On Mon, 25 Nov 2013 14:54:56 -0700, Tony Hwang wrote:

If the control board does not solve the problem, then what?

Normally I don't throw parts at a problem.

But,
1. The transformer is clearly bad (open secondary).
So I have one on order and another coming in via warranty repair.
But, this is not mandatory for operation anyway.

2. The battery protection board clearly has a capacitor that has
melted leads on the underside. What I plan on doing there is
replacing the capacitor; but this is not an important board
for operation either.

3. When I put 12VDC to the main circuit board, it beeps a long
beep, and nothing else happens.

So, what does that tell me?

It *could* be that the board simply needs to be "reset", so, I'll
read all the manuals I found he
http://www.alarmhow.net/manuals/Radionics/D2212/

Or, it could be that the battery is bad. So, I'll charge the battery
and test it under load, to see if that's the problem (but I don't
think it is simply because the board is only drawing 100ma at 12VDC).

Or, it could be that the D2212B circuit board is bad. If that's the
case, I'll try to troubleshoot it by testing where the power goes
when I plug in the battery.

But, the board should only cost about $100 so it's not all that bad
to just replace it. Bosch says they have plenty in stock, so, all I
have to do is find someone who will sell them to me as a pass through:

Bosch sells the board to ADI or to Anixer, who then sells it to a
pass-through contractor who sells it to me.

If the board doesn't work, then I'd be surprised; but it would then
be time to replace the entire shebang.