Samsung UA43J5100…
The problem is totally dead, the indicator light does not work.
Remove the connector from the PSU to the motherboard….
Plug in the electricity… .. the BL light can light up….
This indicates that the PSU is normal ……
Check the voltage out to the motherboard ..... only use a single 13v
Check the 3.3v standby voltage….
The easiest ……… looking for the test point on the IR remote sensor receiver… ..
It turns out ……… zero….
Check with an ohm meter …… does not show “short” ……
Suspicion …… clogged voltage from the 13v voltage which is lowered to 3.3v for standby …… ……….
Generally using IC Dc-Dc Step Down ……….
The characteristics of the dc-dc sterp down ……… .. are nearby using the “COIL” …… which is also the output of the step-down dc's….
Use an ohmmeter …… .. look for a dc-dc ic whose output is connected to a 3.3v IR receiver… ..
found it …….
Namely ic OZ3015 …… ..
Look for the ic data sheet .... to find out the "INPUT" pin that connects to 13v….
Input meets pin-2 ...
Check ……. Turns out there is no 13v ……
…
After the .... lines pcb motherboard …….
Found .... there is a "fuse" that broke on the line from the 13v connector to pin-2 ... ..
This is the first time I've met Samsung motherboards using fuse ........ the most commonly used is the SONY motheboard.
After the fuse is connected ……… the indicator light can come on ……
On-power-on …… .OK …… the sound is there….
But how come the image is blank ????
Check Tcon …… Tcon's fuse also broke….
Check the Tcon input line with an ohm meter….
…… .short with ground …… this is what causes the fuse to break .......
Tinkering here and there ... it turns out that there is a short SMD capacitor on the 12v input line ...
After replacing the smd capacitor …….
……… pictures can be present… ..
Conclusion… .fuse on the mother board may also break due to a short 12v Tcon line….
Display: 42.5 in, VA, Edge LED, 1920 x 1080 pixels
Dynamic contrast: 1000000 : 1
Refresh rate: 50 Hz / 60 Hz
Frame interpolation: 100 CMR (Clear Motion Rate)
TV tuner: Analog (NTSC/PAL/SECAM)
SoC: Hawk-MF
Cores: 4
Dimensions: 962.9 x 561.3 x 66.9 mm
Weight: 7.7 kg