Hello all. Currently trying to fix my nieces tv. Has no video. She did her own research and did the flashlight test. then ordered a replacement inverter. I installed it, however it did not fix the problem. There are no swollen caps. I suspicion the power supply board, but I need a schematic or other assistance in testing. Yes, I have a multimeter and a usb oscilloscope however, I don't know how to use the oscilloscope yet. Have searched and searched for service manuals, schematics, etc. to no avail. The power supply board is a BN44004400B. Thanks!
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Re: Need help with Samsung LN40E550f7f
pretty smart niece to figure that out it could be the inverter board. However for your board is a PSU repair kit at SJ available that fixes: The Samsung BN44-00440B Power Supply Component Repair Kit includes all necessary components to repair common failures on the Power Supply. Symptoms include will not turn on, no backlights, missing 5V standby or PFC.
http://www.shopjimmy.com/samsung-bn4...repair-kit.htm -
Re: Need help with Samsung LN40E550f7f
So what Voltages do you have on the connector of the power supply board that goes to the main board when TV is in standby and when power switch is activated?
You MUST report the pin name and follow by the Voltage reading for each pin so we can see if they are correct or not.
We also need good clear the pictures of YOUR whole power supply board.Last edited by budm; 02-19-2018, 06:19 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
Exercise caution when testing power supply board, it can be deadly. there are legends like little maps on the power supply board that tell you what voltages to expect from the connector pins, put negative lead on ground like the chassis for example, also check those 2 fuses if you haven't, I check those fuses with tv off and unplugged. The voltages have to be checked with tv on or plugged in of course.Last edited by nomoresonys; 02-19-2018, 09:42 PM.Comment
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Re: Need help with Samsung LN40E550f7f
Thank you for the input. I will consider that option if it turns out to be the problem.Comment
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Re: Need help with Samsung LN40E550f7f
Voltages are as follows both on the power supply as well as the lead in to the logic board:
Power supply:
Pin 1=5.17
2= 5.17
4= 12.78
5.=12.78
6.=12.78
7.=12.78
At Logic Board= same
Lead to inverter:
pin 10= 12.07
pin 2= 12.76
At Inverter: Same
Any not listed had value of 0.Attached FilesComment
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Re: Need help with Samsung LN40E550f7f
If you do post voltages and pin numbers, you have to include the pin out name. Your pictures are way too small in order to see anything like that what we need. You need to upload high resolution pictures, so we can see the details.Comment
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Re: Need help with Samsung LN40E550f7f
1) No pin names to tell us what each pins are.
2) There are 14 pins on that power supply connector that goes to the main board but you only report 7 of them and without the pin names as requested then those reported numbers are just about meaningless.
3) Samsung BN44-00440B power supply board?
4) You need to follow the instructions.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
Don't give up, what I do is just copy the legend/map on a piece of paper, pins and description, like bl-on etc, then just type it back in here with the voltage you got next to it.Comment
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Re: Need help with Samsung LN40E550f7f
http://www.shopjimmy.com/samsung-bn4...upply-unit.htm is this your power board? you may have gotten a bad tcon board, hard to tell, I see shopjimmy has 1 for 10 bux. oops my bad you said inverter not tcon.Last edited by nomoresonys; 02-20-2018, 08:54 PM.Comment
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Re: Need help with Samsung LN40E550f7f
Does this tv have a metal back cover? if so are there any burn looking marks on it, like where the power board is etc. just worked on a sammy ln40c650, you can check my thread if you care to, but take your time, I double and triple checked everything before proceeding, you may have a whole different issue of course.Comment
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Re: Need help with Samsung LN40E550f7f
Maybe start with those 2 big 450v filter capacitors, check m with black lead on negative side and red lead on positive side right on the legs, should get around 160 in standby and 380 volts while tv is on.Comment
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Re: Need help with Samsung LN40E550f7f
I see now what you guys are talking about in regards to pin names. Will upload along with new pics.Comment
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Re: Need help with Samsung LN40E550f7f
psb:
1. B13V -13.1V
2. DIM- 5V
3. B13V-13.1V
4. NC -0V
5. B13V- 13.1V
6.BLU_ON -0V
7. B13V-13.1V
8., 9., 10 GND- 0V
11.B5V- 5.1V
12 A5V - 5.1V
13. B5V- 5.1V
14. PS_ON- 3VAttached FilesComment
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Re: Need help with Samsung LN40E550f7f
Here's a better one.Attached FilesComment
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Re: Need help with Samsung LN40E550f7f
No scorch marks. 450v caps read 375v. Everyone is talking about standby mode; on this t.v. , when is off, the indicator light stays red and I have no readings. If I turn it on, it chimes, the light flashes and then goes off. After several minutes, it shuts off.Comment
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Re: Need help with Samsung LN40E550f7f
Don't have a schematic, not sure if this one will do it, try unplug power supply board from main board, see if backlights go on.Comment
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Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
Hey everyone,
This power supply board is hard to find but there are repair kits available. This board had a blown fuse, FP801S, blown PFC MOSFET, QP802CS and ceramic cap, CP809. I replaced them with parts I already had and tested the rest of the parts that would've come in the repair kit and they were fine. I powered the board up on the bench expecting, in typical Samsung power supply board fashion, to see all my output voltages but, nothing. 0 volts on CNL801, CNM801 and CNT801. The only thing I have is 170vdc on the filter caps. No standby voltage either.
Anybody... -
I did not have any 27uf @ 50 volt capacitors but one nice thing is that it has enough room for two capacitors in parallel a 22uf and a 4.7uf @ 50 volts 22 plus 4.7 equals 26.7uf which so very close to 27uf I will show some pictures of it sometime tomorrow
This is one of the shit est boards I seen in a very long time and it was the daughter board the traces just lifting off the board I had to use the capacitor leads to repair the the traces and the main board is not any better because I had to repair several traces for the daughter board to the main board
After all of... -
Hi, this is my personal laptop, which the original board (lets call it Board A) blew up PU8700 (TPS51486), making a hole on the board, i had left the laptop at my desk one day with the battery fully charged and didn't touch it for a week, but when i tried to turn it on it didn't
Thought the battery was dead, so i plugged in the charger then tried to power on, the power LED blinked once, charged LED still orange, unplugged the charger, plugged in again and I noticed the "magic smoke" smell, so i unplugged the charger, removed the back cover and saw the blown IC (the "magic... -
I hope this is the right forum to post in despite not technically being a repair, but still a question of swapping boards.
I thought I'd explore the possibility to upgrade an existing working Samsung ue55nu7096u with the logic board (and power board if needed) of a newer model (ue55ru7105k) of the same size and appearance (and resolution). The reason being I'd like the extra inputs of that board including component in, an extra HDMI port and bluetooth. Its panel is broken so I have no use for the board otherwise.
The models launched in 2018 and 2019 respectively....
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