CurtPalme.com Home Theater Forum

TonyM · Joined: 11 Dec 2011 Posts: 19

Hello! I have Barco Graphics 801s projector that is just sitting in our basement. We had it up and running until 2005 when our home theater was brutally transformed into a storage room

Anyways, I recently decided I want to revive this fantastic piece of equipment and get some movies rolling again. My problem is that there seems to be a problem with the blue tube as it is completely dark when I turn on the projector. the red and green tubes are functioning, but the blue tube seems completely dead. When I look into the tube there is no sign of any light.

I remember just before we closed down our home theater back in 2005 that there was a problem with the blue tube. Back then it would flicker on and off occasionally, but it would always come back on.

I found this thread:Blue tube dying on Barco 808G
but its for another model, so I thought I'd start a new thread to see if I can get some help.

I am a newbie when it comes to understanding the electronics inside the projector. I do however understand that this is high voltage and can be DANGEROUS. So Where should I start in troubleshooting this?

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

First I would say always make sure it's unplugged before you put your hands in there. As far as your problem, providing the blue is not turned off via the remote, you may have a bad neck board. You could try swapping with another color.

km987654

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

TonyM · Joined: 11 Dec 2011 Posts: 19

I have it connected to my computer using port 3. Still no blue. I think the cable should be fine.

How can I verify that blue is not turned off via the remote? I was going through the menus but couldn't find it.

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

It may not have a way to shut off individual colors other then in the test patterns. I dont know the Barco remote that well. How about the internal test patterns? Is there blue in there?

TonyM · Joined: 11 Dec 2011 Posts: 19

I've been going through the test patterns, green/red works, but green/blue still leaves the blue shut off. I also tried the "color select" option under random access adjustment mode and when I select blue the image goes totally black.

I'm gonna turn it off now for the night and see if I can swap the neck boards tomorrow like you suggested macgyver. Maybe you can give me some input on how to proceed with that?

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Again, not knowing Barcos that well, isn't port 3 a 9pin din connector?

TonyM · Joined: 11 Dec 2011 Posts: 19

km987654 · Posted: Mon Dec 12, 2011 12:52 am Post subject:

Try port 5

TonyM · Joined: 11 Dec 2011 Posts: 19

TonyM · Joined: 11 Dec 2011 Posts: 19

Ok, so I tried connecting a source to the s-video port today. Same result: green and red are ok, blue is dead.

Any advise on how to proceed with troubleshooting the neck board?

**Curt Palme** · Posted: Tue Dec 13, 2011 1:43 am Post subject:

Directly over top of the CRT socket is the video amplifier board. One per tube, all three are identical. Swap the blue video amp with the red or green. See if the blue now works, and the red or green is dead. If so, the board is bad. I should have stock of a replacement.

TonyM · Joined: 11 Dec 2011 Posts: 19

Ok, I've located the neck board/video amplifier board (I think) - see picture. How do I go about swapping them without breaking anything? Do I take the board itself off of the tube, or only the cables?

barclay66 · Posted: Tue Dec 13, 2011 7:52 pm Post subject:

Hi,

Neck board and amplifier are two separate parts. The amp is the module that now is hanging loose already. Go with this first. It has one connector in front and one at its back side. Unplug both, unscrew both screws of the adjacent amp, unplug this one too, swap the amps, reconnect, mount them back and test.
If now green is out You will know the amp now connected to green is bad. If blue stays dark then it may either be the blue tube or the Focus/G2 board could be an option too. If You follow the somewhat thicker red cables (carrying the G2 voltage) from each of the neck boards You will find it. It has the group of amber and red LEDs on it. There You could try the same color swap. Pull the black isolation cap of the blue G2 cable up, grab the connector with a needle pry and by gently wiggling unplug it. Do the same with the green G2 cable. Reconnect an isolate them after swap, then test. If now green stays dark then its the Focus/G2 board. If not then most likely its the tube...

Regards,
barclay66

TonyM · Joined: 11 Dec 2011 Posts: 19

I tried switching the amplifier boards between the blue and red tubes. Red still works, and blue is still dead, so that rules out the amplifier boards.

I will try to switch the G2 cables like you suggested.

How long do I have to wait before I touch anything after unplugging from power so I don't end up electrocuted?

barclay66 · Posted: Tue Dec 13, 2011 9:22 pm Post subject:

Hi,

You just should wait some minutes and use isolated pliers. The G2 voltages are almost instantly gone after shutdown. This is different to the anode connector where You can get an electric shock even after some more time...

Regards,
barclay66

Edit: Did You check if the blue tube's neck shows the same heater glow like the other ones? Just another idea...

TonyM · Joined: 11 Dec 2011 Posts: 19

Just to be clear: Is this the G2 board that you are talking about? (see picture)

So I just swap the blue and green cables? I notice the green has two cables going into it. does this matter?

TonyM · Joined: 11 Dec 2011 Posts: 19

Oh, and I didn't check if the blue tube's neck shows the same heater glow like the other ones. Not sure I know exactly what you mean? But maybe I should do that before I change the G2 cables?

TonyM · Joined: 11 Dec 2011 Posts: 19

Just a couple of other things that I noticed: on the amp board there are LEDs with text that says: "LED must be off at correct G2 setting in G2 adjust menu". When I have the PJ powered on all three of these LEDs are lit up.

Also, we built a hush-box for it when we had it up and running the last time, and we took off the plastic cover of the PJ. Is that a bad idea for air circulation which might have damaged the blue tube somehow? I have two fans mounted in the hush-box itself for extra cooling, but still.