So the TV is powered up and turned on, then you set meter in Diode mode and put the probes on the chassis and the - pin of the LED connector, you better check to see if your meter is still OK.
You can only use Voltage mode when testing live circuit, do not use Ohm or Diode mode to test live circuit, you can damage your meter and the board.
What you did is providing the - (Cathode) return to circuit ground through your meter, instead of going through the MOSFET and current sensing resistor to circuit ground.
Show us good clear straight shot pictures of the whole top and bottom side of YOUR power supply board, and also the whole back side of the TV showing all the boards.
The picture of the bottom side has too much glare from the flash I cannot trace out the circuit using that picture.
I will have to use pictures form shopjimmy instead.
Re: Samsung UN60H6203AF LED TV Screen Won't Turn On
On the LED connector (all connectors must be in place), there are four wires so what you need to do is to turn the TV off, keep the Black probe of Volt meter (Set meter to be able to read at least 400VDC) on the chassis, read probe on one of wire then turn on the TV while watching the meter to see how high the Voltage goes up to the with 10 seconds to see what it goes down to, the turn off the TV and then repeat the same test on the other 3 LED wires.
On the LED connector (all connectors must be in place), there are four wires so what you need to do is to turn the TV off, keep the Black probe of Volt meter (Set meter to be able to read at least 400VDC) on the chassis, read probe on one of wire then turn on the TV while watching the meter to see how high the Voltage goes up to the with 10 seconds to see what it goes down to, the turn off the TV and then repeat the same test on the other 3 LED wires.
I did that the other day and, if memory serves me, it ramped up to 405v and remained for D+. S+/- was around 350v and D- 150v. I will put it back together and test again.
I did that the other day and, if memory serves me, it ramped up to 405v and remained for D+. S+/- was around 350v and D- 150v. I will put it back together and test again.
Check that diode too.
It goes up to 405V because it is not seeing the load to complete the current return.
Check that diode too.
It goes up to 405V because it is not seeing the load to complete the current return.
I checked d9001c and it passes (one direction flow only). I also checked q9001c and do not see continuity between s and d regardless of on or off state of the Q.
I checked d9001c and it passes (one direction flow only). I also checked q9001c and do not see continuity between s and d regardless of on or off state of the Q.
What does that mean?
MOSFET has body diode between S and D so when test S and D it should show like Diode.
1) Check the resistance between Source pin of Q9001C and ground to see what resistance you are getting?
2) Check the Voltage between Gate and Ground of of Q9001C.
What does that mean?
MOSFET has body diode between S and D so when test S and D it should show like Diode.
1) Check the resistance between Source pin of Q9001C and ground to see what resistance you are getting?
2) Check the Voltage between Gate and Ground of of Q9001C.
I lifted a leg of the diode and measure .4 across it. I removed q9001 and tested it as well. It shows open across d and s. I forgot to chk resistance between s and gnd before i removed it.
If i understand it right, the mosfet is bad but the diode is ok. ??? Is there anything else i should chk before ordering a ne fet?
What does that mean?
MOSFET has body diode between S and D so when test S and D it should show like Diode.
1) Check the resistance between Source pin of Q9001C and ground to see what resistance you are getting?
2) Check the Voltage between Gate and Ground of of Q9001C.
Replaced q9001c and d9001c. Still no backlight. When i first plug it is the top two rows breifly and faintly light for a split second. I checked every single led individually and they all light up correctly. Checked continuity between all led wires and the led connector and all checks out well. Measure 3ohms between s and chassis gnd. 0v between g and gnd with led connector off. 405v between d9001c and gnd with led connector off. Same voltages with led connector on. Tv off, test d+ when turned on with all connectors in place and goes up to 360vdc back down to 345vdc within 10s. S- is 260vdc down to 245vdc in 110s. S+ is same. D- is 160vdc down to 148. Running out of ideas on my end. Recall i did a bad thing by shorting the last led strip to gnd befor by using the diode mode and all the leds light up brightly. Also recall at one point this thing bit my finger when i simply touched the chassis and no points that should have done that.
Re: Samsung UN60H6203AF LED TV Screen Won't Turn On
hi maybe watch this video its a samsung un series led strip shorting too ground maybe why you got a shock of the chassis plus your led issue you are having https://www.youtube.com/watch?v=UXHyRfg1A1Q&t=192s
hi maybe watch this video its a samsung un series led strip shorting too ground maybe why you got a shock of the chassis plus your led issue you are having https://www.youtube.com/watch?v=UXHyRfg1A1Q&t=192s
That is interesting. I will try pulling the strips up and putting tape under it as well.
Replaced q9001c and d9001c. Still no backlight. When i first plug it is the top two rows breifly and faintly light for a split second. I checked every single led individually and they all light up correctly. Checked continuity between all led wires and the led connector and all checks out well. Measure 3ohms between s and chassis gnd. 0v between g and gnd with led connector off. 405v between d9001c and gnd with led connector off. Same voltages with led connector on. Tv off, test d+ when turned on with all connectors in place and goes up to 360vdc back down to 345vdc within 10s. S- is 260vdc down to 245vdc in 110s. S+ is same. D- is 160vdc down to 148. Running out of ideas on my end. Recall i did a bad thing by shorting the last led strip to gnd befor by using the diode mode and all the leds light up brightly. Also recall at one point this thing bit my finger when i simply touched the chassis and no points that should have done that.
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