Haunted Blues Junior

[kbperry810]

Okay, ready to pull my hair out over this one...

Friend talked me into installing Bill M modes into his BJ; so did the job, back together, amp sounds great. He took it home, played it a bit, then called me up saying it was crackling and cutting in/out... so get it back here, take it apart; found a spot where it looks like the solder pad had came up a bit; so got that fixed up... turn the amp back on and it sounds great, until...

...until you touch the MV; if you tweaked the MV a bit, it would crackle and fade out. Power it off, back on, sounds great again, until you turn the MV a bit, then same thing. After some poking and prodding I ended up replacing the MV pot...

...okay, MV pot part arrives, get it installed, amp back together, go to power it on and nothing... and I see the problem right away. V3 is the only tube with lit filaments; V1, V2, and the EL84's are all dark, even dimmed the lights in the room to confirm there is nothing glowing except v3. Did some quick tube swapping around with known good tubes, and same result, only v3 lights. Check voltage on the filament lines, and have around 3.4 volts on each.

I'm feeling fairly flustered and confused at the moment, so thought I'd step away from the amp and post this up here for thoughts.

Maybe the socket pins have separated from the board? I should go check that... but for that to happen on 4 out of 5 sockets when I never pulled that board section out? Ugh.

[rock_mumbles]

Resolder everything you can get to

[Randall]

Resolder everything you can get to

I'd hit all the ribbon cable solder joints. Notorious.

[kbperry810]

That will be my game plan for today... going to check the top of the sockets to the back of the board to check for any breaks there; then if that checks good the next step will be checking all the ribbon connections, along with some re-soldering.

[DonMoose]

That will be my game plan for today... going to check the top of the sockets to the back of the board to check for any breaks there; then if that checks good the next step will be checking all the ribbon connections, along with some re-soldering.

Check from top-of-socket to far-end-of-trace - the socket pins aren't likely to break, but the traces are. Though socket pins may have opened up a bit. Not sure how to check that in a meaningful way.

- hope this helps!