December, 2002
Hitachi America, Ltd., Home Electronics Division
PTV
National Service
Page 1 of 2
MODEL: All DP-2X Models
SUBJECT: Convergence Troubleshooting Procedure
Please use this troubleshooting flowchart* to diagnose convergence problems.
Convergence can not be corrected
W hat color has shifted? ALL A
RED GREEN BLUE
Check DCU output waveforms
KK55 / PDS(19) RV* KK53 / PDS(16) GV* KK51 / PDS(13) BV*
KK56 / PDS(20) RH** KK54 / PDS(17) GH** KK52 / PDS(14) BH**
GOOD BAD GOOD BAD GOOD BAD
W hat has shifted? W hat has shifted? W hat has shifted?
Horizontal or Horizontal or Horizontal or
Vertical? Vertical? Vertical?
Horiz Vert Horiz Vert Horiz Vert
Check Check Check Check Check Check
Replace
RV RH GV GH BV BH
DCU
Output Output Output Output Output Output
Check Check Check Check Check Check
and/or and/or and/or and/or and/or and/or
replace replace replace replace replace replace
IK04 IK04 IK04 IK05 IK05 IK05
RK46 RK42 RK62 RK58 RK54 RK50
* = RV, G V, BV ** = RH, GH, BH
0.0 Vdc 2~5 Vpp 0.0 Vdc 2~5 Vpp
16~17 ms 16~17 ms
Note: KK(xx) & K(xxx) = Jumper (xx or xxx)
PDS(xx) = DCU connector (pin xx)
RK(xx) = Resistor (xx)
LK(xx) = Coil (xx)
*Although this specific flowchart is tailored to the DP-2x chassis, it generally applies equally to
any PTV using a DCU (Digital Convergence Unit); the actual components may vary.
1. Check DCU output waveforms to determine if the DCU is working.
2. Check DCU DC voltages.
3. Check DCU input blanking signals ( H and V). (continued)
PTV 02-02 Page 2 of 2
A
Check DCU
DC voltages
Check IK01, SW +7V
BAD
Is voltage at jumpers
{Check QK01, SW -7V}
K273 {K274}
+5V {-5V}?
GOOD
Check DCU
Blanking inputs
BAD
Check DEFLECTION CKT
coil LK07*** (H BLK)
coil LK08**** (V BLK)
GOOD
DP24 ONLY
Check +33V {-33V)
BAD
Is voltage at IK04,IK05 Check fuse FK01 {FK02}
pin 5, {pin 4}
+30 ~ +33V {-30 ~ -33V}
Check:
GOOD
resistors RK42, RK46,
RK50, RK54, RK58, RK62
Output STKs IK04, IK05
DCU
*** = H BLK **** = V BLK
4 ~ 5 4 ~ 5
Vpp Vpp
2.5 ~ 3.5 µ s 16~17 ms