Before I pull the speech board, I decided to test the voltages on the lamp driver board, SB-300, and VSU-100. Here’s what I measured.
Lamp Driver Board
TP1 4.5 v
TP3 4.5 v
SB-300
TP1 0 v
TP2 13.4 v
TP3 9.6 v
TP4 4.5 v
TP5 2.2 v
TP6 0 v
VSU-100
TP2 4.5 v
TP3 -9.3 v