S/1020A, a non-export model 1986 was inspected April 14, so that serial # series could well have started early April. It would be cool to find the first one.
S/A1030A was also inspected on April 14th. I'd guess the start of this was around April 12th or 13th.
If you don't know how to discharge Filter caps, don't open the amp up. Filter caps are like battries and store voltage. but to discharge a Filter is pretty easy, you just need a wire with an alligator clip on each end and a large 1-2 watt resistor that's anywhere from 150-250 ohms. Put the resistor in one clip and the other clip to earth/ground(chassis). With the resistor end, hold it with an insulated pair of needle nose pilars in one hand and touch the positive terminal of each cap. It will drain the voltage to ground and keep you safe. Keep your other hand under your armpit or some place safely away from the chassis.
