CurtPalme.com Home Theater Forum

[pepsitheater]

I have a working 1208 but when I moved I found a guy locally selling his 1208s2. My tubes were pretty bad so I went ahead and bought it. Figured if nothing else his tubes would be a good replacement for mine. The unit worked though and I liked the additional features so I hung it up. Still tested and worked ok so I have been building out the room. Almost done with the room, a year later, so I went back to mess with the picture. It wasnt converging, and the convercence controls were not doing anything. Pulled the convergance board out slightly and picture was unchanged. Pushed it back in and I think the picture flickerd some, an odd sound was made, and a second later the unit went black. Now I have a scan fail light on. From what I read that would be a bad horizontal board or a bad verticle board. I had an extra horizontal board, from the guy I got the unit from, but never tested it. So not 100% sure if its good. I swppped it in and still have the scan fail though, and no picture. With the verticel board removed the green led on the horizontal board is lit. When I insert the verticle board the greed led on the horizontal board goes off and the red led on it blinks on for a second then goes off and stays off. The only verticle board I have to swap would be from my 1208 but the part numbers dont exactly match. the 1208 is R7621125 and my 1208s2 is R7621127. If I swap these am I risking more damage? I paid too much for the 1208s2 considering these are pretty worthless to most people, just cuz I still like them. Trying to decide when to cut my losses, but if I can at least test with my 1208 boards, that have all but the last number in the part the same, then that will help to hopefully get an image back on the screen. Then I can move on to seeing if the convergance board does or doesn't work. And if all else fails, So long as I dont ruin these parts I can at least put my old unit back up... So am I at risk of ruining anything else swapping these parts for testing??

Thanks for any suggustions you have!!

[Curt Palme]

You pulled out the convergence tray while the set was on? BAD MOVE!

The boards between the two sets will swap fine, if the RGB switcher and quad decoder look different, then they don't swap out, but if you did swap the tray with teh power on, who knows what you blew up. Power supplies, or boards in the tray would come to mind to start with. Always power off and unplug while pulling or putting boards in.

[Curt Palme]

You pulled out the convergence tray while the set was on? BAD MOVE!

The boards between the two sets will swap fine, if the RGB switcher and quad decoder look different, then they don't swap out, but if you did swap the tray with teh power on, who knows what you blew up. Power supplies, or boards in the tray would come to mind to start with. Always power off and unplug while pulling or putting boards in.

[pepsitheater]

Yeah it was a bad move, I got ahead of myslef and thats when bad stuff happens to me. Thanks for the reply! I didn't want to swap other boards and possibly do more damage... Fingers crossed

[Curt Palme]

Make sure the pins on the convergence tray aren't bent. Also see if the set will fire up without the tray, it should show a pix. I'd start there, without the tray installed. If you get an image, albeit unconverged of course, then you're good to go with the second tray.

[Curt Palme]

Make sure the pins on the convergence tray aren't bent. Also see if the set will fire up without the tray, it should show a pix. I'd start there, without the tray installed. If you get an image, albeit unconverged of course, then you're good to go with the second tray.

[pepsitheater]

Ok as it was with convergence card removed, it would partially turn on. No fan. Two of the green lights on the G2 board stayed dark. The red scan fail led was on. There was a glow in the neck area of each tube and a green led on each neck board was lit. No image projected.

I started swapping boards and cross testing with my 1208. When I swaped the first three boards which included the horizontal and vertical boards. No change. The 1208 kept working and the 1208s still didn't. Then I passed over the three cards that are attached and went to the power supply. When putting the known good supply into the 1208s I got a little further. Now all the green lights on the G2 board are lit and the scan fail light is off. Now the fans turn on as well. But still no picture projected. The tubes necks glow and their green led is lit.

So part way there. What is the next best thing to check? The G2 board does not look as simple to swap so I have not messed with it, but I'm guessing that maybe next?

Thanks for your suggestions, I'm at least hopefull I am getting closer to fixing my goof up

Thanks!

