CurtPalme.com Home Theater Forum

[TS1493cc]

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Hi to everyone on the CRT forum,

First a little background info, I got my first CRT back in 2008, a slightly battered NEC PG9 plain. Curt's site was a brilliant source of information and after reading the various guides and calibration tips I was able to setup the PG9 and it cast a wonderful picture. I used the PG9 ceiling mounted with a DIY screen for films and video via PC up until 2013ish where the PG started to show signs of distress. Finally the Blue tube lost it's picture and the projector had trouble locking onto input sources.
I replaced afew bad capacitors on the system board and the signal locking issues were resolved. I followed the fault finding procedures in the NEC service manual and came to the conclusion that the Blue VPH06 video amplifier had failed on the Video out board. The blue tube could produce the AKB lines, the menus and depending on its mood a bright raster (sometimes) but no video. The blue tube does not appear to respond to the Kelvin commands. I also found that the PG9 was totally full of leaking capacitors! visibly leaking electrolyte. I was trying to hold on for a new Video out board or another PG9 to crop up on Ebay to swap boards out but nothing came up. The plan was to get the blue tube outputting video again then bite the bullet and re-cap the whole set.
In the end a very good condition Barco Cine 7 came up for sale with some extras and a nice screen so I went for that. My thinking behind this was it was a much newer machine built Jan 2002 and it is quite low hours (514hrs Atm) and the tubes are pristine with no visible wear to the phosphor. The previous owner was the original owner having bought the projector new for his home theater.
I was very pleased with the Cine 7 as the picture it throws is quite comparable to what MY cranky old PG9 could achieve in my hands.
I was running the Cine 7 table mounted to test it out fully before going to the effort of getting it on the ceiling. The first 100 or so hours I put on it have been great and I was just starting to think that I had a winner when a problem became apparent.

Switching on the set powers up fine and operates normally. after about 5 mins of running there will be a quiet snap! of a HV arc and the picture on screen will shrink by 5% momentarily both horizontally and vertically before reverting back to normal. It will then continue to repeat this every 30-40seconds. I have looked into the set in the dark to see If any arching is visible but this has revealed nothing.
Listening for the snaps they appear to be coming from the HV splitter area. Pulling out the HT leads to the tubes from the splitter and powering up does not eliminate the snaps.
After each snap there is sometimes an unhappy whine from the quadrupleler area that lasts between 2-20 seconds.

From this I feel that I might need to replace the HV Splitter? (Barco p/n R762907) Is there anything else I can do to further troubleshoot this problem? I do not want to run the projector any longer as I fear that eventual damage will be done.

Any help on this would be greatly appreciated as the Cine 7 was otherwise working beautifully and I was quite content with the picture!
Thanks.

[Curt Palme]

Tough call, not a usual problem. Shrinking on all sides indicated too much HV, or the LVPS part of the SMPS being bad, but the Barcos are so well protected that neither typically occur unless the HV or LVPS shuts down completely, but that would give no picture.

About all you can do is swap parts and boards out, but finding spare Cine 7 parts is hard, as the older 708 modules are mostly not compatible with the newer Cine 7. If you want, send me the SMPS as that's where the HV and LV circuits are on, and I can test them in a set here. Or, get a HV probe, and monitor the HV out of the splitter.. carefully!

[Curt Palme]

Tough call, not a usual problem. Shrinking on all sides indicated too much HV, or the LVPS part of the SMPS being bad, but the Barcos are so well protected that neither typically occur unless the HV or LVPS shuts down completely, but that would give no picture.

About all you can do is swap parts and boards out, but finding spare Cine 7 parts is hard, as the older 708 modules are mostly not compatible with the newer Cine 7. If you want, send me the SMPS as that's where the HV and LV circuits are on, and I can test them in a set here. Or, get a HV probe, and monitor the HV out of the splitter.. carefully!

[CasetheCorvetteman]

Unscrew the splitter from the metal frame and run it in air away from metal.

[cosaw]

Up until what Curt said I was gonna suggest looking for a 701 or 708 - they're one of the more available crt pjs in the UK. Even Cine 7 machines pop up every so often on ebay. Can't remember when I last saw an NEC.

Where abouts are you in the UK?

[TS1493cc]

Thanks Guys for your replys!

