tube amp problem. loose tube maybe?

[bumcharge]

hi everyone! im new here, decided i would join and ask your opinions. so i got this tube amp a while ago. its called a jaguar. it worked when i first got it in alabama, but when i brought it back to florida, it stopped working. 4 of the 7 tubes light up (2 6v6's and 2 12AT7s) i have noticed that when you push the 5th tube (12AT7) to the side a little bit, it will work and the other 2 will light up and the amp will work for only a short time, i guess until the tube comes loose again. is this a socket problem or a problem with the tube? or is this something completely different? all help is greatly appreciated.

[Amp Kat]

Most definitely a tube socket problem. Sometimes you can take a pick and bring the pins closer together making a stronger contact and then sometimes poor soldering will run down inside the pin causing the tube not to seat all the way down in the socket. It will kinda cock to one side causing the amp to cut in and out. While playing you can wiggle the tube a certain way and it will play only until it vibratres loose again. Yeah the solution is to change the socket.

[Krong]

Before you try tightening up your socket take a few steps. Please don't put anything conductive in the tube socket! Use a sharpened chopstick or similar item to bend the conducters in the socket. Make sure and disconnect the amp from power and drain your caps before poking around. Nasty shocks are just that. Nasty.
If you don't have experience with high voltage please take your amp to an amp-tech and tell him your sockets are loose. Should be a quick fix with minimal cost.

[bumcharge]

thanks alot guys! i shall take it to the amp dude

[Regis]

Yeah, sounds like the sockets need retensioning.

[Rob Mercure]

Hey BC,

Do I have your symptom correctly? Three tubes don't light until you mess with just one of them and then all three light? If this is correct a bad socket may be a culprit (and you probably need em tightened and cleaned anyway) but your symptom sounds like a bad solder joint on the 12AT7 socket you're wiggling - if only the socket was defective it shouldn't affect the other tubes heater supply.
Can you solder? If so then simply remelting the connections at each of the 12AT7 pins should take care of your problem - although it is possible that the heater wire is broken at the socket and would need to be stripped and reconnected.
If you can't solder practice on scraps of wire until you are comfortable. This isn't a super critical soldering job but you'd be amazed how frustrated you'd be if you not only didn't correct the problem but duplicated it on all of the other 12AT7 socket pins.
And I assume that you've read the other advise and consulted RG Keen's and others primers for electronics beginners - and that's how we all started.

Rob