Adding PL to MSR2000

[VE9PTR]

Hello All,
I'm trying to add a PL tone to the input (and output) of our local ham radio vhf repeater. The repeater was working when I began, but after installing the PL card and making the required jumper changes (at least according to the tables I've found) I now have a non-working repeater!

I believe it now has a ground issue somewhere in the PTT ciruit but this is the first MSR I've worked on and have spent hours trying to figure it out without any luck and need some help.

The receiver seems fine (audio and COR indication when signal with PL applied) but this is where it goes south. The repeater is tied to a RLC controller (DSP404) which I don't think is the issue as I tried another RLC controller and it acted the same....so, what it is doing is when the COS is active, the controller forces the PTT and the transmitter comes on BUT you only get a very short burst of the audio (I'm guessing 1/4 sec) then silence, with the tx still on. The odd part is that if I disconnect the PTT line from the controller, with the repeater still keyed, the audio is fine. It seems like the repeater is grounding out the audio somehow to the PTT circuit. In fact, if I disconnect the controller completely the repeater still keys up when the squelch is broken, and PL is present. I've checked and re-checked jumpers and cards and can't seem to find anything obvious. My next move would be to create a whole new set of cards and try them...any suggestions????

Cards are: PL (TRN5073APR), SQ Gate (TRN5324), Station Control (TRN5321a) & R1 Audio (TRN5069a).

Thanks for any advice,
Pete

[desperado]

if you are getting a burst of audio then nothing it almost sounds like you are incorrectly detecting the PL. Once the PL card see's a "wrong" PL it mutes but you have a weird path keying the TX off the COR that shouldn't exist.

Go back and verify that the PL is right on the card for RX.
PL can be finicky. If you are not very close to the correct PL tone, it don't work.
It could also be a bad PL decoder on the PL card. With the age of that hardware, it could have drifted and be between.
You might get a service monitor and sweep up and down near the programmed PL and see if that gets the RX working correctly.