Thinking about it The picture shrinking is really more of a slight glitch that lasts for a split second, I think I overstated the shrinkage, perhaps it is only 1-2% at the most
Casethecorvetteman I shall try moving the splitter away from the chassis to see if that helps, Unfortunately I am now away from home until the weekend so I'll have to wait until then to try that out.
Cosaw, I am from Hertfordshire, I guess keeping an eye out for another Cine 7 would make sense as a long term parts backup, I've read that the Barco splitter is pretty much the same between most models? is this true? if so finding another to test out in the set could be a good option to either cure the problem or eliminate a red herring.
Curt, Thankyou for your help I Hope it's not the SMPS. I shall see if I can eliminate other possibility's first, I'd hate to risk shipping the power supply to the states and back if its avoidable. However your services would be very welcome if it does come to it!
I had a conversation with a guy at work today, he's got a hand in running an amateur dramatics society that uses an old theatre that at one point was converted into a cinema. Apparently the 35mm film projectors from the 1930's are still there. He said that the screen (still there at the back of the stage) was the largest in the area so I think I'll have to have a look just for interests sake.

[CasetheCorvetteman]

Keep is posted mate Its not out of the question for a Barco splitter to go bad.

[TS1493cc]

Ok so tonight I have isolated the splitter away from the chassis (with a pint glass ). I also cleaned all the soot off the splitter and HV cables and I ran the projector for an hour and there was no glitching on the screen nor any noises from the quadrupler - Result! However I then put the splitter back in position and ran again and now there is HV streaming out across the top of the splitter from the base one of the output posts! there are also thin arcs visible occasionally from the top of the post going to the other HV cables.
So I gather from this I need to replace the splitter and probably the HV cables too? Are new HV cables available? Does Curt stock these items? I feel like I'm not far from a fix with this now if the parts are available!

[cosaw]

I'd guess it is more likely the splitter than the actual cables but I can't confirm that. Don't know if you could tape up the "output post" with plenty of insulation tape. Only to see if it makes a difference.

You'll just have to wait on me a bit till I see where I'm up to with regards to working splitters. If we agree that I've got something suitable then I can maybe lend you something to fault find. No promises, quads and splitters are like gold in the UK.

Changing the splitter you'll need to do a tiny bit of soldering.

[Curt Palme]

Yes, the splitter is bad. It's one of the later ones, that do that more commonly than the older ones.

[Curt Palme]

Yes, the splitter is bad. It's one of the later ones, that do that more commonly than the older ones.

[CasetheCorvetteman]

Well how bout that eh? 2 from 2 in a week

[cosaw]

[CasetheCorvetteman]

It takes a bit of lateral thinking and some prior reading, mixed with a bit of experience, and youre laughin your bloody head off

[TS1493cc]

Again thanks for the help on this, I'm quite happy doing soldering work. I'm now very much in the market for good Splitter. I found once on the forums some Info about which Barco HV part combinations were compatible but now I can't find the thread. Does anyone know which splitter part numbers can/can't be used with my projector?
Thanks

[TS1493cc]

Ok so I've had another look at the Cine7 and it turns out the Quad is also defective, it has a small burnt area near the metal mounting bracket and an occasional arc occurs there while the set is running.
Theres a chance of getting a 701 as a spares machine. I would swap out the whole powersupply, Quad and splitter from the 701 into the Cine7 to fix the HV Problems.
Does anyone know if the LVPS+Quad+splitter is compatible between the 701 and the Cine7? I'm hoping they are a direct swap when kept together as a matched set.
Thanks.

[Curt Palme]

The LVPS is not, the quad and splitter should be.

[Curt Palme]

The LVPS is not, the quad and splitter should be.

[TS1493cc]

ahh, well thats good news. I only thought of changing the LVPS with the quad and splitter to maintain compatiblilty between the LVPS and the quad But if the quad+splitter goes straight in the Cine7 then thats great. I guess not much in the rest of the 701 set is compatible? Seems a waste but I'm probably going to scrap the whole 701 after robbing the Quad+splitter. I don't think there would be any demand for 701 spares?
Thanks Curt for you help.

[Curt Palme]

Nope. I've gotten rid of most of my 701 stuff.

[Curt Palme]

Nope. I've gotten rid of most of my 701 stuff.

[TS1493cc]

Ok So I've acquired a working 701 Data set, the tubes have text burn so I have no problems breaking it for parts. The 701 is fully functional though, I've run it for quite a while and it was quite happy.
Now I've tried swapping the 701 Quad and splitter into the Cine7 and the arching has gone but bright scenes make the Cine7 whine from around the Quad area and the Picture sort of glitches when this happens. Ramping the brightness control up and down makes the whine come and go with the brightness level. Does this mean that the power supply is also bad?
On a side note I've put the Cine7 quad and splitter into the 701 and apart from the occasional arching from the burnt area of the Quad it is still running happily
Any help is very appreciated!

[Curt Palme]

try exchanging the splitter.

[Curt Palme]

try exchanging the splitter.

[TS1493cc]

Sorry I swapped both the Quad and the splitter from the 701 into the Cine7, are you saying try it with the 701 Quad and the Cine7 Splitter?