Service manual

13VT-K100/150
13VT-CK10
42
TROUBLESHOOTING OF VCR SECTION
Check/replace X7701 and/or IC7701.
ELECTRICAL TROUBLESHOOTING
VCR POWER TROUBLESHOOTING
FLOW CHART NO.1-1
The VCR is dead.(No power)
Unplug the AC power cord. Replug it a few minutes later.
Are the AT 5V and AT 12V lines normal?
Are the AT 5V and GND lines properly connected with IC7701? Is there oscillation (16MHz) at pins (38) and (39) of IC7701? Does the "L" pulse of sys- con reset appear at pin (43) of IC7701 after the AC cord is plugged in?
Does pin (21) of IC7701 change from "L" to "H" level when the power button is pressed to turn on the power? Are the PC 9V and PC 5V lines normal?
Check power circuit.
Check poor soldering.
Check the signal line of sys-con reset all the way up to pin (42) of IC3101. Check the power key input to IC2001 and serial datas/clocks between IC2001 and IC7701.
Check power circuit.
Check the sensor inputs to IC7701 from mechanism. (CAM switches,start/end sensors,and reel sensors)
KEY-IN TROUBLESHOOTING
FLOW CHART NO.1-2
Key-in input for VCR is not received.
Is the key switch in good contact?
Is there short-circuit in the key input?
Are signals received at pin (27) of IC2001 when the key is activated?
Check IC7701, IC2001 and signal line of serial datas, serial clock and ready (L).
Check the switch contact.
Check IC2001 and switches for poor soldering.
Check key lines to input IC2001.
YES
YES YES YES YES YES YES YES
YES YES
NO
NO NO NO NO NO NO
NO NO