LG TL-AT130M - Manual (Page 18)

3-8
SECTION3 ELECTRICAL
ELECTRICAL TROUBLESHOOTING GUIDE
(3) When the C(Color) signal doesn't appear on the screen in PB Mode
Check the circuit of the
IC301 Pin 35, 62.
NO
NO
Check the Color Rotary level.
(Check the R302, R303)
Is 5V applied to the IC301
Pin 16, 40, 55, 58, 87?
Is the Color Rotary signal applied to
the IC301 Pin 10?
YES
Is Color Rotary "H" about
1.6V?
YES
Check the Color Rotary
Circuit. (IC501 pin 98)
Replace the IC301.
Does the Color signal appear at
the IC301 Pin 71?
Replace the IC301.
YES
YES
NO
Does the Color signal appear
at the IC301 Pin 61?
Check the Color Pass.
(Check the Q304)
NO
NO Check the line of the 5.3VA
Line. (Power Circuit)
Replace the X301 or the X302.
NO
NO
Does the X301(4.43MHz) or
X302(3.58MHz) oscillate?
YES
(4) When the Video signal doesn't appear on the screen in REC Mode.
Check the circuit of the
IC301 Pin 90, 92, 94
NO
NO
Check PB Mode.
Is the EE signal normal?
Is 5V applied to the IC301
Pin 16, 40, 55, 58, 87?
YES
Does PB Mode operate
normally?
YES
Check the line of the 5.3VA
Line.(Power Circuit)
Check the Drum &
Drum Connector
Does the RF signal appear at
the IC301 Pin 12?
Does the REC RF signal appear at
the IC301 Pin90?
YES
YES
NO
Check REC Luminance
Pass & Color Pass.
Replace the IC301.
YES
NO
Check EE Mode.
Check the System of REC 'H'
(the IC501 Pin 30 / the D301)
NO
NO
Is the REC 'H' signal (about
4V)applied to the IC301 Pin 30?
YES
YES