Hi.
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This is about DONG YANG PSU BN44-00195A failiure in Samsung 245BPLUS. It started with bang and smoke from the back of LCD. Downloaded diagram BM44-00192A - a bit different but I will use all parts names from this diagram [and real PSU].
BIG CAP CP801 had 315V, on standby pin 5,2V. After shorting S_B ON (through 3,3k ohm resistor) 24V and 5,3V were missing, on CP801 was 312V.
RM801 [real PSU: RM801 - 0,22 ohm 1W] - FAIL
burned, measured 10M ohm.
QM801 [real PSU: QM802 - FQPF5N50C] - FAIL
pins 1,2,3 shorted, measured 0,0 ohm.
TM802 [real PSU: TM802 - EE1312] - FAIL
BAD GLUE (corrosion/current) damaged wire on SECONDARY winding leg - no continuity.
Soldered missing piece of wire.
ZDB805 [real PSU: ZDB801 - BZX84C15] - FAIL
shorted pins 1 and 2,3 - measured 21,6 ohm.
CM807 [real PSU: CM806 - 47uF 50V] - NOT SURE
BAD GLUE - replaced just in case (unreliable measuring device: 47,55uF and ESR 0,66 ohm).
CB802 [real PSU: CB804 - 22uF 50V] - NOT SURE
replaced just in case (unreliable measuring device: 22,44uF and ESR 2,2 ohm).
RM810 [real PSU: RM815 - 4,7ohm] - FAIL
resistance measured 1,91M ohm.
DM801 [real PSU: DM804 - SR104] - FAIL
shorted, measured 0,0 ohm.
DM802 [real PSU: DM806 - SR104] - FAIL
shorted, measured 0,0 ohm.
ICM801 [real PSU: ICM801 - MC33067] - FAIL
after desoldering resistance between Vcc [pin 15] and GND [pin 4] had 320 ohm.
ICP801S [real PSU: ICP801S - FAN7530] - FAIL
after desoldering resistance between ZCD [pin 5] and OUT [pin 7] had 4,7 ohm.
ICB801S [real PSU: ICB801S STR-A6159] - FAIL
after desoldering resistance between GND [pin 3] and ST [pin 5] had 14,8M ohm, resistance between GND [pin 3] and Vcc [pin 2] was 15,8M ohm.
Again TM802 [real PSU: TM802 - EE1312] - FAIL no. 2
BAD GLUE (corrosion/current) damaged wire on PRIMARY winding leg - no continuity.
Soldered missing piece of wire.
Checked all windings during 1st TM802 fail and was fine but looks like it was already not good enough to work when the power from new MC33067 was on.
The rest of PSU electronic parts were fine (desoldered some of them to measure).
There was no damage to other parts like mainboard.
After replacement of RM801 and QM801 switched on mains WITHOUT "test bulb". Probably that's why so many other parts failed. Later connected "test bulb" (100W, 60 W and 40 W in parallel, one 100W bulb was not enough for fixed PSU).
BAD GLUE was on TM802, neighbouring CM806 and jumper [real PSU: J816]. BAD GLUE was yellow outside and black inside.
LCD works more than one week without issues.
Cheers!
BacCaps forum is awesome - thank YOU ALL for sharing knowledge!
This is about DONG YANG PSU BN44-00195A failiure in Samsung 245BPLUS. It started with bang and smoke from the back of LCD. Downloaded diagram BM44-00192A - a bit different but I will use all parts names from this diagram [and real PSU].
BIG CAP CP801 had 315V, on standby pin 5,2V. After shorting S_B ON (through 3,3k ohm resistor) 24V and 5,3V were missing, on CP801 was 312V.
RM801 [real PSU: RM801 - 0,22 ohm 1W] - FAIL
burned, measured 10M ohm.
QM801 [real PSU: QM802 - FQPF5N50C] - FAIL
pins 1,2,3 shorted, measured 0,0 ohm.
TM802 [real PSU: TM802 - EE1312] - FAIL
BAD GLUE (corrosion/current) damaged wire on SECONDARY winding leg - no continuity.
Soldered missing piece of wire.
ZDB805 [real PSU: ZDB801 - BZX84C15] - FAIL
shorted pins 1 and 2,3 - measured 21,6 ohm.
CM807 [real PSU: CM806 - 47uF 50V] - NOT SURE
BAD GLUE - replaced just in case (unreliable measuring device: 47,55uF and ESR 0,66 ohm).
CB802 [real PSU: CB804 - 22uF 50V] - NOT SURE
replaced just in case (unreliable measuring device: 22,44uF and ESR 2,2 ohm).
RM810 [real PSU: RM815 - 4,7ohm] - FAIL
resistance measured 1,91M ohm.
DM801 [real PSU: DM804 - SR104] - FAIL
shorted, measured 0,0 ohm.
DM802 [real PSU: DM806 - SR104] - FAIL
shorted, measured 0,0 ohm.
ICM801 [real PSU: ICM801 - MC33067] - FAIL
after desoldering resistance between Vcc [pin 15] and GND [pin 4] had 320 ohm.
ICP801S [real PSU: ICP801S - FAN7530] - FAIL
after desoldering resistance between ZCD [pin 5] and OUT [pin 7] had 4,7 ohm.
ICB801S [real PSU: ICB801S STR-A6159] - FAIL
after desoldering resistance between GND [pin 3] and ST [pin 5] had 14,8M ohm, resistance between GND [pin 3] and Vcc [pin 2] was 15,8M ohm.
Again TM802 [real PSU: TM802 - EE1312] - FAIL no. 2
BAD GLUE (corrosion/current) damaged wire on PRIMARY winding leg - no continuity.
Soldered missing piece of wire.
Checked all windings during 1st TM802 fail and was fine but looks like it was already not good enough to work when the power from new MC33067 was on.
The rest of PSU electronic parts were fine (desoldered some of them to measure).
There was no damage to other parts like mainboard.
After replacement of RM801 and QM801 switched on mains WITHOUT "test bulb". Probably that's why so many other parts failed. Later connected "test bulb" (100W, 60 W and 40 W in parallel, one 100W bulb was not enough for fixed PSU).
BAD GLUE was on TM802, neighbouring CM806 and jumper [real PSU: J816]. BAD GLUE was yellow outside and black inside.
LCD works more than one week without issues.
Cheers!
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