[pepsitheater]

Ok just swapped the g2 card. No change. Thought that might be it when I saw the pin was a bit corroded (white chalky) but got the same result with the card from the 1208. Only good news here is that my old 1208 had one issue. The green tube took about 20 minutes to turn on. Well when I put the g2 card in from the 1208s the green gun came on right away on the old beast. Good to know if I can't get the newer beast fixed.

Only things left to swap seem to be those three small boards that are wired together or ?

[pepsitheater]

Anouther update. Keep getting closer. Swaped out the EHT board. I can now get the white warm up grid and get into adjustments. It flashes up failure I2c short. And it does not pull up my source. I had my original connection in port 3. I tried a standard video connection as well though and no luck.

What do I try swapping next? So far a bad smps and EHT board.

[Curt Palme]

To diagnose, your original SMPS most likely has a blown fuse on it, which caused the scan fail light to come on. THe EHT board may be as simple as a fuse as well, there's one in the lower left corner of the board.

THe fact that you now have menus means the projector is 99% working, but with an I2R short message, you won't be able to change a lot of functions in the set. MY guess is that the firmware of the replacement convergence board is different than the original, giving you that error message. Take a peek at the module contacts of the original convergence tray, and straighten any that are bent. If they all look OK, then I'd try putting the original tray back in. THere's a good chance nothing is wrong with it, you blew the two other boards when you put it back in with the power on. Worst that will happen is that another fuse will blow on the second SMPS, but you need to take that chance at this point.

[Curt Palme]

To diagnose, your original SMPS most likely has a blown fuse on it, which caused the scan fail light to come on. THe EHT board may be as simple as a fuse as well, there's one in the lower left corner of the board.

THe fact that you now have menus means the projector is 99% working, but with an I2R short message, you won't be able to change a lot of functions in the set. MY guess is that the firmware of the replacement convergence board is different than the original, giving you that error message. Take a peek at the module contacts of the original convergence tray, and straighten any that are bent. If they all look OK, then I'd try putting the original tray back in. THere's a good chance nothing is wrong with it, you blew the two other boards when you put it back in with the power on. Worst that will happen is that another fuse will blow on the second SMPS, but you need to take that chance at this point.

[pepsitheater]

Made no progress tonight, but lots of testing.

Can't swap the three RGB boards I don't think. I'm assuming these might be bad since I can't see and video source?
Didn't swap anything related to the controller module or deflection switching module. Seemed unnecessary
The 1208s2 vertical board worked in the 1208 (interesting to note a working 1208 vertical bord does not work in the 1208s2)
Horizontal board worked in the 1208
Focus shift board work
Tested the fuse on the bad SMPS. Fuse was ok, so something else must be bad
Tested fuse on bad EHT. Fuse was ok here as well.
Quadrupler swapped and tested ok
Power main should be ok givin its powering up.
G2 board worked in the 1208
Front IR receiver works when convergence board is in

So now I went back to the convergence tray. I can assume I need new RGB boards but why bother if I can't get the convergence tray to work

No tray in the 1208s2 I get Failure I2c short
Tray inserted I get the same result

I can't try the 1208 convergence tray, they are completely different.

I happened to have a spare convergence driver module in my parts box. This spare also has attached to it three other boards. The green convergence module and two other that I don't know what they are.

Swapped in this driver, re checked all the pins a dozen times, and none were bent. Put the tray back in and same result. I can get a menu and a grid but no source and the same Failure short on I2c bus.

I am out of things to swap. I don't have a spare converg output module or astigmatism module.

Now going back to the reason I even stupidly took out the convergence board...projector on displaying my sourse image in generally correct size but unconverged. No I2c short on bus, just simply not alligning. And in the menus you could try to make convergence adjustments but nothing actually moved. So I removed tray to confirm it had no effect on the image but failed to turn the machine off before putting it back in.

What am I missing and not thinking about? Would it be the output module and the three RGB cards that I don't have replacements to test with? Is there a way for me to test them for shorts?

That's all the parts I can think of lol...

