C4S Board Voltage Fail

[Paul Birkeland]

I'd ohm out the pins on the tube itself to see if pin 2 and pin 3 are shorted internally or if pin 7 and pin 8 are internally shorted.

[hughmann]

I ohmed out the pins on the tube, pin 2 to 7 0 ohm, pin 3 to 8 OL, pin 2 to 3 OL, pin 7 to 8 OL.

[Paul Birkeland]

OK, reading back through this you were saying pins 3 and 8 are reading as shorted, but these are connected with one of the jumpers, so this is OK.

With the tube removed, are you seeing 0 ohms between ground and pin 3 or pin 8 still? 

[hughmann]

With tube removed both pin 3 and 8 read OL.

[Paul Birkeland]

Maybe double check that those go back to 0 when you put the tube back in the socket. 

[hughmann]

Yes both go back to 0 ohm.

[Paul Birkeland]

You'd have to have a shorted tube for this to happen, and you should be able to measure that short by using your meter to check for continuity on the various combinations of pins 2, 7, 3, and 8 (pins 2 and 7 may read as shorted, which would be normal, but the rest should be open between all pairs).

[hughmann]

Checked continuity on pins 2,7,3,8. All pin combinations read open except 2-7 which you said may read as shorted. Does this mean that something is wrong with the socket ?