MKIII help - any tube put in V1 doesn't fire up?

[av8or3]

Hi George!
Check to be sure all the pins are in the socket for the tube from the top and the bottom. You probably already tried wiggling the tube around a little but if not it might reveal a (or some ) loose pins. Inside the chassis you might find a loose/broken solder joint.
That's all I got at 2:00 AM (can't sleep)
See ya'
Jim

 

[Restless Rocks]

In the Mk III the V1 filaments are powered off a DC supply which also powers the R2 relay. Check to see if it will switch to R2. You can listen real close to hear the relay switch since there is no sound in the preamp. If you hear the relay clicking then your 6volt supply is good. If you have a meter; look for 6 vdc across pins 9 and 4. Like Jim says could be a socket problem. Didn't you have a loose tube socket problem before?