DX-55V no output

[Hawkeye351]

Got an old Galaxy DX - 55V on the desk today.

Issue:
No transmit output.

Evaluation:
Passthrough regulator had a hole blown in the center of it.
Driver collector lead was shorting with the base lead through sloppy solder work.

Replaced final, driver, passthrough regulator, AF regulator, modulation trans in passthrough section, D77, checked alignment and it was about spot on so I touched it up, checked solder joints and fixed what looked suspicious, receives great on both modes. Just still no output. Driver and final stay cold regardless how long you hold a key, the passthrough section stays cold regardless of how long you hold the key down.
Base of passthrough - 13.24v
Collector of passthrough - 5v
Emitter of passthrough - 13.45v

Driver (transmit)
Base - 0.01v
Collector - 4.78v
Emitter - 0v

Final (transmit)
Base - 0.01v
Collector - 4.78v
Emitter - 0v

Predriver tests fine in tester with a good Hfe.

I can see a full signal and hear audio when Transmitting on this radio and listening on another radio, but just nothing on watt meter or on radios meter. Transmit switching light does change to red when keying up.

This radio sat on the shelf of the latest old school TV/CB/ham tech that passed away for about 15yrs. The owner said when he grabbed it, that it had no final in it so I gave him one (and yes he knows how to remove and install a final). Well, he installed the final and immediately after keying up it started smoking around the driver. Now I have it on my desk and I've found that shorted collector lead and base lead of the driver before I did anything. I figured I may as well replace the driver, final and passthrough because that dead short probably weakened the parts. Then I found the passthrough had a hole blown in the center and knew it had been through some sort of catastrophic failure.

Any thoughts guys/gals?

 

[TM86]

Last time I had a problem like this (can hear TX audio on monitor radio, no meter deflection) it was a bad final. You know you're getting 27 MHz at some point in the TX chain, so start from the input of the predriver and follow the signal to see where it either disappears or even just gets smaller instead of bigger on a transistor output. Or you can work backwards from the final towards the predriver and see where the signal starts showing up. I'm assuming you have an o'scope.

Don't know enough about the radio to say if the voltages you posted are good or not. Even if some are low (again, I have no idea) I would expect at least a few watts out with all good parts in the TX chain.

 

[Hawkeye351]

I noticed my base voltages aren't correct, hmmm...although the collector is ok. Yea, gonna go the trace back route like you said, I'm trying to overthink it is why I can't figure it out. I've ran through this before, just can't remember what it turned out being.

Although my collector voltages on driver and final are in the ballpark, they still have less than a 1v increase than the passthrough collector. The voltage chart calls for a 1.04v increase on the driver and final collectors than the passthrough collector.

Gonna trace back like TM said.