Focus Adjustment; 2-4.1. Dynamic Focus/Dynamic Quadra-Pole Data - Sony TRINITRON KV-27HS420 Service Manual

2-4. FOCUS ADJUSTMENT

Confi rm neck assembly Z axis position. (See Figure 1)
1. Input a dot signal.
2. Set Video Mode to STANDARD.
3. Adjust focus VR clockwise (DE-Focus) to confi rm the dot's shape.
Center should be oval with left and right sides balanced.
4. Input a HD monoscope signal.
5. Confi rm center focus with focus VR.
KV-27/29/30 HS420
CRT: 29RSN/32RVE (NON-Super-Fine Pitch)
Neck Assy:NA2920 (VA-Type, Square pin assignment, VPIN harness)
G3
G2
Edge of G2 part
G1
Position tolerance: Just position +/- 0.5mm
KV-32/34/36 HS420
CRT: 34RSN/36RV2/38RSN (NON-super-fi ne pitch and round
fannel)
Neck Assy:NA328 (VA-type, square pin assignment, VPIN harness)
G3
G2
G1
Position tolerance: Just position +/- 0.5mm
G1 Cup Holder
Focus
Screen (G2)
KV-27HS420/29DRC420/30HS420/32HS420/34HS420/36HS420
Neck-Assy: NA2920
Center Step
Neck-Assy: NA328
Figure 1
MVD
KV-27HS420/29DRC420/30HS420/32HS420/34HS420/36HS420
DQP Dot Pattern
Center Dot Slightly Oval
NOTE: Changing neck assembly position will affect corner convergence.
2-4.1. DYNAMIC FOCUS/DYNAMIC QUADRA-
POLE DATA
Normally, no adjustments are necessary for these systems. If for some
reason the data is lost, use the data from Table 1 on Page 24:
Write the data from any non-vertically compressed mode, then use
the CPY1 function (CXA2170D-4 Item 6) to copy the data to the
vertical compressed modes. V-compressed data is identical to non-v-
compressed data. Service personnel with a trained eye can adjust the
DF or DQP registers to adjust DF phase (Item 7) or DQP phase (Item 8),
respectively, to balance left and right focus. Refrain from adjusting more
than 5 steps from table data below. Further adjustment indicates a circuit
problem -- troubleshoot to cause. Be sure that Neck Assembly is in the
proper location. Always mark position before moving or replacing neck
assembly.
(See Section 2-4 Figure 1 - before changing DF/DQP data or
troubleshooting circuit when DF/DQP is suspect.)
Procedure to adjust or check:
1. Input a cross hatch signal.
2. Short Q8018 B-E to disable DF – Markings are on the circuit board.
Circuit connection changes should always be done with the power off.
Caution: Q8018 heatsink is live and peak voltage is 250V.
3. Defocus or overfocus to adjust DQP phase. Adjust the data
(CXA2170-D4 item 8) to balance left and right vertical line width.
4. Once DQP is balance, remove the short from DF circuit and refocus
the set.
5. Adjust DF (CXA2170-D4 item 7) to balance left and right vertical line
width.
6. Reconfi rm focus performance.
Upper Corner
Center Horizontal Line
Lower Corner
16