VSX-D914-K
77
5
6
7
8
5
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7
8
C
D
F
A
B
E
7.3.5 AMPLIFIER FAILURE DIAGNOSIS FLOW CHART
7.4 CLEANING
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.
As DC detection and fan stop protection circuits commonly use same abnormality detection port in
microprocessor, please make sure that the operation of fan motor is in normal condition before proceeding to
the troubleshooting of amplifier.
Caution:
When release the lock state of power key before repair, please be careful because there is the possibility that
more damages will occur when turns on the power once again!
• According to a symptom, perform the following confirmation beforehand.
1) Is the operation of fan motor in normal condition?
2) Are there any Fuses and IC protectors open?
3) After turn on the power, confirm that the supply voltage of the point that can be measured is appropriate.
4) Whether the voltage of pin3 of IC601 or IC602 is equal to (VL-0.7V). If not (eg, equal to VH), then change
the corresponding power pack IC601 or IC602.
5) Furthermore, check the output DC voltage of each channel of power pack IC601 and IC602 to limit the
failure channel and identify the defect power pack.
• After identify the failure channel, check that each part is not damaged (resistor, diode... etc. value / open /
short)
Before shipping out the product, be sure to clean the following positions by using the prescribed cleaning tools:
Position to be cleaned
Cleaning tools
Fans
Cleaning paper : GED-008
