Fender princeton reverb transformer problem

[Doug]

This is the first time I've ever had a transformer problem. Amp was blowing fuses. With power tubes removed, fuse held, transformer made a sizzling sound. Checked the GEOFEX troubleshooting, wanted to make sure my transformer testing was correct.
Measured resistance between pins 4 and 6 on the rectifier socket. (tube removed) read 266 ohms (below 1K is good?)
pin 4 to ground 88 ohms (should be 1M or more?)
pin 6 to ground 179 ohms (should be 1M or more?)
Am I doing this correctly? Are pins 4 and 6 the primaries?
Again this is my first transformer diagnosis, the SIZZLING steered me that direction.

[Enzo]

If transformers sizzle, bubble, or scream in the night, they are pretty well shot.

The primary is the input side of a transformer. In the case of a power transformer that is the side that plugs into the wall. The secondaries are the windings for the heaters and the high voltage.

With the recto tube removed, you are measuring at pins 4 and 6 the transformer secondary winding resistance. From end to end you got 266 ohms. From either end you got 179 or 88 ohms to ground. SInce the center tap of that winding is grounded, this makes sense. Note how those two number add up to the other. Seems a little lopsided to me, but it is potentialy possible for those readings. But with the power tubes pulled and the rectifier tube pulled, if that power tranny gets hot all by itself, or starts bubbling, replace it.