Power Supply Or Mainboard Fault
Dear Jestine,
I’m experience a problem i never see before. I have an aoc tv lcd 26inc which is dead but after a minute with supply On then the standby light comes on and after you press power the light go off and nothing happen. By looking at psu voltages without the connecter in mainboard just by shorting the ps On voltages remain ok 24v 12v and 5v seems psu is ok, the strange is that when I put the connecter in the mainboad the 5v become 4v so no standby light On. The 12v and 24V were good. After a minute what happens is that the stand by light comes On and 5 volts are back but then no 12volts and no 24v im very stuck thanks.
Humming Sound In DVD Player Power Supply
Hello sir,
I collected a dvd no power from a friend, and checked it i discovered that its fuse and bridge rectifier are blown also d capacitor swell up when i change all these components and i switched it on it blow another ic, the 3 by 4 ic so i changed it and changed the str w6053 ic too.
Then i use bulb test in other to avoid components being damaged again, so when i switched it on the bulb the not light on but the power pack is giving a huming like hissing noise i checked the output voltage but no voltage. Pls what can be the causes of the noise?, the noise is around the switch mode transformer. The dvd home theater is LG model no: HT357SD.
Thanks
TL431 Test
Dear Jestine,
Please I have a small problem and I need some advice.
I have a faulty TV with a faulty power supply. When I checked one of the output 3 legs IC1431T ,with coponent
analyser it gave the folowing result,
NPN DARLINGTON TRANSISTOR
COLL EMIT
DIODE PROTECTION BETWEEN C-E
RESISTOR SHUNT BETWEEN B-E HFE NOT ACCURATE DUE TO TO B-E RES
CURRENT GAIN .
HFC=1452
TEST CURRENT
IC=2.50Ma
BASE-EMITTER V
VBE=1.54V
TEST CURRENT
IB=3.78MA
LEAGAGE CURRENT
Ic=0.00mA
Burnt Components In Touch Sensor Lamp Circuit Board
Hi Jestine, a friend has brought me a touch activated lamp to see if I can fix it. Could i send you pics of the circuit board with blown components and see what you think could be wrong. Regards R.B