I have a NF that I rescued from an old barn, that will not boot up.

Both CPU leds 19 and 21 stay on and #20 blinks twice, stating a bad RAM chip. Since that's hard to find and soldered on, I want to rule out other stuff first.

I also measured voltages and all TPs turn out good, except TP6, which is 90 volts instead of 50. Is that because blanking is still on or is that something I must investigate?

Thanks! After trying some other stuff to prevent me from buying this IC I finally believe that replace the U8 will be the solution to this problem. I found a supplier and I'm going to order one asap.