Laney TT50H No Outout

[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?

[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.

[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:

[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.

[Enzo]

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

[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]

One end could be tacked to the socket leg. Of course just doing what you said earlier, run the wire around the socket also works. Meanwhile, other side. One end to socket leg, other end to something else connected to that trace. Perhaps another socket. But in general, I have a few tiny drills, like #56 and #62, and a small hole in the pc board for the wire end, placed next to the trace, and solder it to it.

[g1]

in general, I have a few tiny drills, like #56 and #62, and a small hole in the pc board for the wire end, placed next to the trace, and solder it to it.

I think that would be the best bet, it's too long of a run to the next socket. A small hole drilled next to the trace just outside the socket with the burn, a short piece of wire from the trace to the solder side pin4 connection.

[ca7922303]

I think that would be the best bet, it's too long of a run to the next socket. A small hole drilled next to the trace just outside the socket with the burn, a short piece of wire from the trace to the solder side pin4 connection.

Any reason why this wouldn't work?

[g1]

Any reason why this wouldn't work?

Does the socket go as far down to the board as it should? I thought it might be flush mount so I was worried the jumper would keep it from going all the way down to the board.
Then the pins might not go as far through the board as needed, and the solder joints would be more likely to break whenever the tube was inserted.

If the socket goes down as close to the board is it was without the jumper wire, you should be ok like that.

[ca7922303]

Does the socket go as far down to the board as it should? I thought it might be flush mount so I was worried the jumper would keep it from going all the way down to the board.
Then the pins might not go as far through the board as needed, and the solder joints would be more likely to break whenever the tube was inserted.

If the socket goes down as close to the board is it was without the jumper wire, you should be ok like that.

Yes, that's as far down as it goes and still not touching the jumper wire. Thanks for your help.

[ca7922303]

Does the socket go as far down to the board as it should? I thought it might be flush mount so I was worried the jumper would keep it from going all the way down to the board.
Then the pins might not go as far through the board as needed, and the solder joints would be more likely to break whenever the tube was inserted.

If the socket goes down as close to the board is it was without the jumper wire, you should be ok like that.

Got it all put together and at 163vdc @ R43, I'm getting 60mvdc @ both pins of hum balance pot. Stopped there to see what you make of it.

[g1]

That's on the variac? Sounds good so far. If going up with the variac and the reading on the hum balance pot stays in the mV rather than volts, you should be ok I think.

[ca7922303]

That's on the variac? Sounds good so far. If going up with the variac and the reading on the hum balance pot stays in the mV rather than volts, you should be ok I think.

Yes, Variac was at 40v, R43(160vdc), hum balance pot(60mvdc).

[ca7922303]

That's on the variac? Sounds good so far. If going up with the variac and the reading on the hum balance pot stays in the mV rather than volts, you should be ok I think.

Ran Variac up to 104v, R43@448vdc, getting 216mv/78mv at hum balance pins. Without a Variac, full power, R43 @ 472vdc, hum balance pins 237/77 mvdc.