1971 Philco color Tube Hybrid

[Lain94]

Originally Posted by Electronic M

Clean it with rubbing alcohol or goof off, file or scrape off any remaining carbonization of the material, apply some silicone over the arc point and let it cure.

It sounds like a good plan. I also am getting a product called "Super Corona Dope" apparantly it is a product meant for very high voltage stuff like what I am working with.

[Lain94]

Ok well, I cleaned up the connector, the plastic nipple cup for the HV tube, applied the corona dope generously ect. But still having the same issue of arcing in the HV metal box. To be fair I did not directly witness it, only saw the flashing coming out from the translucent plastic tube holder for the HV rect tube 3DC3 which hangs upside down weirdly.

Flyback physically looks fine but I am starting to wonder if the damper and/or the hv rect tube are bad as well. I read the damper tube if bad can actually kill the horizontal output tube too. The first tube that was arcing internally was the horizonal output tube which i replaced with a NOS one and that issue had went away which is when this new issue has started.

Any overt signs to look for with a bad damper or HV rect. It is just weird to me why it is arcing still. Would it be worth getting a known good damper and HV rect. tube and swapping just to see what happens?

The arcing seems to happen within seconds of the tv being turned on. All tubes do glow.

[old_tv_nut]

Apparently you cleaned and insulated to cap connector, but didn't do anything around the base of the tube? If that's correct, do an inspection of the base for problems.

[zeno]

Take the whole thing apart. Clean the cup, socket, wires with 91% alky.
Look for pin holes & carbon traces on the cup. Check the filament
winding also. It is at full HV potential & a common place to arc.
Last be sure the HV is in spec. If it runs high it will start arcing
soon again & cause other headaches.

73 Zeno
LFOD !

[Lain94]

Originally Posted by zeno

Take the whole thing apart. Clean the cup, socket, wires with 91% alky.
Look for pin holes & carbon traces on the cup. Check the filament
winding also. It is at full HV potential & a common place to arc.
Last be sure the HV is in spec. If it runs high it will start arcing
soon again & cause other headaches.

73 Zeno
LFOD !

I think the arcing is actually happening where the wires go into the plastic tube socket as shown in a screen shot of the issue occurring. Any tips on how to open it up? The plastic base is riveted onto the metal cage and the top cover of the plastic socket might be glued in. Not sure how to get it off.

Also what in the heck is this bare copper wire that is dangling from the side of the HV box?

https://imgur.com/a/aD58QCV

[zeno]

Wire looks like its to dress the wire bundle, yoke wires ?
Top cap should pop off.
Cup would need to be drilled off. Do last if needed.
Try removing the cover & running it in a blacked out room to see arc.
Set has a focus divider, white block behind the cage. Those can
crack & arc.

Zeno

[Lain94]

Originally Posted by zeno

Wire looks like its to dress the wire bundle, yoke wires ?
Top cap should pop off.
Cup would need to be drilled off. Do last if needed.
Try removing the cover & running it in a blacked out room to see arc.
Set has a focus divider, white block behind the cage. Those can
crack & arc.

Zeno

I removed the top plastic cap to see the pins where the red and white wires go. First I hear the high pitched CRT whine seconds after powering it on. Then the arcing starts. The arcing is still happening and clearly is jumping between the red and wires across the pins they connect to. Also there appears to be a second spark happening right after the first bright one which is seen flying off bottom part of the metal chassis (near the HV metal box perhaps)

https://imgur.com/a/UgnZ2GO

[zeno]

There is clearly brown greasy looking crud on the socket.
See if you can clean it up with a swab & 91% alky. Be sure to discharge HV first but the divider probably bleeds it off anyhows.
You may want to search e-bay for a NOS HV cup.

73 Zeno
LFOD !

[Lain94]

Originally Posted by zeno

There is clearly brown greasy looking crud on the socket.
See if you can clean it up with a swab & 91% alky. Be sure to discharge HV first but the divider probably bleeds it off anyhows.
You may want to search e-bay for a NOS HV cup.

73 Zeno
LFOD !

Will do. Any advice about the metal rivets? Is it avoidable to drill them off or is that they only way if I need to replace the HV cup?

