Read Sharp 66FW-53H Service Manual online
DA100 (50Hz) Chassis – Article for Television Magazine
Page 66 of 80
NICAM or OPC
LED's illuminated
No
Reduced Vertical Scan
Increase
Screen control
Yes
Power supply is working correctly
Check data communication
(see LED's Fault code table)
re-program NVM if necessary
No Video
Check Video input selection
and IF stage
Correct
Waveform
Yes
Line Drive Fault
Check Q607 (crow bar)
and IC801
EHT Protection circuit operating
Check D617 and amplitude of the line fly-back pulse
Less Than1.8v
More Than 1.8v
Chart 2 - 140v rail Present
Before switching on ensure that the aerial is disconnected
Vertical Output Fault
1) Ensure IC501 pin 12 = 5v
2) Check IC501 +/- supply
3) Re-program NVM
2) Check IC501 +/- supply
3) Re-program NVM
Vertical Flyback fault
1) If R501 is over heating, reprogram NVM.
2) Check R530,Q502,Q503,Q507 and D507
Yes
Check
Line drive
IC801 pin 50
Check
OSD
Check
IC801 pin 12
Check
IC801 pin 11
(see waveform)
Incorrect
Waveform
No Vertical Scan
No
No
Check
IC1801 pin 2
12v
No LT supply to RGB output
Q912 and associated
components
Low
RGB output Fault
Check IC1801
Note:
If screen control is not
correctly adjusted then
stepping brightness will occur
Ok
Figure 63: Fault Finding Flow Chart 2
Sharp Electronics (UK) Limited - March 2003
Revision 2
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