Thanks again!!!!!!

[km987654]

Port 3 is not a VGA connections so unless you have the correct Port 3 cable you are wasting your time. You should try a Port 5 connection RGBVH.

Do a google search for Barco I2C failures and you will find a PDF which describes those issues. If you have an image at all then the RGB end stages must be working so they won't be your problem.

[Curt Palme]

Well the I2R error won't narrow down where the faulty board is sadly. All that says it that communications on the serial data buss isn't working. A bunch of boards have special Barco digital potentiometer chips on them. These include the H board, V board, convergence board, H shift/focus board, controller board and video boards. you'll see them by the Barco stamp right on the chip. One of those is shorted, probably caused by a voltage spike from either pulling out or shoving the controller board back in.

If you don't have spares, then you can either send me the boards you can't swap for testing, or just buy spares. I'm selling them dirt cheap for the most part anyway, it's probably cheaper to buy spare boards than send yours in for repair.

[Curt Palme]

Well the I2R error won't narrow down where the faulty board is sadly. All that says it that communications on the serial data buss isn't working. A bunch of boards have special Barco digital potentiometer chips on them. These include the H board, V board, convergence board, H shift/focus board, controller board and video boards. you'll see them by the Barco stamp right on the chip. One of those is shorted, probably caused by a voltage spike from either pulling out or shoving the controller board back in.

If you don't have spares, then you can either send me the boards you can't swap for testing, or just buy spares. I'm selling them dirt cheap for the most part anyway, it's probably cheaper to buy spare boards than send yours in for repair.

[pepsitheater]

Ok well I get the error even with the convergence tray out. So its not sending the fault (yet at least). I will install the horizontal, vertical and h shift board one more time into the old 1208 and be sure its not them. Even though I get a source picture on it, I may not have looked for the error. Then I will know whitout a doubt those work, and I am down to the three video boards or the controller board.

Can I swap the 1208 and the 1208s2 controller boards? I had not thought to swap those...

Are any of the three video boards swapable from the 1208 to the 1208s2? The connection of the middle board to the controller board was in a different spot so I made an assumption it, and the otheres that connect to it, wouldn't swap correctly.

What would the three video boards cost? I guess that is my next step if I want to resurect this beast.

Thanks so much for answering these questions!

[Curt Palme]

Can you email me at curtpalme at shaw.ca

Try swapping the controller boards, but they may not work due to different firmware, but try it, you won't hurt anything.

[Curt Palme]

Can you email me at curtpalme at shaw.ca

Try swapping the controller boards, but they may not work due to different firmware, but try it, you won't hurt anything.

[pepsitheater]

Another update!
I remembered I hadnt re tried swapping the shift focus board after replacing the SMPS and the EHT. There the I2c failure hid. With the 1208 shift board in, the 1208s2 now gives me my source video. Hurray!

So back to my problem that started this mess. No convergence. I tested all the pieces of the set up and here are the functions that still don't work (meaning nothing changes when it should)
Vertical centerline bow
Vertical centerline skew
Seagull correction
Left keystone
Left bow
H centerline bow
H centerline skew
Tob bow
Top keystone
Bottom bow
Bottom keystone
Seagull
H size
All convergence other than raster shift
Dynamic astigmatation

Same results with two different horizontal boards and two different vertical boards and two different convergence drivers.
Same result with no convergence board in (other than now I get an error on the screen when trying to perform the function.




No other errors show...suggestions at this point? Convergence output board might be all that is left. Anyway to test or repair it?

[km987654]

[Curt Palme]

True KM, but 'I2R short' means that there's no communication going on via the serial data buss due to a short on one or the other line.

[Curt Palme]

True KM, but 'I2R short' means that there's no communication going on via the serial data buss due to a short on one or the other line.

[km987654]

[pepsitheater]

[Curt Palme]

OK, duh, sorry! Yes, either the convergence output board or convergence driver board has issues.

[Curt Palme]

OK, duh, sorry! Yes, either the convergence output board or convergence driver board has issues.

[km987654]