Flowchart chart of alignment procedure for M28 chassis:
B+ adjustment
NICAM
Adjustment
Electrical
properties
checking for
chassis
RF
AGC
adjustment
Sub-brightness
Adjustment
White
balance
Adjustment
Aging Adjustment
of
screen voltage
and focus
Sub-color
&
Sub-tint
adjustment
Pincushion and
screen width
adjustment
Screen
center
& size
adjustment
(PAL)
Screen center
& size
adjustment
(NTSC)
QC checking
ALIGNMENT PROCEDURE FOR M28 CHASSIS:
I) Adjustment of B+ voltage
1. Apply 110-240VAC(
±
5V) to mains power input, and Philips standard testing pattern to RF input.
2. Adjust VR830 in STANDARD mode until voltage at TP2 (B+) is 112V
±
0.5V.
II) NICAM Adjustment (for NICAM model only)
1. Apply a 38.9MHz color bar with NICAM signal to the IF input.
2. Monitor the DC voltage at pin 15 of IC1101.
3. Adjust T1101 until the voltage at pin 15 of IC1101 becomes 2.5 +/- 0.1V.
4. Then check the waveform at pin 4 and 6 of P1103 and it must show correct audio signal.
III) The alignment of RFAGC
1. Connect the detector shown below to collector of Q101.
2. Receive a grey scale signal with 70dB
μ
V amplitude.
3. Adjust RFAGC item until the output of the detector becomes 0.8Vpp
Collector
of Q101
To CRO
