Samsung Odyssey G9 (c49g95tssr) no picture or backlight. Power LED shows

[grimreaper420]

Does this transistor have all legs 1, 2, 3 shorted?

I'll check now

[grimreaper420]

Does this transistor have all legs 1, 2, 3 shorted?

yes! i checked the 2 circle highlight in diode mode in multimeter and it beeps and shows 0.000 on all 4 no matter which way i test in whichever combination

[lotas]

I'll check now

You circle the entire transistor, and not one of the terminals, so you think what comes to all the terminals.

[lotas]

yes! i checked the 2 circle highlight in diode mode in multimeter and it beeps and shows 0.000 on all 4 no matter which way i test in whichever combination

Don't you see that I circled 2 under the number (this is one conclusion, they are connected together by paths), and 1 and 3 are different conclusions!

[grimreaper420]

Don't you see that I circled 2 under the number (this is one conclusion, they are connected together by paths), and 1 and 3 are different conclusions!

ah i see. black probe on 3 and red probe on 2 returns 0.476v (in diode mode), otherwise everything else returns OL

[lotas]

It's working, but it's hard to check remotely with you, I'm already tired, check these points again, between 1 and 2, between 1 and 3 and between 2 and 3, what's the resistance.

And also with 4 (1-4, 3-4).

[grimreaper420]

It's working, but it's hard to check remotely with you, I'm already tired, check these points again, between 1 and 2, between 1 and 3 and between 2 and 3, what's the resistance.

And also with 4 (1-4, 3-4).

in diode mode it all comes out at OL, apart from 3-4 it is 0.417v

in Ohms it just from 12 all the way down to OL back up to 12 and keeps doing it.

its been a long few days. we can take a break for a few days and come back to it

[harp]

Yes and before break, please fill next table, so we can thinking awhile... about mistery DFN component...

Set multimeter in diode mode, and firmly put red (yes RED) probe to ground (marked arrow GND on image)

Then with black probe firmly touch solder blob arround chip, marked with number and write down measurement reading. Do few times, reading must be the same.

1 - ?
2 - ?
3 - ?
4 -
5 -
6 -
7 -
8 -
9 -
10 -

And also for fuse and mosfet

X -
Z -
W -
Y -

[grimreaper420]

Yes and before break, please fill next table, so we can thinking awhile... about mistery DFN component...

Set multimeter in diode mode, and firmly put red (yes RED) probe to ground (marked arrow GND on image)

Then with black probe firmly touch solder blob around chip, marked with number and write down measurement reading. Do few times, reading must be the same.

1 - ?
2 - ?
3 - ?
4 -
5 -
6 -
7 -
8 -
9 -
10 -

And also for fuse and mosfet

X -
Z -
W -
Y -

Here are my results (red probe on GND on the image)

1 - 0.402
2 - 0.530 / 0.533 / 0.531
3 - OL
4 - 0.559
5 - OL
6 - 0.001
7 - 0.009 / 0.011 / 0.012
8 - 0.560 / 0.559 / 0.561
9 - 0.517 / 0.515

X - OL
Z - 0.020

Thank you for the help Harp & lotas

[harp]

10 -
W -
Y -

So, I guess that on point P in picture is ground, confirm?


Before future, can you tell us what you can do and what tools you have, I ask because I am not so confident regardless to your data input, but see strong will

Experianced in desoldering smd -
Experianced in ripps pads -
Know basic process of microsoldering -
Lab PSU -no
Some 5v adapter for phone with round connector (what mA?) -
Any chinese module for control voltage, current -
Thermal camera -no
NTC sensor (from laptop battery) -
Thermocoupling wires for DMM -
Solder iron (controll temperature,?? Watt, what tips) -
Soldering tin -
Soldering wick -
Soldering flux -
IPA -
Hot air -
Fine tweezers -
DMM -yes
Handheld magnify glass about 10x, or maybe on phone -
Anything else -

[grimreaper420]

10 -
W -
Y -

So, I guess that on point P in picture is ground, confirm?


Before future, can you tell us what you can do and what tools you have, I ask because I am not so confident regardless to your data input, but see strong will

Experianced in desoldering smd -
Experianced in ripps pads -
Know basic process of microsoldering -
Lab PSU -no
Some 5v adapter for phone with round connector (what mA?) -
Any chinese module for control voltage, current -
Thermal camera -no
NTC sensor (from laptop battery) -
Thermocoupling wires for DMM -
Solder iron (controll temperature,?? Watt, what tips) -
Soldering tin -
Soldering wick -
Soldering flux -
IPA -
Hot air -
Fine tweezers -
DMM -yes
Handheld magnify glass about 10x, or maybe on phone -
Anything else -

for point P i connected red probe to ground part and black probe to point P in diode mode returned 0.000 / 0.0001

