pm Post subject:

No, the later 1209s video boards are not compatible with the older ones. I did get your email, give me a few days to test the video boards, as that is what it sounds like you need.

winny · Posted: Tue Mar 17, 2015 5:28 pm Post subject:

No problem.

I found the following in my stash:

Complete data 808s Smile

R7621745+R772174S
7617481
R7621055

Anything compatible?

**Curt Palme** · Posted: Tue Mar 17, 2015 6:13 pm Post subject:

take a look at the board numbers on the 1209. If they are the same, then yes, you can swap them. I am not near my 1209 manuals right now.

km987654 · Posted: Wed Mar 18, 2015 2:12 am Post subject:

R7621055 Thats a port 3 board. If it doesn't work in your projector it would be the only one from the 800 to the 909 that it does not as its the same board in all those projectors.

winny · Posted: Thu Mar 19, 2015 9:38 am Post subject:

From my old notes, my 1209 did have R7621055 in it. My spare has lots of mods on it and a VGA-port on the back side. Got in along with other parts from some old deal.

How imune are these projectors to faults? Spot burn should be handled by scan failure detection on other boards but what about a short circuit on some board with unknown status? I don't have a test projector/set. Same problem as a roling repair on a car, you can't take too much chances or you won't have any means to get to work on monday morning.

km987654 · Posted: Fri Mar 20, 2015 5:32 am Post subject:

winny · Posted: Fri Mar 20, 2015 11:42 am Post subject:

Took it to work and tested in on my bench. Pulled 25 mA on each rail. -12V was -0.3 V and the regulator was quite hot! Good thing I tested it first Smile

EDIT:
Good thing I check which connection is ground first. Rolling Eyes

55 mA on the +17V rail and 25 mA on the -17V.

R65 is the only thing heating up slightly so should be good to test.

winny · Posted: Wed Apr 08, 2015 11:46 am Post subject:

Ok, it's officially dead now. A solid 30 minuts of heating up but it kept refusing to sync to any input.

Took R76211127 out. Nothing visible but C75 and C76 (the big ones in the middle, close to the heatsink) sits very close to heat sources. Does a high scan frequency load the +9V and -17V more? In that case, it could explain why I could see the internal patterns but not sync to external sources.

I'll unsolder them and see if I can find that LCR-tester somewhere.

Has anyone experimented with these? Increase the value/decrease ESR, does it come with any side effects?

winny · Posted: Wed Apr 08, 2015 12:32 pm Post subject:

-17V rail, 1000 uF:
917 uF, 105 mohm @ 120 Hz

+9V rail, 4700 uF:
4248 uF, 46.9 mohm @ 120 Hz

Should be fine.

Any other candidates?

winny · Posted: Wed Apr 08, 2015 6:16 pm Post subject:

Put the vertical board back. No explosion.
Swapped R7617481 to my old half-broken 7617481 with no red and the symptom was identical but no red.

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 6319 Location: Australia

That 4700uF is more than 10% out.

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 6319 Location: Australia

That 4700uF is more than 10% out.

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 6319 Location: Australia

How many other boards to swap out?

winny · Posted: Thu Apr 09, 2015 7:29 am Post subject:

E-caps are usually +-20 % and the manufacturers aim for -10 % and 10 % distribution around that.

Nothing compatible it seems. Sad

The downside of owning an non-s and an s-projector, not to mention that the /2 is the most unusual bird in the mix so more uncommon boards.

winny · Posted: Tue Apr 14, 2015 8:23 am Post subject:

I'm still planning to swap boards until I manage to narrow this down.

The /2 seems to be an unusual bird in the flock so I'm still curious what might be compatible or not. Found the following inside my 1209/2:

R7621127
R7621127s
R762700
R7621175s
R7621055
7617481 (this is compatible with R7617481, or Barco just forgot the leading R?)
R762271
R7621085

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 6319 Location: Australia

Id say only the numbers matter, the R seems to be on every Barco part number ive seen for a CRT.

**Curt Palme** · Posted: Tue Apr 14, 2015 2:41 pm Post subject:

This hit me last night, I think I know what the problem is with this case.. but, I've only seen this problem in the 1209s chassis a couple of times, not the 1209.

This may be low tube emission. I've seen this in high hour chassis in a couple of planetarium projectors, chasing the issue all over the chassis, until in desperation we swapped tubes.

It seems that a low emission tube can upset the G2/AKB circuit, to cause flashing. The planetarium projectors did it mainly when in the G2 setup mode, to turn off the green LEDs, and of course the 1209 chassis did not have that menu setting. Still, the strobing in the 1209s was a video or G2 flashing, and had nothing to do with HV.

I've told winny to disconnect the HV lead and CRT socket off the back of each tube one at a time, to see if the other two tubes then light normally.

Not sure why I didn't think of this before, but I have a feeling that's what it is. Changing the G2 levels on the G2 card may also fix this..

winny · Posted: Tue Apr 14, 2015 8:21 pm Post subject:

All three, one by one, no change.

CasetheCorvetteman · Joined: 09 Nov 2008 Posts: 6319 Location: Australia

winny · Posted: Wed Apr 15, 2015 11:43 am Post subject:

Not going to happen but that Curt $600 1209s is tempting.