leakage current tester (Simpson Model 229 or equivalent) may be
used to make the hot checks, leakage current must not exceed 1/2
milliamp. In case a measurement is outside of the limits specified,
there is a possibility of a shock hazard, and the equipment should
be repaired and rechecked before it is returned to the customer.
2. Handling the Lead-free Solder
2.1. About lead free solder (PbF)
Distinction of PbF P.C.B. :
P.C.B.s (manufactured) using lead free solder will have a PbF stamp on the P.C.B.
Caution:
- Pb free solder has a higher melting point that standard solder;
Typically the melting point is 50 - 70°F (30 - 40°C) higher. / Please
use a high temperature soldering iron. In case of the soldering
iron with temperature control, please set it to 700 ± 20°F (370 ±
10°C).
- Pb free solder will tend to splash when heated too high (about
1100°F/600°C).
- When soldering or unsoldering, please completely remove all of
the solder on the pins or solder area, and be sure to heat the
soldering points with the Pb free solder until it melts enough.
3. Before Use
Be sure to disconnect the mains cord before adjusting the voltage selector. Use a minus (-)
screwdriver to set the voltage selector (on the rear panel) to the voltage setting for the area in
which the unit will be used.
(If the power supply in your area is 117V or 120V, set to the “127V” position.)
Note that this unit will be seriously damaged if this setting is not made correctly. (There is no
voltage selector for some countries; the correct voltage is already set.)
4. Before Repair and Adjustment
Disconnect AC power, discharge Power Supply Capacitors C546, C547, C548, C549 through a
10 , 1 W resistor to ground.
DO NOT SHORT-CIRCUIT DIRECTLY (with a screwdriver blade, for instance), as this may
destroy solid state devices.
After repairs are completed, restore power gradually using a variac, to avoid overcurrent.
Current consumption at AC 220~230V, 50Hz in NO SIGNAL mode should be ~400 mA.
5. Protection Circuitry
The protection circuitry may have operated if either of the following conditions are noticed:
- No sound is heard when the power is turned on.
- Sound stops during a performance.
4
To Next Page
Loading...
