2 of the 4 Diodes on the rectifier circuit in the RF box on my front loader NES have gone bad and need replacing, does anybody know what rating/type of diodes i can use for replacement please?
The 1N4001 would work, since the average current is < 1A, but I would probably use something like a 1N5391 (1.5A) for extra margin. I also strongly recommend you change all 4 diodes since it looks like one half of the bridge went short and the resulting heat would tend to cook the other diodes even if they test OK at the moment. In fact, you can use anything from 1N4001-1N4007 or 1N5391 to 1N5399 - the last digit is the breakdown voltage and using a higher breakdown part in place of a lower breakdown one is generally OK.
While you're in there you should change out the capacitors. I'm starting to see them fail on NES consoles with the most obvious symptom being a lack of sound amplification. No idea what would happen with the caps for power.