[Electronic M]

Originally Posted by Lain94

Will do. Any advice about the metal rivets? Is it avoidable to drill them off or is that they only way if I need to replace the HV cup?

The cup looks like you can easily get away cleaning it. Even if he worst cup I encountered in a 13" Zenith color that had arced through the cup I was able to clean it with goof off drill out the carbon in the hole the arcing made them fill the hole with sensor safe silicone and it's held up for years.

There's several ways to remove rivits such as drilling, grinding the heads off with a Dremel (good for cases where you want to temporarily remove a rivited item), cutting the shaft of the rivit if the item it's securing is gone and it's loose in it's hole.
I'd leave the socket attached for cleaning.

[Lain94]

Originally Posted by Electronic M

The cup looks like you can easily get away cleaning it. Even if he worst cup I encountered in a 13" Zenith color that had arced through the cup I was able to clean it with goof off drill out the carbon in the hole the arcing made them fill the hole with sensor safe silicone and it's held up for years.

There's several ways to remove rivits such as drilling, grinding the heads off with a Dremel (good for cases where you want to temporarily remove a rivited item), cutting the shaft of the rivit if the item it's securing is gone and it's loose in it's hole.
I'd leave the socket attached for cleaning.

On a side note, does anyone have the schematic for this tv? I have one schematic of it but it is from an old magazine and the resolution of the scan is not so good. I can barely read most if any of the schematic. I am going to do a recap of all the electrolytics while I am working on this tv after I fix the primary issue it has. I am sure the caps are leaky given the age of the tv.

[Lain94]

A bit of an update. I tried using iso to clean up the gunk on the HV cup for the tube and also used a generous amount of super corona dope. I am still having the arcing issue however. I am not sure if this is because of a grounding issue, the voltage being too high, a bad CRT, flyback, transformer, or if there is still some hole somewhere? I am honestly stumped right now.

[Electronic M]

Originally Posted by Lain94

A bit of an update. I tried using iso to clean up the gunk on the HV cup for the tube and also used a generous amount of super corona dope. I am still having the arcing issue however. I am not sure if this is because of a grounding issue, the voltage being too high, a bad CRT, flyback, transformer, or if there is still some hole somewhere? I am honestly stumped right now.

Well you can get an HV probe/meter and check the HV to rule that out. If the fly isn't getting hot and you have enough HV and deflection then its probably OK.

CRT grounding can be checked by eye and by resistance.

You can investigate the source of the sound further by getting a few feet of insulative plastic or rubber hose sticking one end in your ear and probing around for the loudest arcing sound with the other end like how a doctor would use a stethoscope.

Lastly don't put corona dope on something that you haven't gotten completely spotless. Dirt can be conductive, stains in the plastic can be carbon tracking, and carbon tracking must be completely removed before corona dope or silicone is laid down (even if it means taking a Dremel to the plastic and grinding it away) or else the arcing will just penetrate the thin layer of dope and resume it's normal carbon track.
When Isopropyl (rubbing) alcohol fails I next use GoofOff to clean off residual dirt....That stuff will slowly melt the outermost layer of plastic or rubber so if GoofOff don't get it clean it's Dremel time.

[Lain94]

While I was cleaning the tube sockets in the tv, I noticed a rattling sound from the horizontal output tube and noticed a loose piece of metal or filament was loose and rolling around. I attached a photo of it.

This is pretty frustrating because this horizontal output tube was purchased recently by me to replace the bad horizontal output tube the tv had with it.. The horizontal tube was not originally making a rattling sound nor had any loose bits in it when I had put it into the tv a month ago.

What could have happened? Could it have been vibrations or just bad luck? The tv was sitting on an old hardwood floor and vibrations travel easily through the floor when one walks around the house.

I am guessing this means the tube is bad or is unsafe to use now and I should get yet another replacement?

It looks like a little metal "tab" instead of a filament though.

https://imgur.com/a/ChYo70o

[Electronic M]

I can't really tell what it is. If you think it's metal then it probably is a danger. If it looks like glass or mica wafer (insulator materials) I usually keep running the tube...A chunck of insulator won't hurt anything, but a conductor can short things.