Bottlehead Kits > Mainline

Almost - not quite. Help? [resolved]

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ALL212:
I'm pulling this out of the other thread I have so that it can be troubleshooting only.  Maybe it will be a shortcut for someone else to figure out an issue rather than read through the entire other thread.

Paul was helping me on this earlier but I'll summarize.

I have 6 LED's out of 8 lit, the other two were on initially but then went out at some point.

All resistance checks good.  All heaters come on.
Initial voltage checks were good and I'm sure all LED's lit on initial startup.  But I didn't continue to watch them all.  I finished the tests but hadn't adjusted voltage.  Upon 2nd power up only 6 LED's came on.  The A side back two LED's do not come on.  The C side all come on, back side quickly, front side after some seconds.

I switched left and right tubes and replaced the 12au7 - same.  Paul asked for some voltage checks:
Bad side        Good side
0A - 220           220
1B - 220           220
0B - 220           145

OB does not change on bad side.  OB does change on good side.

R1's are good, board completely reflowed, no shorts at the board that I can see.

Just before putting it back I put the magnifier on the socket.


 I had a cutoff shorting 5 to 6 on the A side socket.



I have the same results at the board after this but what may have died by shorting pins 5 and 6 at the socket?

Would I be safe by reversing the outside boards?  Or could I blow something else up in the process?

Doc B.:
Pin 6 is the cathode, pin 5 is the heater. If they were shorted, maybe the 2N2222A in the bias circuit on that side was blown.

ALL212:
I'll order up a couple from Mouser or Digikey.  Anything else you might suspect that I should order up?

Would it be worth the test to switch the boards?

Paul Birkeland:
You should also try swapping 6C45's between channels, just to rule out any damage to the tube itself. 

ALL212:
I think sometimes I forget the "thank you's".

Thanks guys!  Without your help I'd be driving blind here.

Parts are ordered.  When they get in I'll replace the 2n2222a's and see what happens.  I do have a spare pair of 6C45's also.

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