55
Troubleshooting Tips (continued)
With a nominal AC power input voltage (100, 115, or 230, depending on the country), the AC
voltages at the transformer secondary between P3-1 and P3-3 should be 41.3 Vrms.
With a cold (i.e.-room temperature) power transformer, you should expect primary and second-
ary resistances of:
For the 100 VAC version:
between P2-1 and P2-2: 41.8 Ohms
between P3-1 and P3-3: 6.9 Ohms
For the 115 VAC version:
between P2-1 and P2-2: 45.4 Ohms
between P3-1 and P3-3: 6.3 Ohms
For the 230/240 VAC version:
between P2-1 and P2-2: 195 Ohms
between P3-1 and P3-3: 7.1 Ohms
Other DC voltages that are of use in troubleshooting:
Turn On/Off Muting Circuit
Typical DC voltages after 2 seconds wake up
U15-1 Section not used
U15-2 +13.5
U15-3 -15.0
U15-4 +.15
U15-5 +3.2
U15-6 Section not used
U15-7 Section not used
U15-8 +7.5
U15-9 +13.5
U15-10 +7.5
U15-11 +9.7
U15-12 -15.0
U15-13 +13.5
U15-14 -13.9
Q1-collector -14.7
Power Supply
U13-1 +26.0
U14-2 -26.0
THEORY OF OPERATION