Royce 619 troubleshooting needed

I own a Royce 619 40 channel from the 70’s. It lights up but only gives off a low level static. It has no receive and no transmit, when mic is keyed TX light comes on but no output. The thing is Its new, It sat in the box for 40+ years on a shelf. I tried testing it on a good working system so I know it’s the radio. Any ideas or someone who still repairs?
Thanks

Royce manufactured what I would consider to be a “middle of the road”, but good quality transceiver.

I’d suspect any of three items to be the culprit. First, look at the solder joints on the underside of the printed circuit board, see if there are any incomplete joints, or solder bridges. Second, look for leakage around all electrolytic capacitors, and plan on replacing all of them. Third, I’d troubleshoot the power supply, then the RF-in and RF-out sections which junction with the antenna connection.

Also look to see that the chassis grounds are intact.