Service manual

42
13VT-N100
13VT-N150
13VT-CN10
TROUBLESHOOTING OF VCR SECTION
Check/replace X7701 and/or IC2001.
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 IC2001? Is there oscillation (16MHz) at pins (38) and (39) of IC2001?
Are the PC 9V and PC 5V lines normal?
Check power circuit.
Check poor soldering.
Check power circuit.
Check the sensor inputs to IC2001 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 (8) of IC2001 when the key is activated?
Check IC2001.
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
NO
NO NO NO NO
NO NO
NO
NO
NO NO
Check pin (21) of IC2001 and all the way up to pin (5) of IC7701.
NO NO
CASSETTE CONTROL TROUBLESHOOTING FLOW CHART NO.1-3
A cassette tape is not taken in.
YES
YES YES YES YES YES
Fix or replace the cassette housing.
Check the start sensor cover.
Check the start sensor and the way up to pin (5) of IC2001.
NO NO NO
YES YES YES
Check IC7701 and AT12V line. Check between IC7701 and the loading motor.
A cassette tape is taken in, but ejected at once.
Replace IC2001
Is the cassette housing distored?
Does the start sensor cover become open when the cassette tape is inserted? Does the start sensor pin (5) of IC2001 go to "L" level when the cassette tape is inserted? Does pin (5) of IC7701 (BA6209) go to "H" level (about 1.8V) when the cassette tape is inserted? Check and replace the loading motor. Is the correct voltage at the loading motor terminal when the cassette tape is inserted? Does pin (2) of IC7701 go to about11V when the cassette tape is inserted?
Do the cam switches A and B operate normally when the cassette tape is loaded?
Does end sensor pulse at pin (6) of IC2001 change from "L" to "H" level when the cassette tape is loaded?
Does start sensor pulse at pin (5) of IC2001 change from "L" to "H" level when the cassette tape is loaded?
Check the start sensor and all the way up to IC2001.
Check the end sensor and all the way up to IC2001.
Check cam switches and all the way up to IC2001.