Cannot Transmit on SS3900

[happykipper]

Radio Make and Model: Superstar 3900
PCB Number:
PLL Number:
Test gear available: Oscilloscope / DMM
Symptoms: No transmission, unit does not Key up on signal meter

What is working: when Tx button is pressed the status LED changes to red to indicate transmission but the unit is not transmitting and the signal meter does not move on any of the frequencies or wavelengths. The unit is recieving ok and signal meter is working correctly for recieving but as I say nothing for transmission.

What has been tried: I read the forums that TR51 was troublesome on these units and I suspect it to be defective on my unit as well but when I removed it from the chassis I only have the idenifier of B827 on it and I searched for it and can't find it on the internet. Can anyone advise if they know an alternative Transistor, I suspect that the TIP146 may be a good alternative but I am not entirely sure and would like some guidance. I should point out that this is the Ranger PCB

Did it suddenly happen ?: Yes
Anything else that may be of help?:

[zodiac]

The Tip146 is a darlington PNP transistor, you could use a TIP2955 PNP 15A transistor at about 80p each depending on where you buy it from.
I don't think you are looking in the right place for the fault.
Before I go any further, what are the output transistors that are fitted in the radio or are they MOSFETS (IRF520) ?.