I was working on a Jenn-Air Mod# JJW9630AAB oven with no display on the clock, so I replaced the clock. When I first flipped the breaker back on the display was better but not great. Then it got dimmer and dimmer until it was as bad as the old clock.
My readings at the J1 connector are:
pin 1 to pin 2 = 12VDC (I think this powers the display)
pin 3 to pin 4 = 21.3 VAC (not sure what this powers)