Could anyone give a way to test transformers (for computer equipment , modems etc.) My Plustek scanner gave up the ghost recently and so I checked as best I could and after trying the tip polarity test, getting no reading assummed the trannie was dead. Just to check, I tried my radio scanner trannie - gave 15v tip positive. Tried two other similar trannies with no readings so I was very supprised when I plugged them into a modem and the lights came on. What do I do to test if a trannie is good other than plugging them into tackle they were not designed for? Any ideas?