Communications Support Forums

Has anyone tracked down shorts on the 2.85V regulator on the XTL series main board ?

This goes to the main CPU chipset but I have three boards that had control head related failures ...blown control head fuse, bad control head, shorted zener on the SB9600 etc ...

SO I am hoping this is an I/O chip related short ...just wondering if anyone had tracked this to a typical ship that pops and shorts the 2.85 from a control head issue. ALready looked at the input mux but that's not it.

These are all 800 vintage boards as well.

This shows the typical 01/90 failure on power up ...radio not talking ...no CPU

Thanks