A2000 Problems
Max;
The Jumper is probably labeled J300 and is under the power supply chassis
(about front center of the power supply itself on the motherboard). I
believe that it is close to U300 (8520) but that is on memory which can be
none too good. Pins 1/2 jumpered is normal (TBASE from TICK) and 2/3 is
TBASE from _VSYNC). Tick comes from the power supply and provides a
better reference for the calendar clock but it is also susceptible to
failure.
-bill