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Discussion Starter · #1 ·
Hi,


I am assembling a 9500 that I had as a spare over here that I plan to give away to a relative as her wedding present.


It's a 9500 (non-Ultra). I changed the belly fans with 4 12 VDC fans; and in addition to that I did not do much else. It's been a while since I don't test that PJ, but anyway, I power it on, everything looks fine, HV crackle OK, but no light on any of the 3 tubes. I have a number of CLMs over here but all are 4.2c, and I wonder if 4.2c works in non-Ultra machines.


I have already tried swapping VIMs, CLMs (3 of them). I have not swapped VNBs as I think it would be too weird for the 3 of them to fail.


I don't have any signal connected to them, so I am trying to see the built-in patterns. I press SOURCE 01, SOURCE 02, etc. to see if I hear the VIM relays and I don't, so I think it could be the CLM - but as I've said I've already swapped it a few times.


Any ideas?
 

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Discussion Starter · #3 ·
Yes, filaments on all 3 tubes are lit.


I've tried increasing brightness (pressing brite and then UP a lot). Nothing on the screen but I hear a faint noise when doing it (electronics sweating it, I guess).


I'll change the LVPS just in case. Any other ideas?


rgs - Andres
 

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Try the HVPS too, But you may have disconnected the HVPS line when doing the belly fans. You may have to tear it down again to see. those cables go right in the belly fan area. Aslo if the draw from the belly fans are not right on the LVPS for some reasn the HVPS wont go on. It might be that, if you have an extra bely fan try with the original fans, disconnect your new fans from the 24 v line and connect these. you may ba able to reach in woth out a tear down.


Athaansios
 

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Discussion Starter · #5 ·
Good point Athanasios. I hear the HV crackle so the HPVS works, but you are right about the G2 lines.


I will try tonight!
 

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I would still try the fans, i think the LVPS has a current sensor, not sure but i remeber that i had only two fans running on a new set up and the HVPS crackle would be heard but no image. I got the other fan working and the image came up, it might have been coincidence but not sure.


Athanasios
 

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Discussion Starter · #7 ·
Hi - I just did some more tests on this set.


For some reason the G filament is not lit, but the R and G are. I already swapped VNBs and two G tubes and the little umbilical cable and still no G filament lit. Any ideas?
 

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Discussion Starter · #8 ·
I just did one experiment: I connected the umbilical cord from the G tube to the umbilical socket of the B tube (leaving the B tube disconnected). I connected the Pj to mains and the G filament is lit... Every other connector: G2, RCA video, etc. are left as-is, so it should be something about the umbilical connector.


I tested conductivity of the Heater 1 & 2 lines and they are all OK (for the 3 tubes).


What makes the filament lit? Just Heater 1 & 2 or does it need any extra voltage for it to be lit?


Thanks.
 

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Quote:
Originally Posted by antorsae /forum/post/15762211


I just did one experiment: I connected the umbilical cord from the G tube to the umbilical socket of the B tube (leaving the B tube disconnected). I connected the Pj to mains and the G filament is lit... Every other connector: G2, RCA video, etc. are left as-is, so it should be something about the umbilical connector.


I tested conductivity of the Heater 1 & 2 lines and they are all OK (for the 3 tubes).


What makes the filament lit? Just Heater 1 & 2 or does it need any extra voltage for it to be lit?


Thanks.

Hello


Just Heater 1 and 2. Your 14 pin umbilical could be bad, or a problem on the neckboard foil.


.
 

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Quote:
Originally Posted by antorsae /forum/post/15762211


I just did one experiment: I connected the umbilical cord from the G tube to the umbilical socket of the B tube (leaving the B tube disconnected). I connected the Pj to mains and the G filament is lit... Every other connector: G2, RCA video, etc. are left as-is, so it should be something about the umbilical connector.


I tested conductivity of the Heater 1 & 2 lines and they are all OK (for the 3 tubes).


What makes the filament lit? Just Heater 1 & 2 or does it need any extra voltage for it to be lit?


Thanks.

try going the other way too, the umbilical from the green UMB socket to the blue VNB connector and see if it lights the filament.


Athanasios
 

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Discussion Starter · #11 ·
OK - I fixed the heater issue: The G Heater1 line was not making proper connection, some cleaning fixed it; so now all 3 heaters are lit.


But I am back with the original problem: when I power up the PJ, I get the HV crackle ut there is no image on any of the 3 tubes. I've already tested swapping CLMs (2), VIMs (2), LVPS (2), HVPS (3), and I also replaced the belly fans with the original ones just in case.


Now that I've fixed the G heater, one thing I noted is that when I power down the PJ sometimes I see a bright dot in the center of the G tube. I only see this on the G tube.


Any idea? Could it be that one tube is shot or otherwise the spotkill circuit is always active, and is then inhibiting raster, etc.?


In addition, when I press SRC 01 or SRC 02 in the remote, I do not hear the VIM relay, which I guess I should (although I have no sources connected to ether VIM input).


Ideas?
 

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Quote:
Now that I've fixed the G heater, one thing I noted is that when I power down the PJ sometimes I see a bright dot in the center of the G tube. I only see this on the G tube.

hmmm spot kill seems not to working on the VNB's, check all of them.


I hope you dont have Spot Burn !


Athanasios
 

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Electohome could have put a couple of LEDs on the VIM bd that would have helped alot to find problems where there is no picture. No picture is usually caused by no G-2 voltage and spotkill being active. There are a few things that are monitored on the VIM and if bad the video output of the neck cards is turned off (SPOTKILL), the G-2 voltage is shut down (G2-INHIBIT), and the anode voltage shut off (EHT-INHIBIT).


On the VIM:


1, 2, 3 are signals from the neck cards. Normal operation the voltage is +2.5V the SPOTKILL, G2-INHIBIT, and EHT-INHIBIT are active and shut off the image.


4 is the SCANFAIL signal. Normally it is

5 is the BAND-SWITCH signal. Normally

6 is EHT-INHIBIT. This signal goes to the HVPS. Normally +2.5V the HV is shut off.


7 is SPOTKILL. This goes to the neck cards. You have to measure carefully here. Normal operation is +0.7V. It is not much higher than when normal. If active the output video of the neck cards is shut off.


8 is G2-INHIBIT. Normally +2.5V. If active the G-2 is shut off. SPOTKILL and G2-INHIBIT always work together.


You can save alot of board swapping, time, and effort if you can check these signals. They will help you narrow down the problem pretty efficiently.


Scott
 

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Discussion Starter · #14 ·
Thanks Scott, and now for the stupid question: how to do you physically measure those signals at the VIM with the PJ on? Is there any extension board so one can have the VIM physically accessible with the PJ on?
 

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Quote:
Originally Posted by antorsae /forum/post/15769823


Thanks Scott, and now for the stupid question: how to do you physically measure those signals at the VIM with the PJ on? Is there any extension board so one can have the VIM physically accessible with the PJ on?

On My Marque thread on curt's I think I listed the part you can order to make your own like I did, works quite well.

I had the same problem , and scott gave me the same info, It cam down to a bad VNB, the spot kill circuit on the VNB was causing it the send a Spot kill, G2 and EHT inhibit signals to activate the HVPS shut down. But in the process i blew out a VIM by sliping reading one of the pins..be carefull. I nevr got around to fixing the VIM but i replaced the VNB and the problem went away, it was son my Green tube . I bet its there Andre. I was getting and OVER-I signal that was higher than 2.5 on the green.


Athanasios
 
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