Laney TT50H No Outout

[g1]

Or put the wire on the other side of the board.

Not sure how you would tie it to the heater trace, I guess it could go from one socket to another, as long as there are no other paths that the trace goes to.

[Enzo]

Or put the wire on the other side of the board.

[g1]

Now I realize that the socket mounts on this side of the board so the wire would prevent it from mounting flush. So the wire would have to run around the outside of the socket, rather than under it.

[g1]

The part you quoted in post #107 I was talking about your epoxy patch at R43.

Should have said now exposed trace next to hole is showing connection to all preamp tubes V1-V6 pins 4 & 5.

The exposed trace at V5 area should connect to V1-V6 pins 4 and 5 as it is a heater trace. So that is good.

The exposed trace next to hole is still connected to pin#4. Do I still need to run a jumper wire? If so, is it to connect pin#1 to exposed trace?

Replacing the exposed trace area with an insulated wire would be to prevent further arcing across the hole where the burn was. An arc will probably still want to jump across as there may still be some carbon from the burn. You can try to insulate the exposed trace and the hole, with nail polish/corona dope/expoxy, but if it arcs again it may burn the board to a point where it is much more difficult to repair.
If you scrape away the whole exposed portion near the hole, and run an insulated wire across the hole, it is highly unlikely that it would arc again. 18 gauge wire should be sufficient.
It would look something like this:

[ca7922303]

I think it is probably ok if it's not close to any other traces except it's own. Neither side is near ground potential like that heater trace is. There is not a big voltage difference between the 2 ends of R43 so it's not likely to arc over. If anything the carbon under it will be in parallel with R43 which would effectively reduce it's resistance value.
In any case it should not have anything to do with the hum balance pot issue.

Should have said now exposed trace next to hole is showing connection to all preamp tubes V1-V6 pins 4 & 5.

[ca7922303]

I think it is probably ok if it's not close to any other traces except it's own. Neither side is near ground potential like that heater trace is. There is not a big voltage difference between the 2 ends of R43 so it's not likely to arc over. If anything the carbon under it will be in parallel with R43 which would effectively reduce it's resistance value.
In any case it should not have anything to do with the hum balance pot issue.

Removed carbon by scraping off with knife and went thru to other side of board. No traces nearby. The exposed trace next to hole is still connected to pin#4. Do I still need to run a jumper wire? If so, is it to connect pin#1 to exposed trace?

[g1]

Any way of knowing if what I've done under R43 is good or could it be part of the issue still with the hum balance?

I think it is probably ok if it's not close to any other traces except it's own. Neither side is near ground potential like that heater trace is. There is not a big voltage difference between the 2 ends of R43 so it's not likely to arc over. If anything the carbon under it will be in parallel with R43 which would effectively reduce it's resistance value.
In any case it should not have anything to do with the hum balance pot issue.

[ca7922303]

The carbon must be removed. It is like a resistor and offers a path for the arc to strike. Epoxy won't do anything about that resistive path.
If you mean, can you use epoxy instead of corona dope once the carbon is removed? Yes it should work.
But having corona dope will be handy as you will likely have to deal with arcing again if you are working on tube amps.

Any way of knowing if what I've done under R43 is good or could it be part of the issue still with the hum balance?

[g1]

The carbon must be removed. It is like a resistor and offers a path for the arc to strike. Epoxy won't do anything about that resistive path.
If you mean, can you use epoxy instead of corona dope once the carbon is removed? Yes it should work.
But having corona dope will be handy as you will likely have to deal with arcing again if you are working on tube amps.

[ca7922303]

Yes the black carbon will need to be ground/cut/drilled out. Be careful not to cut into the traces on the other side of the board. Then some corona dope or brush on high voltage insulation over the repaired area and the damaged trace. Or grind out the damaged trace as well and run an insulated jumper wire across the break like The Dude mentioned.

How do you feel about epoxy over the burnt spot on the board like I did under R43 and a jumper wire?

[g1]

Yes the black carbon will need to be ground/cut/drilled out. Be careful not to cut into the traces on the other side of the board. Then some corona dope or brush on high voltage insulation over the repaired area and the damaged trace. Or grind out the damaged trace as well and run an insulated jumper wire across the break like The Dude mentioned.

[The Dude]

You'll have to grind out that burnt (blackened) part of the circuit board. Burnt circuit board can be conductive. It also looks like the trace may be burnt open (check continuity with meter). You may have to add a jumper wire.

[ca7922303]

That's pretty bad. The trace that has the green scraped away goes to pins 4 & 5 I guess. The arc from pin1 to that trace is what is putting the high voltage DC on the heater circuit and hum pot. The burnt area between pin1 and that exposed part of that trace will have to be drilled or cut out. The trace will have to be insulated again with nail polish or something. Or cut back and replaced with wire. The socket should clean up as the arc was not between pins.
Clean the board and socket up as well as you can and post pics.

V-5

[g1]

That's pretty bad. The trace that has the green scraped away goes to pins 4 & 5 I guess. The arc from pin1 to that trace is what is putting the high voltage DC on the heater circuit and hum pot. The burnt area between pin1 and that exposed part of that trace will have to be drilled or cut out. The trace will have to be insulated again with nail polish or something. Or cut back and replaced with wire. The socket should clean up as the arc was not between pins.
Clean the board and socket up as well as you can and post pics.

[ca7922303]

Have you had V5 tube socket removed yet? One of the pictures shows a bit of discoloration from the underside.
With such an odd problem it would be worth removing it and inspecting it and the board where it mounts.

V-5