26
Test
21. TESTING THE DC PROTECTION CIRCUIT :
1
Preliminary test:
Verify that the amplifier is turned off (switch at rear panel)
Turn the RV1 bias adjust trimmer fully counter clockwise
(turn left)
For first time testing, insert a 60W light bulb in series
with the AC power line.
Connect the power cord
(it is possible that the supplied cord or
connector must be replaced to comply with the requirements of your country)
Turn ON the amplifier using the switch at the rear panel
If the light bulb lights up continuously, disconnect the mains volt-
age and check all your wiring and assembly.
The power LED LD4 should lit.
If the 60W lamp remains off or lights up briefly, then everything is OK,
Remove the light bulb from the circuit.
Recheck carefully if the selection of primary AC voltage, complies to your
mains voltage.
120Vac
: black / brown.
230Vac
: black /orange.
IMPORTANT
: Insulate the wire that is not being
used.
2
Setting the bias:
Connect a multimeter (lowest DC voltage range 1V or
lower) over the leads of R42 or R43.
Turn on the power.
Check the multimeter, it should read 0V, adjust RV1
carefully to about 10-15mV (0.010V-0.015V) Wait a
few minutes until the meter reading remains stable.
Note: the amplifier will turn itself off after about 15 minutes.
Remove the multimeter
Summary of Contents for POWER BLOCK K8081
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Page 12: ...12 Assembly 5 bend C4 away from T9 bend C5 away from T8...
Page 33: ...33 PCB 23 PCB...
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