Need help with Samsung LN40E550f7f
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Re: Need help with Samsung LN40E550f7f
The readings in AC mode are just error of you meter.
Try measuring your car battery in AC Volt mode to see what you get, it will show high reading. Your meter probably has simple half-wave rectifier in the AC input circuit of the meter feeding resistor networks for the meter scale.
Any way, you will need to fix the PFC circuit at this point.
Real AC Voltage of over 300VAC on that electrolytics cap would have blown the cap by now.
https://www.badcaps.net/forum/attach...6&d=1519521712
Check the RESISTANCE of the PFC diodes in both directions to see how many Ohms they will show.Last edited by budm; 02-27-2018, 09:59 PM.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: Need help with Samsung LN40E550f7f
The readings in AC mode are just error of you meter.
Try measuring your car battery in AC mode to see what you get.
Any way, you will need to fix the PFC circuit at this point.
Real AC Voltage of over 300VAC on that electrolytics cap would have blown the cap by now.
https://www.badcaps.net/forum/attach...6&d=1519521712
Check the RESISTANCE of the PFC diodes in both directions to see how many Ohms they will show.Apparently headaches/neckaches effect brain function. Anyway, I will do that first thing tomorrow and post my results. Thanks!
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Re: Need help with Samsung LN40E550f7f
At this point it is safe to say that you do have problem in that power supply/inverter driver board, you have all the correct command Voltages and other low switched Voltages but do not have the boosted Voltage to run the inverter driver circuits, we are getting there.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: Need help with Samsung LN40E550f7f
http://en-us.fluke.com/training/trai...ultimeter.html I believe you said your meter wasnt working in diode mode, this shows how to check diode in ohm mode, if you get ol in both directions try setting meter at 2000 ohm, often you get inaccurate measurement results when left in circuit. Diode should read ol in one direction, reverse meter leads and should get a reading.Last edited by nomoresonys; 02-28-2018, 06:04 AM.Comment
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Re: Need help with Samsung LN40E550f7f
Ok guys. I got my meter working properly. SO, in diode mode DP810 and DP802 both read .6v in diode mode - OL in reverse as it should I believe. However in Ohm mode I get OL both directions no matter what setting it's at. I have tested other circuits to verify ohm mode is working.Comment
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Re: Need help with Samsung LN40E550f7f
OK, then we need to look deeper in the PFC circuit section, need to get the P/N of the PFC Controller IC so we can look up the spec sheet to locate the VCC pin to see if it is getting the switched VCC for the PFC IC to run or not.
PFC IC has designator as ICP801.
Repair kit:http://www.shopjimmy.com/samsung-bn4...repair-kit.htmLast edited by budm; 02-28-2018, 01:57 PM.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: Need help with Samsung LN40E550f7f
Ok guys. I got my meter working properly. SO, in diode mode DP810 and DP802 both read .6v in diode mode - OL in reverse as it should I believe. However in Ohm mode I get OL both directions no matter what setting it's at. I have tested other circuits to verify ohm mode is working.Comment
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Re: Need help with Samsung LN40E550f7f
FAN7930B
https://cdn.badcaps-static.com/pdfs/...0db2152410.pdf
Pin 8 is VCC, Pin 6 is GND which is connected to circuit GND (negative leg of the main filter cap) of the hot side, so be real careful since you are making measurement in the HOT DEADLY side of the circuit; I suggest you to at the least plug the TV into the GFCI outlet to protect yourself.Attached FilesNever 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: Need help with Samsung LN40E550f7f
https://www.digikey.com/products/en?...G&pkeyword=&v=
Is this it?Comment
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Re: Need help with Samsung LN40E550f7f
FAN7930B
https://cdn.badcaps-static.com/pdfs/...0db2152410.pdf
Pin 8 is VCC, Pin 6 is GND which is connected to circuit GND (negative leg of the main filter cap) of the hot side, so be real careful since you are making measurement in the HOT DEADLY side of the circuit; I suggest you to at the least plug the TV into the GFCI outlet to protect yourself.Comment
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Re: Need help with Samsung LN40E550f7f
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Re: Need help with Samsung LN40E550f7f
You could exclude them in your antivirus, as in white list, lets the antivirus know that this site is ok.Comment
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Re: Need help with Samsung LN40E550f7f
Will 5 or 6 work, not sure but I think 4 says minimum purchase is 2500, you could call and ask tho.Comment
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