10 - 0.514
y - 0.469
w - 0.469

im not experienced with electricals (but i am learning). I only have DMM. I can buy any extra equipment needed though

[harp]

Oh, so... you realise that only with dmm you can not do much... I explain to you on ic 5228E example


1 - 0.402
2 - 0.530 / 0.533 / 0.531
3 - OL
4 - 0.559
5 - OL
6 - 0.001
7 - 0.009 / 0.011 / 0.012
8 - 0.560 / 0.559 / 0.561
9 - 0.517 / 0.515
10 - 0.514

About that ic we known almost nothing... the measurement on all pins you want to see like 'identifier', so you see that pin 4 and 8, and pin 9 and 10 may be connected together or have same properties eg inputs. Pin 3 is probably provide power, based on thicker track and near smoothing capacitor.

Also, you see there is very suspicious reading on pin 7, and pin 5.
Pin 7 connect capacitor parallel with ic, and for some reason it is suspicious low reading. Next step would be to desolder that cap (with iron, you dont want stres ic for that trivial job), measure it off-circuit, and repeat measurement of pin 7 without it, while we hope that low redings are not come from ic or that it consider normal... That involve tools and practice (experiance), first you can buy, second dont.
Pin 5 must read more likely like pin 7, if your resistor is ok (10 ohm) and you previous confirm that it have 10 ohm accross it. So, the provided data is not match, and you must see why. That observation and that conclusion you have first noticed while measuring, so bring attention.

With dmm you can do in-circuit measurement, basicaly resistance and voltage. While resistance is done wth disconnected monitor from mains, the only risc is mechanical damage with probe tip, or wrong measurements. If you measure voltage, the risc is very very high, because your probe may slipped a little bit and short somethin, and it is game over, you cant buy replacement 5228 ic for example. So that you lower the risc, you must practice, know that you do not measure directly on legs of that small chip but on exposed near components, or gently scraped on wide part of track...

If you take my sugestion, that is nice expensive monitor, and you must first know and impruve your abilityes to work with needed tools, so, put it aside a bit, and practice some time on cheap stuff like power supply, old laptop and so on...

When you do couple smps repair, maybe you have to ask yourself, is that your monitor adapters is ok, have it provide declared power under load, because it is first common on both monitor...

[grimreaper420]

Oh, so... you realise that only with dmm you can not do much... I explain to you on ic 5228E example


1 - 0.402
2 - 0.530 / 0.533 / 0.531
3 - OL
4 - 0.559
5 - OL
6 - 0.001
7 - 0.009 / 0.011 / 0.012
8 - 0.560 / 0.559 / 0.561
9 - 0.517 / 0.515
10 - 0.514

About that ic we known almost nothing... the measurement on all pins you want to see like 'identifier', so you see that pin 4 and 8, and pin 9 and 10 may be connected together or have same properties eg inputs. Pin 3 is probably provide power, based on thicker track and near smoothing capacitor.

Also, you see there is very suspicious reading on pin 7, and pin 5.
Pin 7 connect capacitor parallel with ic, and for some reason it is suspicious low reading. Next step would be to desolder that cap (with iron, you dont want stres ic for that trivial job), measure it off-circuit, and repeat measurement of pin 7 without it, while we hope that low redings are not come from ic or that it consider normal... That involve tools and practice (experiance), first you can buy, second dont.
Pin 5 must read more likely like pin 7, if your resistor is ok (10 ohm) and you previous confirm that it have 10 ohm accross it. So, the provided data is not match, and you must see why. That observation and that conclusion you have first noticed while measuring, so bring attention.

With dmm you can do in-circuit measurement, basicaly resistance and voltage. While resistance is done wth disconnected monitor from mains, the only risc is mechanical damage with probe tip, or wrong measurements. If you measure voltage, the risc is very very high, because your probe may slipped a little bit and short somethin, and it is game over, you cant buy replacement 5228 ic for example. So that you lower the risc, you must practice, know that you do not measure directly on legs of that small chip but on exposed near components, or gently scraped on wide part of track...

If you take my sugestion, that is nice expensive monitor, and you must first know and impruve your abilityes to work with needed tools, so, put it aside a bit, and practice some time on cheap stuff like power supply, old laptop and so on...

When you do couple smps repair, maybe you have to ask yourself, is that your monitor adapters is ok, have it provide declared power under load, because it is first common on both monitor...

Ah okay. I will practice on some other small repairs and soldering first.

I bought a Lab power supply and thermal camera today. So that might help with diagnosing too?

[grimreaper420]

Just used the thermal camera, and can't see anything suspicious. I imagine, the other side of the board is not heating up because the fuse it blown, but weirdly the power button still works, so I'm not sure how its getting power if the fuse is blown.