CurtPalme.com Home Theater Forum

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A couple of weeks ago the Vertical Keystone convergence went way out of whack on all inputs. The green of course remained stable but blue and red have gone off in opposite directions in the top left hand and bottom right hand corners and can't be adjusted. The Horizontal Keystone and all other convergence adjusts still worked fine.

Then last night while viewing this very misaligned picture a 1/3 of my image from the right hand side just blanked out (completely black) from top to bottom with bowing at the centre of screen.

The shift and blanking adjusts didn't help this major collapse. I also checked the Phase setting and it remained central and correct. So now I have double trouble.
Update: And right now I thought I would check if anything else has changed before sending this and I have lost all images/inputs. No test patterns available just the Green display screen. So it looks like a trifecta of trouble hopefully on all one board. Any help would be greatly appreciated.

[dbaisey]

If you lost the signal you should still have test patterns. Hit the input list button and see if they are still listed.

What did you do last and what has changed in the room? Power failure? Doug

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Thanks Doug

All inputs settings remain in my input list but show "unregistered signal" when i manually switch to one of them. Usually you can see some sort of syncing going on when this happens but it just stays black and comes up "unregistered signal". There is no flicker of colour when you sometimes have a cable problem causing a sync error from the source.
You were right about the test pattern still being there. After checking for test patterns again in a fully darkened the room I now can see a very very faint pattern so it appears I have lost nearly all brightness.

The power supply to the proj was removed (plug out at proj) and replaced a couple of times by me in a first up desperate attempt to solve the issue but this happens involonterily quite a lot when we lose power to the grid due to storms at this time of the Monsoon season and it has never caused a problem before. All other devices on this power supply are all operating normally suggesting that there has been no major surges coming from things such as lightning strikes close by.

The power supply doesn't appear to be the concern here. I have for once not been rooting around with power or source cabling for a good while now and can see no reason that this could suddenly be the cause of my woes. There are no error codes showing up either and all fans are running normally. Could all of this drama stem from a disintergrating Deflection Board?. Please note that the humidity here at this time of year sits at about 75% and can stress out electrics beyond their limits especially in 12 yr old proj's.

[dbaisey]

Assuming the source signal is working ok and confirmed.

If you hit the kelvin button does the brightness come back to normal?

With a known good signal running select the input list and see if it has selected the top of the list, if so see if the input says video or RGB. If video select the RGB input and see if it will display.

If not you will need to try another signal entry at the top of the entry list. Move one if needed. Use temporary instead of default when asked.

Other stuff to check. Hook up a DC voltmeter to connector IB of the power supply connector, take the pin 11 voltage and see if it is at 6.3V when powered on.

While moving H position will it bring back the image? Doug

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Doug

I now can confirm that a good RGB signal is coming thru its just so faint I couldn't see it until I looked directly into the lenses
I did try the Kelvin button thing and the H position shift as I know that this can effect brightness (or was it the right hand blanking adjustment) anyway adjusting both made no difference.

I then did a check on the power supply as you suggested and pin No 11 reads about 1V not 6.3V so this looks like the first thing I should fix. I have taken the power supply out completely now and I guess its off to the local TV guy to see if he can find the fault as I don't think I have the skills to track it down unless you or somebody knows exactly what component(s) of the PWB it is likely to be. Everything looks OK. No obvious signs of failure.
Is this a fairly common fault?.

Thanks Steve

[dbaisey]

Steve,
Confirming the signal would be on a different display device. Are the test patterns also dim?
Have you tried a new signal entry after looking at the input list and items recommended above.
The way a signal is entered can emulate other problems from the system or other control boards.

Might be minor but have you tried to raise the contrast and brightness to see if it has an effect?
Might also try to put the test-normal switch to the test side. Tiny switch at the end of the video out board to see if it makes a difference.

The power supply can ramp itself down from a problem with a different board so you can still have problems elsewhere. IE: with the C drive disconnected it will ramp to about 3V at pin 11 depending if you lift CP or the CA connector. The 6.3V is heater voltage to the tubes under load so this needs to be connected to take readings from the rear of the connector, try using pin 15 for ground.

There is a 12-14 page trouble shooting flow chart in the service manual for exp techs or user repairs you would need a spare chassis to find. The power supply needs to be loaded to check it so it would be best to take the projector and the service manual so he can follow along with the voltages and board recommendations. If you had another chassis it would be easy to check.

If the heater voltage is that low you should be able to see the glow brightness differences at the end of the tube. At 6.3 it should be plenty visible. I have seen bad connections at the boards or motherboard do this also. Might be the power supply but.....Doug

[Curt Palme]

I can't see the tubes giving ANY image if the filament is really at 1 volt. Usually under 4 volts or so, there's zero emision from the tubes.

Steve, can you get a hold of MarkAW, a forum member here? He knows NECs quite well.

[Curt Palme]

I can't see the tubes giving ANY image if the filament is really at 1 volt. Usually under 4 volts or so, there's zero emision from the tubes.

Steve, can you get a hold of MarkAW, a forum member here? He knows NECs quite well.

[dbaisey]

Yes I don't think its actually that low. I think Mark has sold his Extra chassis but I'm sure someone down there may be able to help test out.

About the lowest I have seen it is 3.4V and still have a image. Might just be something simple.
If no AKB info or if it is hitting on AKB that was stored from a low setting it could do this also. The test-normal switch should show this. Doug

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Doug

Confirming the signal would be on a different display device.
Yes, the sources are normal when viewed on my LCD screen.

Are the test patterns also dim?
If you mean the proj, as stated earlier, very very faint. In fact looking again it was just the vertical lines of the test pattern grid that were faintly visible.


Have you tried a new signal entry after looking at the input list and items recommended above.
The way a signal is entered can emulate other problems from the system or other control boards.
If you mean, have I created a complete new signal entry, NO. I have selected other inputs from my list and all are consistently dim.

Might be minor but have you tried to raise the contrast and brightness to see if it has an effect?
Yes.

Might also try to put the test-normal switch to the test side. Tiny switch at the end of the video out board to see if it makes a difference.
I will give it a try when I get the power supply back in.

The power supply can ramp itself down from a problem with a different board so you can still have problems elsewhere. IE: with the C drive disconnected it will ramp to about 3V at pin 11 depending if you lift CP or the CA connector. The 6.3V is heater voltage to the tubes under load so this needs to be connected to take readings from the rear of the connector, try using pin 15 for ground.
I was wondering about this. When I tested pin No11 for 6.3V I just pulled the IB connector and probed pin 11and 12 (GND) while on.
OK, so I need to leave it connected and get the the probes in the rear of the connector while on. Will do. Didn't know about this ramp down feature of the power supply.

There is a 12-14 page trouble shooting flow chart in the service manual for exp techs or user repairs you would need a spare chassis to find. The power supply needs to be loaded to check it so it would be best to take the projector and the service manual so he can follow along with the voltages and board recommendations. If you had another chassis it would be easy to check.

That's gonna be my last resort then. 56 KG PHEW!!!!!!!!!.

I have the service manual for the PG-6000/9000 series with the "Trouble Diagnosis" section. I have an old PG-3000 in the shed. Could this be used as a test chassis?. There are a few extra voltage outputs on the 6000 series.

If the heater voltage is that low you should be able to see the glow brightness differences at the end of the tube. At 6.3 it should be plenty visible. I have seen bad connections at the boards or motherboard do this also. Might be the power supply but.....Doug[/i]

Thanks Steve

[dbaisey]

No you cant use the GP3000 for a test chassis. You can use the PG 6-9000 flow chart for trying to find the problem. GP-PG are two different models. Doug

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