[Dekatron]

While you are able to check the boards do measure all resistors and the electrolytic capacitors, replacing them as needed.

I've seen a lot of resistors on these boards increasing their resistance over the years (very few decreasing their resistance) and almost all of the electrolytic capacitors have dried out working more as a high ohms resistor than as a capacitor, some with cracked/dried seals.

However if you replace any resistors, and in some cases any electrolytic capacitors, you will have to re-calibrate the tester again.