SONY DVD PLAYER SMPS - PWB SRV2020WW - Repair Help - SERVICE EXPERIENCE
The DVD player will start-up at first, No Display, and will shut down immediately. A "Tik-Tik-Tik" noise will be produced continuously from the SMPS board. No response to any key buttons on the panel or with the remote control.
Checked the DC voltage across the main filter capacitor. Found normal.Checked all the other components on SMPS board. All the SMD transistors used is OK. Checked all the diodes. OK. Checked the opto-coupler . OK.
On through checking, the D212 {Zener Diode} was found leaky.
This diode can be located near to the capacitor C511 [I've marked it here]
Switching STR used is > MIP2E4D. Opto-coupler > PC817.
Note the type of fuse [F101] used with this SMPS. It is rated at 1.25Amps 250VAC. We can use any type of fuse in place, provided it should be of the same rating. No other restrictions.
LEAKAGE CURRENT HOT TEST
> Plug
the AC cord directly into the AC outlet. Do not use an isolation transformer
for this check.
> Connect a 1.5kΩ, 10 watts resistor, in parallel with 0.15µF capacitors, between each exposed metallic part on the set and a good earth ground such as water pipe, as shown here.
> Use an AC voltmeter, with 1000 ohms/volt or more sensitivity, to measure the potential across the resistor.
> Check each exposed metallic part, and measure the voltage at each point.
> Reverse the AC plug in the AC outlet and repeat each of the above measurements.
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.
> Connect a 1.5kΩ, 10 watts resistor, in parallel with 0.15µF capacitors, between each exposed metallic part on the set and a good earth ground such as water pipe, as shown here.
> Use an AC voltmeter, with 1000 ohms/volt or more sensitivity, to measure the potential across the resistor.
> Check each exposed metallic part, and measure the voltage at each point.
> Reverse the AC plug in the AC outlet and repeat each of the above measurements.
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.
