6G2 Princeton amp?

[Tom Phillips]

sorry bout both treads. The two green filament windings for the heaters, has one going to the pilot light and the other is grounded to the chassis with the red and yellow center tap?

The 6G2 Princeton uses the chassis for one side of the heater circuit so it's normal for one green wire to be connected to the chassis. Red/Yel is HV center tap and that should be grounded.
I suggest that you proceed with disconnecting all the secondary wires and then if OK we hook one thing up at a time. Maybe make some resistance measurements first.

Let us know if the PT works OK and stays cool with the secondaries disconnected.

Please confirm that the Green / yellow stripe wire, if present, is NOT connected to anything. It's not used in a heater circuit like yours.

[chuckb]

When this amp came to me there were two heater wires as per usual. I found it a bit strange for one of the heater wires was grounded to the chassis along with thr red/yellowstripped CT?

[Tom Phillips]

When this amp came to me there were two heater wires as per usual. I found it a bit strange for one of the heater wires was grounded to the chassis along with thr red/yellowstripped CT?

Several of the old Fender designs used the chassis as one side of the heater circuit. Yours is one of them. That grounded side of the heater circuit would not cause your problem IF everything else was OK.

[chuckb]

I removed the heater windings from the pilot light. and tried it again and it blew another fuse.

[chuckb]

Well I removed the heater from ground and disconnected the heated wire from the pilot and it still blew a fuse.

[Tom Phillips]

OK.
Disconnect all the rest of the secondary wires including those attached to the chassis. Make sure none of them touch the chassis or each other and we will start from there.

[chuckb]

All the preamp tube pins #9's are grounded to the chassis. Only pins 4&5 have an actual winding on them. The 2 power sockets have a winding connected to pin #2, where 1,8,&7 are connected together and soldered to the chassis.

[chuckb]

ok I have all the secondary disconnected.

[chuckb]

I disconnected the pair of red wires and the pair of yellow 5v windings and the red/yellow striped CT wire. The only things connected now are the two black wires,one going to on/off switch and the other going to fuse. Plugged the amp in again and the fuse blew right away?

[chuckb]

Could the power cord be wired wrong of maybe a bad fuse holder?

[Tom Phillips]

All the preamp tube pins #9's are grounded to the chassis. Only pins 4&5 have an actual winding on them. The 2 power sockets have a winding connected to pin #2, where 1,8,&7 are connected together and soldered to the chassis.

That is all correct for your model amp.

I disconnected the pair of red wires and the pair of yellow 5v windings and the red/yellow striped CT wire. The only things connected now are the two black wires,one going to on/off switch and the other going to fuse. Plugged the amp in again and the fuse blew right away?

This is pointing to a bad PT but...

Could the power cord be wired wrong of maybe a bad fuse holder?

It’s remotely possible that something is shorted in the wiring before the PT. You can rule that out by disconnecting one black primary lead wire. Disconnect the one connected to the ON-OFF switch. If the fuse does not blow then I’m afraid that the problem is the PT itself. Why you had two PTs doing the same thing is either a coincidence or there is something else that stressed both PTs and caused them to fail.

Do the test I just described and we will know more.

[chuckb]

Hey guys, here are some more pics of the secondaries disconnected.

[chuckb]

Well I disconnected the black primary from the on/off switch and then inserted the fuse and it didn't blow. But without the primary disconnected it wouldn't blow anyways? This was a brand new tranny right out of the box.

[chuckb]

If it is the new tranny? what could've caused both to get ruined? I just installed it today and it may be gone already,wow!

[g1]

If it is the new tranny? what could've caused both to get ruined? I just installed it today and it may be gone already,wow!

If there was a fault that ruined the old transformer, and that fault was not repaired, then it would ruin the new transformer as well. How many fuses did the new one blow?
The other possibility is that a tube ruined the old transformer, and you received a bad replacement transformer. Maybe someone stuck a defective return on the shelf with the new ones and it got sent to you. Seems like too much of a coincidence to me, but you never know.
By the way, did you ever try the old transformer with all the secondaries disconnected? Probably worth a try before you junk it.