If you tested with different power supply units you can do following tests:
1) remove RAM and try to boot without HDD
2) measure 3,3V voltage on the center pin of voltage regulator
3) try to test on another A1200 motherboard
If no results and 3,3V is ok; well, you have broken turbo card :-(
You can send to someone for repair (I can do so but other persons on this Forum can do this job as well). But none will give you 100% guarantee that card will be fixed.
If IC's are not electrically damaged the chances that card can be repaired is about 95%
Cheers,
Stan