Diagnosis method for 3 times flashing PD
Diagnose 3 times flashing PD according to the steps below
1. Visual check with Power off condition
2. Impedance check with power off condition
3. Voltage check with power on condition
Actual diagnosis methods are as follows
1. Visual check with Power off condition
Check the all of connectors and FFC on Y Drive Assy whether completely connected
2. Impedance check with power off condition
i ) Impedance check between Vsus - SUSGND on Power Supply Assy
If the impedance is several hundreds k ohm or over -> go to step " ii "
If the impedance is short circuit -> Remove P1 and P2 connectors and check impedance
between Vsus - SU
S
GND on X Drive and Y Drive Assy.
Follow check steps below.
Vsus - SUSGND impedance check on X and Y Drive Assy with no Vsus cables
If the impedance on X Drive Assy is short circuit → Replace X Drive Assy
Vsus-SUSOUT or SUSOUT-SUSGND are short circuit : Defective of X MASK module IC
Other than above : defective of other devices
If the impedance on Y Drive Assy is short circuit → Replace Y Drive Assy
Vsus-SUSOUT or SUSOUT-SUSGND are short circuit : Defective of Y MASK module IC
Other than above : defective of other devices
If the impedance on Power Supply Assy is short circuit → Replace Power Supply Assy
NOTE: Because some capacitors have voltage, it seems impedance is short just after
measuring of impedance by multimeter.
Actually if no short circuit , the impedance is soon going up.
ii ) Impedance check between VH - PSUS on Y DRIVE Assy
If the impedance is several M ohm or over -> go to step 3
If the impedance is short circuit -> Remove bridge connectors between Y Drive Assy and Scan A or
B Assy and check it again at Y drive, Scan A and Scan B Assy.
Short circuit on Scan A Assy ->
Scan IC on Scan A Assy is defective
Short circuit on Scan B Assy ->
Scan IC on Scan B Assy is defective
Short circuit on Y Drive Assy ->
Defective of Y Drive Assy
3. Voltage check with power on condition before PD is working
Vsus voltage is not going up to around 200 V -> Defective of Power Supply Assy
VH voltage is not going up to around 130 V ->
Defective of DC-DC converter on Y Drive Assy
4. Check of Power Down detection circuit
If there is no problem step 1, 2, and 3, both of VH voltage and VSUS voltage are normal, but PD
circuit is working. Therefore PD detection circuit has problem.
-> Replace Y Drive Assy : because detection circuits for 3 times PD are on Y Drive Assy
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