Hitachi 51F710A/DP55 Service Manual page 41

Digital Convergence Repair Info. Check Adjustment Pattern
Confirm of appearance of DCU Crosshatch in DCU Adjustment Mode, by pushing of Service
Only SW (SCOI).
Procedure
1) Push Service Only SW (SC01) on SIGNAL PWB.
2) If DCU Crosshatch (corrected almost well) is displayed, Status is OK.
3) DCU Crosshatch is not displayed, Uneven Crosshatch or No Correction Crosshatch is
displayed, DCU circuit has any defects.
Counter Measure for Trouble
if DCU Crosshatch is not displayed (External Video Signal is continuously displayed),
check next items.
1) Assembly Error of DCU uCOM (IS07), X'tal (XS01), Reset 1C (IS05), or other peripheral
parts
2) Solder-Bridge of DCU uCOM (IS07) 7-13pin
3) Solder-Bridge of Reset 1C (IS05)
4) Solder-Bridge of PCJG connector
5) "Ys" signal line {from DCU LSI (IS06) 53pin to RGB processor (IX01) 2pin)
6) "Busy" signal line (from DCU uCOM (ISO?) 66pin to SUB uCOM (I001) 95pin)
7) "Reset" signal line (from Reset 1C (IS05) 4pin to DCU uCOM (IS07) 7pin)
8) +5V Power supply line (from PDT3 connector 10/11 pin to DCU uCOM (IS07))
If DCU Crosshatch is not displayed (External Video Signal is Muted), check next items.
1) Assembly Error of DCU LSI (IS06), +3.3V Regulator (IS04), or other peripheral parts
2) Solder-Bridge of DCU uCOM (IS07) 36, 72-73pin
3) Solder-Bridge of DCU LSI (IS06) 5, 7,14, 22-25, 29-31, 33-35, 38-39, 48-50pin
4) "Ys" signal line (from DCU LSI (IS06) 53pin to RGB processor (IX01) 2pin)
5) "DCU OSD" signal line (from DCU LSI (ISOG) 48/49/50pin to RGB processor (IX01)
24/25/26pin
6) "Busy" signal line (from DCU uCOM (IS07) 66pin to SUB uCOM (I001) 95pin)
7) "H.BLK/V.BLK" signal line (from PDT2 connector 7/11 pin to DCU LSI (IS06) 33/35pin
8) PLL of DCU LSI (RS65/67, CS32)
9) +5V Power supply line (from PDT3 connector 10/11 pin to DCU LSI (IS06))
10) +3.3V Power supply line (from +3.3V Regulator (IS04) 4pin to DCU LSI (IS06))
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DP55