SR-655hp transmit issues

[Trainman 8274]

Howdy,

A friend brought me a Stryker 655 that doesn't transmit. He was told it needed finals. He bought IRF520N finals for it. I 'checked it and it had no transmit or modulation, so I changed all 4 mosfets. So, It still doesn't transmit. I can turn the AM power down and get it to key up and show power out on a watt meter, but no modulation on a scope and just a carrier with noise on a monitor radio. I'll check PA mode tomorrow. I'm pretty sure I did, but don't remember the results. I'm not an SMD person, but if its something like the regulator or something, I can change that. Any help would be appreciated.

Thanks,

Stuart

 

[sp5it]

What is input and output voltage on pass regulator transistor?
AM:
USB:

Mike

 

[Trainman 8274]

What is input and output voltage on pass regulator transistor?
AM:
USB:

Mike

Good morning Mike,

The 655 is AM/FM. Which transistor will this be?

Thanks,

Stuart

 

[Trainman 8274]

Hi Mike,

Q55 which looks like the voltage regulator has 13.1V coming in and 6.86V on the center pin not transmitting and 6.62V transmitting. That should be 8V, shouldn't it?

Thanks,

Stuart