[a124ave]

I am having trouble with this stove not heating to desired temp. I found that the lower elements relay was not picking up after testing with meter. I removed this relay from board and tested with a 24vdc power supply and it was good. after further review looks a if a transistor is turning this on and off. I noticed that there is a smaller relay on board that turns the door locking latch on so I desided to swap is transistor with bottom heating elements one and now it turns on but will not shut off. Had oven turned to 350 and after a bit when first turning oven on it would shut off and than turn back on relay but went up to 450 and with no sign of shutting off. I figure transistor is still good because when I canceled oven the relay shut off. Question is does anyone have any other ideas or better a schematic of this stoves electrical system.