Parts And Components Trouble Shooting - Intelligent UFM-B Maintenance Manual

3.2 PARTS AND COMPONENTS TROUBLE SHOOTING

3.2.1 Power Supply Checks
3.2.1.1 Relevant parts:
Main Board (FM-12-X)
Q1 (A1515)
Q2 (A733)
U5 (IC 4027)
U11(AIC 1722-5.0)
Q5 (C1061)
Q4 (C945)
ZD1(ZENER 8.2V)
R51(1.2R 1/2W)
DC JACK
BATTERY(6V 4Ah)
Description:
1) Power source: Rechargeable Battery 6V/4Ah or AC adaptor(9V,
500mA)
2) +5V power drives digital circuit system.
U11 (AIC 1722-5.0) is a 5volts Voltage Regulator.
3) +5V power drives analog circuit system.
U4 (AS2950A) is a 5 volts Voltage Regulator.
4) Auto-off:
If the indicator is set to 4_oFF of power-saving function or under
LO-BAT situation, after a fixed time interval (normally 4 minutes),
the CPU will release a low to high pulse signal to toggle U5, then
Q1 cuts off, indicator will be shut down immediately.
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