Scan Ic Check; Mis-Discharge Defect; Scan Ic Output Diode Check; Mis-Discharge - Philips PDP42V7 series Service Manual

EN 14 5. LGE PDP
Disconnected
Screen off
Figure 5-22 Check drive connectors

Scan IC Check

Check diode value of the right side part of the output pin.
Normal diode value= 0.6 (forward)
Figure 5-23 Scan IC output diode check
5.1.5 Line Defect (Horizontal)
FPC Check
In case of one or more horizontal lines, this is probably due to
FPC or panel inside the Control board. Y board is just normal.
FPC electrode open
Figure 5-24 Open FPC electrode / Panel electrode breakdown
Service Modes, Error Codes, and Fault Finding
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Normal diode value= OL (reverse)
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Panel electrode
Insulation break down
Horizontal 1 line.
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Scan IC Check
Check diode value of the right side part of the output pin.
Figure 5-25 Scan IC output diode check
5.1.6

Mis-discharge Defect

Most of mis-discharge appearance is a problem of Y-DR, Y-
SUS, or Z board.
Check these boards when mis-discharge occurs.
Figure 5-26 Mis-discharge
Checking Order
1. Check Y- and Z-SUS signal cable.
2. Check if Y-DRV IC is defective.
3. Check Y-SUS board voltages (-Vy, Vscw)
4. Check if Y- and/or Z-SUS IPM are defective (see
paragraph "How to Check IPM" below).
5. Replace Control board
How to Check IPM
Forward direction
Measure between:
• GND (+) and Sus-out (-).
• Sus-out (+) and Vs (-).
When each two test diode values is over 0.4V => OK.
Reverse direction
Measure between:
• GND (-) and Sus-out (+).
• Sus-out (-) and Vs (+).
When each 4 nodes test diode values is infinite => OK
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