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7.3.3 AMPLIFIER FAILURE DIAGNOSIS FLOW CHART
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Amplifier failure diagnosis flow chart
When DC detection is activated ("AMP_ERR" flashes on the display), failure (damage) of the power amplifier
section is considered.
Caution:
When releasing the lock state of power key before repair, please be careful because there is the
possibility that more damages will occur when turning on the power once again!
• According to a symptom, perform the following confirmation beforehand.
1) Are there any Fuses and IC protectors open?
↓
2) After turn on the power, confirm that the supply voltage of the point that can be measured is appropriate.
(Particularly the supply voltage of the power Tr and drive step)
↓
3) Whether the voltage of pin2 and pin5 of IC601, IC602 or IC603 is equal to (VL-0.7V). If not (eg, equal to VH),
then change the corresponding power pack IC601, IC602 or IC603.
↓
4) Furthermore, check the output DC voltage of each channel of power pack IC601, IC602 and IC603
to limit the failure channel and identify the defect power pack.
TE
L 13942296513
↓
• After identify the failure channel, check that each part is not damaged (resistor, diode... etc. value / open /
short)
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