Changhong color TV CHD29618 power supply capacity reduction fault repair - android - Phones Developers

Probe domestic switch needle KG-300K needle head diameter is 3.0mm normally open switch needle

MOS power IC full range

1.5PF SOT23-6 Low Capacitance 5V Breakdown Voltage 6V SRV05

Photocoupler

A Changhong HD machine color chip 29618 check for insurance black, thick film block N801STR-W6756 damage, replace the new piece with 100w bulb voltage more than 80 volts, the second boot up to 135v, check the line no obvious short circuit, restore the circuit boot line The field is not full, check +B is about 100v, check the current 650mA, should be in the normal range, dial out the deflection and quickly start monitoring voltage is normal, so think that the package problem replaces the line package failure, change +B filter capacitor, precise and stable The pressure TL431 is still the same, it is a power problem or a part of the problem. Connect to the faulty machine from another newly repaired 29-inch TCL power supply cable. Check that the fault is turned on and the faulty machine is normal. The problem is still the power supply, the bulb is increased to 200w135v stable, check the market without results. Shut down, electric shock when flipping the bottom plate, found that the 300v capacitor discharge is slow, 300v after shutdown, it takes about five minutes to disappear, the power supply is really a problem? W6756 power supply is relatively simple, there are no abnormalities in the peripheral parts. The common load-carrying capacity of the power supply is mostly the R804 of the W6756's 11-pin connection [0.1Ω resistance value becomes large, check the resistance is normal, replace it with a few no effect. Because I can't find the voltage parameters of each foot of W6756, the maintenance can't continue.