Problems persist

[Knightstick]

Hello all. I have gone through the wires on my crack from the power input to the transformer, and reflowed all joints. I also checked and reflowed all green wire terminals. The amps still doing the same thing. It will play for about 20 minutes then both tubes go out. I then unplug it, and plug it back in about 5 minutes later and the same cycle begins again. Seems like some kind of issue with heat. Any help would be awesome! Thanks in advance.

[kgoss]

Post pictures especially around the heatsink. If you did not install that properly it might not becdoing its job. Also do a voltage check when the amp stops working. The problem seems repeatable.

[Knightstick]

Thank you for your response! I can definitely do some voltage checks but I haven't installed the speedball. It's still the stock crack. It wouldn't be the transformer would it? As long as that isn't gone I'm considering breaking it all down to do a better job.

[Paul Birkeland]

You need to do voltage checks once the amp has powered itself off.  In particular the DC voltage at terminal 2 would be good to know.  It will either be 0V or close to 200V when the tubes aren't glowing. 

[Knightstick]

I got up this morning, and turned my amp back on. It has been running for approximately an hour and a half, and it sounds good. The only thing I did was to turn the power off yesterday when the tubes went out, and turn it on today. I suppose I got some cold solder joints? I did do a very poor job with soldering and rushed the build against wise advice.

[Paul Birkeland]

Yes, I suspect you have a wire that either isn't captured by solder, or a cold joint.

[Knightstick]

Thanks for your help sir!