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Post by Casethecorvetteman on Feb 24, 2016 5:14:16 GMT -5
Hi all, i swapped in two new tubes, and now ive got some serious arcing where the leads enter the splitter.
Im about to swap the splitter, but otherwise i cant see why it has started that now.
Any ideas?
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Post by gregstv on Feb 24, 2016 5:24:40 GMT -5
Usually its moisture. I was in Brisbane on the weekend and the humidity was 100% at 34deg. High humidity caused lot of arcing on CRT televisions back when I was servicing them. I would try cleaning everything with IPA and dry it all with hot air from a hair dryer. Maybe bake the splitter in the oven at 60deg for a couple of hours.
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Post by Casethecorvetteman on Feb 24, 2016 5:35:16 GMT -5
Swapped the splitter and its a heap worse. So unless both are stuffed, and they were both fine, then its got me buggered.
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Post by Casethecorvetteman on Feb 24, 2016 5:41:01 GMT -5
It seems to be rather servere at the blue lead, and the blue neck did let off a crack arc to the focus clamp.
I might try it without the blue connected and see what it does.
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Post by gregstv on Feb 24, 2016 5:46:26 GMT -5
Have you turned it on with the tubes disconnected? It could be moisture in the HV lead. It either has to much HV or the HV is traveling up the outside and arcing across due to moisture. You could try cleaning all the lead ends that go into the splitter with some CRC-226. Not much else I can think of at this stage. |
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Post by Casethecorvetteman on Feb 24, 2016 6:52:09 GMT -5
Ive cleaned them all, replaced the quad because the red lead arced to it, the new one arcs in the exact same spot where it enters the splitter, i cut the end off the red lead above where it arced and resoldered the end, it arced again same place. Green lead does not arc at all.
I spose itll just keep arcing now until i replace everything there will it?
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Post by Casethecorvetteman on Feb 24, 2016 7:32:33 GMT -5
The red tube is the original from the set that it left the factory with, about 7,300 hours on it. Never an issue before. Lead arcs where it enters the splitter.
The Blue came from Curt and is allegedly 'new', but it is certainly not. There is no question its been used, not much though. Lead arcs ALOT where it enters the splitter.
The Green came from my Barco Reality 909 and has been in that set for about 300 hours, and has a total of 22,780 or so hours on it. I cant see it arc anywhere.
Splitter that came with the 909 has been in the set for 8 months, clean as clean gets, when running i can see slight blue glows at certain points on that little board it has on top of it. Little black lead seems to arc to the terminal beside it.
The red and blue have been sitting here in my cinema room for about 12 months or so.
I used a heat gun to heat up the splitter and the lead from the quad til they were quite warm, no tubes connected, lead still arcs where it enters the splitter.
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Post by dummyload on Feb 24, 2016 11:46:20 GMT -5
I would not fire up the unit without any tube connected to hv, the hv circuit might not work properly without any load to it , I'm not sure but would not risk damage to quad ,splitter are both.
Is the blue glow on the board where the hv feedback coax is connected ? Thats not good.
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Post by Casethecorvetteman on Feb 24, 2016 12:05:27 GMT -5
Yes, there is a blue glow there. What would make it do that? The HV lead going to one of the tubes arced to the ground side of that. It also arcs all around the potting compound where the quad lead goes in.
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Post by dummyload on Feb 24, 2016 14:50:34 GMT -5
Sounds like a bad splitter (but again?) Just a long shot is the small feedback coax reconnected correctly on the current splitter ,and check with multimeter if the ground of the coax on the splitter is still 0 ohm to chasis. The feedback signal is calibrated with the trimmer on the splitter to be 1/1000 of the output .(DON'T TOUCH THAT TRIMMER) so when there is something wrong there it wil result in to high or to low hv output. |
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Post by gregstv on Feb 24, 2016 14:53:20 GMT -5
I have 4 splitters that arc on the little board on top of the splitter. They all shut down the HV. You may have two dud splitters. Greg E recommends baking the quads and splitters before fitting to avoid arcing that kills them. I will find his email and toward it to you. Do you have anymore splitters?
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Post by dummyload on Feb 24, 2016 15:17:55 GMT -5
If you have the equipment to measure the hv output and it's value is normal then you know electronic circuits are o.k. and the problem is with degraded isolation, kabels, potting in combination with humidity (as gregstv already suggested) |
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Post by Casethecorvetteman on Feb 24, 2016 19:44:57 GMT -5
I have 4 splitters that arc on the little board on top of the splitter. They all shut down the HV. You may have two dud splitters. Greg E recommends baking the quads and splitters before fitting to avoid arcing that kills them. I will find his email and toward it to you. Do you have anymore splitters? No more splitters. That one was working fine right before i shut it down it swap tubes. have you got a spare? |
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Post by Casethecorvetteman on Feb 24, 2016 19:48:02 GMT -5
If you have the equipment to measure the hv output and it's value is normal then you know electronic circuits are o.k. and the problem is with degraded isolation, kabels, potting in combination with humidity (as gregstv already suggested) Well the circuits are working as they should or it would shut down apparently, but it continues to run and displays an image. There is some shaking caused by the arcing, but apart from that the 25 seconds of image i viewed on the tube faces was perfect |
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Post by Casethecorvetteman on Feb 24, 2016 19:51:02 GMT -5
Sounds like a bad splitter (but again?) Just a long shot is the small feedback coax reconnected correctly on the current splitter ,and check with multimeter if the ground of the coax on the splitter is still 0 ohm to chasis. The feedback signal is calibrated with the trimmer on the splitter to be 1/1000 of the output .(DON'T TOUCH THAT TRIMMER) so when there is something wrong there it wil result in to high or to low hv output. Yeah was one of my first checks, zero ohms to chassis on the little while lead ground side. The trim pot is sealed and cant be adjusted, but i dont randomly adjust pots anyway unless i have a procedure infront of me to follow. |
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