Vintage Synth Repair

Hi all,
The Wurlitzer group seems a little slow in traffic, so I give this 
group a shot.

My Wurlitzer 200(not 200A) measures roughly 5,4 V across the pick up, 
but it's supposed to be something like 147 V.

What could be causing this, a blown transistor?

It's strange, even though the low voltage, I still get sound from the 
speakers, how ever at quite low volume and weak timbres.
Also, in order to track down the problem I would need to measure the 
transformer voltages. There are four wires coming from the 
transformer; two reds, one blue and one yellow/red.

Where should i place the test leads of the voltage meter to get a 
correct reading?

Thanks in advance,
Einar