I have a decent meter which has a basic hFE function, and most power transitors such as 2N 3055 can read between 20-120. I bought some MJ 15003s and when measured, one was 2 and the other 1, so I presumed them below spec and returned them. Anyone like to comment please about the function of hFE on h...

Thanks, although choosing the right spec is rather daunting in view of the high boost amps. The MAC charger has a 120 amp re-settable trip on the +ve output but it seems this was always tripping so they bridged it out which probably caused the demise of the diodes.

I'm attempting to repair a MAC (garage) battery charger/booster, 12/24v, 50/25A and 325/470A boost. Some of the diodes are short circuit, the markings on them are: T2K12-6 and T2D06-4 There are 8 diodes in two blocks of 4 feeding the positive output of the charger. I can't find, so far, any spec for...