General Information; Cautions On Servicing Amp Assy (Axw7007, Axw7008) - Pioneer S-W1EX Service Manual

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7. GENERAL INFORMATION

7.1 CAUTIONS ON SERVICING AMP ASSY (AXW7007, AXW7008)

A
1 Both of outputs of Amp (CN481) are + poles. (DC23.5V)
Float the grounding terminal of the power cord of the measuring instrument of measurement equipment
GND of a measuring instrument does not connect with a chassis.
Especially while observing between SP+ and SP- with the oscilloscope (either is connected to GND of a probe),
GND of the probe of another channel also floats.
Other products are not connected.
B
It happen : FET Q421, Q431, Q441, Q451 (IRFB23N15D) of AMP breaks in the short mode.
IC421 and IC441 (IR2011S) break.
2 Since HIGH VOLTAGE AREA of SMPS Assy has high voltage, you need to take care.
Fundamentally, don't touch during turning on electricity.
Voltage MAX 650VDC
3 After turning on electricity, work after short-circuiting and discharging DISCHARGE POINT of SMPS Assy
by 3W 100ohm resistance, when checking a ASSY. (Refer to "Caution Point" sheet)
C
Discharge D2:A-K
points D3:A-K
CN31:1-2
4 Don't observe primary side and secondary side with the same oscilloscope simultaneously.
It happen : It causes insulated destruction and a product and a measuring instrument break.
Moreover, when the worst, the electricity of a building falls.
D
5 Since it gets hot rapidly, while taking out power, don't touch TH1.2 of SMPS Assy. (Refer to "Caution point" sheet)
6 Since FET has broken when a speaker relay does not turn on in a thing without a cable un-connecting, check.
(Refer to Repair flow)
7 In the following cases, turn VR321 and adjust DC offset between the pins 1-2 of CN481 to less than [ +-20mV ].
Perform a measuring instrument in the TR6847 multi-meter of ADVANTEST, or its considerable article.
Load is taken as the speaker of a set, 4-ohm dummy resistance, or opening.
Input signal is nothing.
E
MainVOL is min.w)
When FET (Q421,431,441,451) and IC421,441 are exchanged
When D AMP ASSY AWU8170 is exchanged
* Since a driver becomes middle point potential (DC23.5V) when using a metaled driver,
Does not short-circuit with a chassis or you don't receive an electric shock.
As long as it takes care, a metal driver may adjust.
F
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