Soooo this amp is gonna keep me up all night! 5E9A went quiet

[Twosteps]

It's the one I asked about a power resistor(1/2w or more) in the other thread. Anyway it had some other problems

1. I made a stupid mistake(also in another thread) while checking power tubes plate voltages and shorted the PT, after that I kinda lost the headroom somehow and the sound changed a bit but otherwise all the measurements(voltages, resistance, current) indicated that the components are still fine...
2. So I checked the tubes which turned out my v1 started to develop microphonics so I thought that was it and went buy the new tube.
3. Today before I change the tube I decided that I want to change a power resistor as well so I drain the caps by connecting v1's pin 6 directly to ground then disconnect it
4. Before I change the resistor I decided to try the new tube first (it's v1-12ay7)... no sound.... put the old one in... no sound.....
5. The symptom seems to me like it should be in the signal path + I've noticed a possibly cold solder joint in for the signal so I retouched it.
6. The sound came back fuller and louder for two minutes and then diminished within seconds to nothing and won't come back again.
7. All the voltages still fine all the way to v1, all the joints are strong & shiny
8. I use nos reflektor 6v6s and one of them has the plastic base cracked from the heat after the first few times I fired the amp up but besides that they seem fine and been working properly.

The amp is quiet with minimum hum that I have to get close to the speaker to hear it, when I pull the jack off the guitar and tap the tip the noise is there but almost inaudible.

Any thoughts/suggestions?  my head is about to explode...

[Ritchie200]

Fenders are not exactly in my wheelhouse but looking at the original schematic, did they really put a shorting jack on the speaker out?

Back to your problem.  Please post your voltages.  The 6V6 base cracked?  Due to heat?  Do you have another set you can pop in there?  I am still wondering if there was damage done to your OP tubes when you were probing around earlier.

Jim

[Willabe]

...... did they really put a shorting jack on the speaker out?

Yes, just about every Fender that I recall has a shorting jack for the main speaker jack.

So if you play the amp with no speaker plugged in, it shorts the secondary output to ground. That's keeps the reflected high voltage, flyback voltage, from burning up the OT primary.

[Twosteps]

It's my ignorant guys, sorry, it's the tubes.. I've built a few amps already at this point but never once had this many tubes die at the same time so I literally didn't consider this possibility. 

Started with a microphonic V1 but that wasn't the cause for the signal loss it just create noises. It turns out the PI tube was on it's last leg, if I wiggle it I would get the signal back for like 10 seconds before it fade away to nothing again. It's my first time for experience this symptom. I decided to change all the preamp tubes including the trem just in case and now the 6v6 with a cracked base act up  not sure if it's the crack or the fact that I shorted it does it but I got a blinking/sparking light near the top of the tube if I hit the signal hard, never experience this before either. Although it still working and sounding fine but that clearly isn't a good sign so the OP tubes are gonna go too..

I've got a new rule for myself.. new build = fresh tubes

PS never know that about shorting jack for the speaker, cool!