Author Topic: No lights on CPU 039 board (Read 4204 times)

Tilt · « **Reply #20 on:** January 05, 2021, 10:00:19 am »

That's what I would do. You don't need a 3903 board though, a 3902 will work. The difference between the two is the 3903 has the telltale battery and the 3902 doesn't. You're actually much better off not having the battery so you don't have to worry about future leaking and corrosion.

gposing · « **Reply #21 on:** January 05, 2021, 11:11:48 am »

New CPU ordered. Fingers crossed.

Tilt · « **Reply #22 on:** January 05, 2021, 11:42:39 am »

Ok good luck. Did your old varta battery show signs of corrosion? If so, that may have been what killed it.

gposing · « **Reply #23 on:** January 11, 2021, 06:27:48 pm »

Well i got my new cpu and I have the same problem No power to the mother board. There is a red led on the mother board it never comes on. I did the same test with the new board. disconnected all wires to the mother board except for the power in the lower right hand corner. still no lights on the board. I tested the power to the board and I found 13v on it. my next guess would be the mother board or is there a fuse somewhere I am missing.

Tilt · « **Reply #24 on:** January 11, 2021, 06:40:43 pm »

The LED on the motherboard doesn't illuminate, but that doesn't mean the motherboard isn't the problem. It would be kind of unusual though. Check both the +13 and +25 at J13 on the motherboard. That's the connection from the power supply. Red wire should be +13VDC, Orange should +25VDC. There aren't any fuses on the 3902 motherboard. If the inputs to the motherboard from your power supply are good then I'd pull the motherboard out and inspect it for signs of damage, such as a burn trace.