My 302 and PDA are no longer on speaking terms

On Saturday, my 302 and my PDA (5450) stopped talking to one another.
They've been together for about 18 months without any issues.

It started when the PDA complained about low battery power. I thought
that odd, but I still had GPS data. I could see that the PDA wasn't
charging by the absence of the orange light.

After I landed, I took the PDA to the truck to charge with the intent
to download my flight after charging for a while.
Now I can't connect to the 302 using Cambridge's file utility and I'm
not getting GPS data either. I can get the PDA to charge from the 302
intermittently. The connection is via a RAM cradle I got from Cumulus.
The flight software is mCU.

Initially, I suspected the PDA. However, I can still use a GPS card
that I have and I'm able to sync the PDA with my home machine. I
suppose I'll have to pull the 302 and test with a PC of some variety.
If that works, it must be the cradle.

The 302 connection is through com1 on the PDA. The GPS Card is com4.
Is there software that will let me test the com ports on the PDA? Does
it make sense that for I while I had data and no power and now it's
power (intermittently) and no data? The availability of power seems to
be a connection issue. But even, when charging, there is now no data
and no connection for file transfer.

I'd like to verify that the PDA can use com1 before pulling the 302.
That's a bit of a pain.

Doug