Apparently, this mod works with A600`s too.

I was looking through the A1200 schematics the other day, and noticed a section marked 'optional'. The bloody cheapskates at Commodore liked cutting costs,so it never was an option, but the motherboard layout stayed the same, just without these 5 components!! All it did was power an additional LED when the PCMCIA port was accessed...and you can never have enough flashing LEDs ;)

Parts needed..
1x 10K resistor
1x 4.7K resistor
1x 330R Resistor (or whatever you need to limit the current to the LED)
1x Low power PNP transistor eg.BC558 or 2N3906 (a medium power PNP such as BC327 will do..it`s all I had at the time!)
1x LED
1x Pin

The parts don`t have to be surface mount, normal through hole parts will work as there is plenty of space to bend their legs to the solder pads.

Where do they go?
All the missing parts are soldered in place near CN14 (The LED connector).
Solder the 10K resistor to the spot where R637 should be, the 4.7K goes to the R638 spot, and the transistor goes where Q634 should be.

Take care to check the leads of the transistor, matching them to the picture below. I wont give transistor pinouts, as they are available in many different packages, with differing pinouts..so check with the suppliers/manufacturers datasheet.

The pin is soldered where the missing pin 4 should be on CN14, to provide connection to an LED.If you don`t have a spare pin, then you can always solder a flying lead to the underside of pin 4.

The remaining resistor is soldered in series in the positive wire to the LED. Now all you need to do is stick the LED somewhere on your case, and wire it to CN14.

To test, just insert a card and startup PrepCard(in Workbench/Tools) and the LED should flash. If not, check the LED isn`t wired back to front !
NB. You must have a PCMCIA card inserted ..accessing the memory space alone won`t light the LED.

Disclaimer
Modify your A1200 at your own risk. This is Commodore`s design, not mine..and I take no responsibility if you screw it up and blow up your computer.