Just got my 1 yr old 6255 spektrum Rx back out of the parts bin and it doesnt work ! when I plug in a power source 5 to 8 volts (tried them all) it wont light up or go into bind mode. Does anyone have an idea whats up ?

Polarity correct? Ive plugged them in backwards before.
Black wire towards the top?

checked and double checked . all my other Rx's are working off the same battery I tested this Rx with. Seems strange.