[aprssig] troubleshoot MFJ-1270B?

[Chris Kantarjiev]

I just picked up a 1270B TNC, with the intent to turn it into a RELAY
APRS digipeater. When I apply power, I get lights on STA CON PWR,
and they all stay on. No serial communication so far. The ROM
inside is marked SYSTEM TNC 2 1.2.8 - 32K.

I've got some information here, but am wondering if this might be
a commonly known problem, before I start poking with the oscope?

Also, will this version of the ROM support RELAY operation, or 
should I be planning to upgrade? To what, UIDIGII?

Thanks,
chris