I have a Visio VO47L FHDTV10A with no backlight. I happen to have a spare, known good, PSU and main board. I have replaced the master inverter as it showed physical damage to the IC, and replaced the caps on the slave as they were bulged and way out of spec. I still have no backlight and before replacing the slave inverter i would like to be able to verify that it is bad. Can anyone explain how they function? they are connected to each other through ribbon cables and a wiring harness. They both have 24V to them but I dont know how the master signals the slave to fire. I just want to make sure I didnt get a bad master before replacing the slave as it costs twice as much. Thank you!
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Re: VO47L master / slave inverter help
Pictures of the inverters would help, many times there are small fuses on the inverters, Also take a close look at the slave ic, I have seen where the supply pin to the ic is discolored (black) indicating it drew too much current (shorted ic) also check the fets for shorts. -
Re: VO47L master / slave inverter help
The Master /Slave inverter setup is setup as a push-pull (drive signal is 180 deg out of phase from each other) to be able to drive long lamps. The master provide the out of phase drive signal to the salve.
If the master inverter is working, and the slave is dead, you will see the lamps light up half way the screen then the protection will kick in, if the master inverter output is bad (but the controller IC is good) and the slave is good then you will see another half of the lamps light up and then the protection will kick in.
So you can disconnect the power supply cable to the slave and then look at the screen real close in the dark room to see if the screen lights up for seconds or not first when you first turn on the TV.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: VO47L master / slave inverter help
https://www.badcaps.net/forum/showpo...4&postcount=39
Look at page 47, 51 for the concept on how MASTER/SLAVE Inverters functionNever stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Merry Christmas
Does anyone know how to bypass the protection ic OZ9928SN on a LG 47LG5000 inverter using a I470H1-20A MASTER pcb?
Pictures attached
Thanks in advance...12-26-2024, 05:25 AM -
My cheap crappy 1KW grid tie inverter (GTI) seems to keep blowing IGBTs. When I first got it, it had two failed IGBTs. It used four 60N100's (TO264). I bought 5 from a dubious source (fleabay) and replaced just the two that were dead. The GTI worked for almost two years but recently one of the two that I replaced failed. Since I had three spares, I replaced the dead one. Then a few weeks later it failed again. Weird. Well since I bought dubious China-sourced IGBTs from fleabay it could very well just be a mixture of fakes. I replaced it, but then a day later it failed again! I put in the last...
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I just got this tv today and it appeared to have no backlight on. After taking off the rear cover and checking again in the dark I can see that MAYBE one quadrant is lit.. But still it's quite dim. I was going to check the LEDs with my tester, and I found LED 1 and LED 2 + pins on the wire from the inverter, but I couldn't identify a ground. Nonetheless I tried using a mounting screw on the inverter board and also the chassis as ground but regardless my tester reads 300 which is what it reads when there is no voltage draw.
I don't know how exactly to test the inverter itself. Is it... -
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The service manual () says this is a “DET_10V error: UR10V or A9V is not applied”, but after checking several voltages I believe the power unit is tripping off due to an overload as soon as the backlight tries to come on; this kills... -
origanlly the backlight would come on and go off in my great ability to repair I hooked up a test light per instructed master side top 6 would only partially light slave side lit test light fine, pulled tv down to bulbs, same bulbs inside only halve lit. seems master inverter at fault tested all transformers all seem fine, pulled top transformer from master double checking test points reinstalled cleaned up all connections noted on back of master center of board dark spot, checked around that area everything on top of board seems fine, resoldered the 0 resistors plugged everything back in turned...07-16-2016, 02:32 PM
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