1 Safety Precautions
1.1. GENERAL GUIDELINES
1. When servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overheated or
damaged by the short circuit.
2. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers shields are properly
installed.
3. After servicing, carry out the following leakage current checks to prevent the customer from being exposed to shock hazards.
1.1.1.
LEAKAGE CURRENT COLD CHECK
1. Unplug the AC cord and connect a jumper between the two prongs on the plug.
2. Measure the resistance value, with an ohmmeter, between the jumpered AC plug and each exposed metallic cabinet part on
the equipment such as screwheads, connectors, control shafts, etc. When the exposed metallic part has a return path to the
chassis, the reading should be between 1M
Ω
and 5.2M
Ω
.
When the exposed metal does not have a return path to the chassis, the reading must be
1.1.2.
LEAKAGE CURRENT HOT CHECK
1. Plug the AC cord directly into the AC outlet. Do not use an isolation transformer for this check.
2. Connect a 1.5k
Ω
, 10 watts resistor, in parallel with a 0.15µF capacitors, between each exposed metallic part on the set and a
good earth ground such as a water pipe, as shown in
Figure 1
.
3. Use an AC voltmeter, with 1000 ohms/volt or more sensitivity, to measure the potential across the resistor.
4. Check each exposed metallic part, and measure the voltage at each point.
5. Reverse the AC plug in the AC outlet and repeat each of the above measurements.
6. The potential at any point should not exceed 0.75 volts RMS. A 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.
Figure 1
1.2. Before Repair and Adjustment (Using SMPS Module P.C.B.)
This unit uses Switching Mode Power Supply (SMPS) Module P.C.B. to provide the neccessary voltages for the unit.
Caution:
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 110-240 V, 50/60 Hz in NO SIGNAL mode volume minimal should be ~ 650 mA.
Note:
It is advisable to replace the SMPS Module P.C.B. as a unit.
1.3. 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.
5
SA-PT150GC / SA-PT150GCP / SA-PT150GCS / SA-PT150GCT / SA-PT150GS
Содержание SA-PT150GC
Страница 12: ...12 SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS ...
Страница 19: ...7 5 4 Connection for Set Top Box 19 SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS ...
Страница 37: ...9 2 Main Components and P C B Locations 37 SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS ...
Страница 64: ...SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS 64 ...
Страница 72: ...72 SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS ...
Страница 84: ...SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS 84 ...
Страница 93: ...24 Exploded Views 93 SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS ...
Страница 94: ...94 SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS ...
Страница 95: ...24 1 Cabinet Parts Location SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS 95 ...
Страница 96: ...SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS 96 ...
Страница 97: ...24 2 Packaging SA PT150GC SA PT150GCP SA PT150GCS SA PT150GCT SA PT150GS 97 ...
