sunny 12at057 v1.3 led tv not working
good work sunny 82 screen when the TV came on ppd1 diode was burned and Q3 thyristor was burned I changed the tv shoo sound image 48 led voltage is not 75 volts increase pic1 integrator has 17 volts in 1 pic Q3 no thyristor driven I have led driver circuit in cold solder and changed the capacitor in the capacitor the same fault: note: I try the TV with another card LEDs are on
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Hi to all forum members,
Got this faulty 350 watt atx psu dirt cheap from a local online seller as i am keen to use it as a learning tool to repair faulty power supply.
The faulty part is quite obvious from the burn area near the 16pin KA7500 BD pwm. The fuse is still intact with good continuity.
Upon power on ac, there is 5vdc standby power on cathode of diode D14 and about 10vdc on cathode of diode D13.(This should be the aux power to generate the 12v and 5v rail.)
Initially i replace the two burned resistors near my marked red arrow to 200 ohm resistor... -
Hi everyone,
Brought a non functionnal PS5. Apparently only a bad PSU...
No beep, nothing.
After some tests i found this :
- PSU is fine (12 volts stable)
- 12 volts line is shorted
- DA9065 was fried, F7003 also => Replaced both of them, short is gone on 12 volts line, no dead short anywhere else.
- By the way, nothing change. No signal, no power, no beep.
Mesuring all rails with my workbench psu (12 volts input)
- 0.00 amp drawing
- 12 volts, 5 volts, 2 volts, 1,15 volts are presents (suppose new DA9065 do is... -
Good day to all. The bite alarm drains 9-volt Krona batteries. Current consumption when switched on is about 50 mA. I wiped the board from oxides, I will attach a photo (on the board there is a j3y transistor and a 7533 stabilizer, the microcircuit is erased = (the 3.3-volt stabilizer heats up weakly. I replaced it, nothing changed. I unsoldered the microcircuit, the consumption disappeared. The resistance on the pins of the unsoldered microcircuit from the point clockwise is more than 2 megaohms, the 11th leg is presumably ground. I warmed up the microcircuit, the consumption does not change....
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Hello,
Dell Latitude 5420 P137G
Board: LA-K491P REV A01
I have received this laptop which was described as "does not power on or accept charge." Battery shows no sign of charging when charger is plugged in, nor does the board show any signs of life when battery is unplugged and charger is plugged in. No light from the LED at all or any other indications of activity.
Board seems to have no shorts, all power rails are fine and show high resistance.
When charger is plugged in, voltage is present in 3.3V rail but absent in others.... -
Hi, I would like to share my experience...
So, I came across with common problem - no 50V on PSU 40-PF0750-PWD1G
L6566B was burned. Between pin 7 and GND were short circuit. I replaced L6566B with a new one, but it gave me nothing. However, it started if I touched pin 16 with multimeter probe. Obviously the protection is triggered.
If we look at the L6566B datasheet, we will see that to deactivate the protection (AC_OK), is enough to exceed 0.450 volts.
In my case, I have had 0.632 volts. This is enough at the first glance. But on the oscillogram on pin 16, I observed noise...
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