UA55JU6600KXXA SMPS -> PCB Main

[Jewdo064]

Hi. I would like some help with some things, if anyone would be kind enough to assist me.

The SMPS board of the UA55JU6600KXXA, (part number BN44-00807B)
the cable that powers the main board of the TV. what are the volts supposed to be at? Where can I find this info?

I have no electrical experience or degree, please keep that in mind.

I was trying to figure this out, but I have a feeling I am way off with my theory:

CNM08 only shows one key, thats a13v. Im not sure what that means.

CM802 shows ''power output'' a13v (12.8v) 4.7a

So what I am thinking is, what they are saying: the wires that are labled as a13v, should read at 12.8 volts? Please feel free to have a laugh

The TV does not post, panel does not light up. When removing power to PCB main, panel lights up blue.

I dont care for a diagnosis on the TV, I wish to know what the volts should be at on that cable, and if I could read those keys and understand them. Shit that would be great.

Thank you in advance

Jew

[Khron]

Re: UA55JU6600KXXA SMPS -> PCB Main

"A13V" is only the name of the signal. If, in the second table, it says it should measure 12.8v, then that's what it should normally be. Simple

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

Thank you.

The voltage readings I get are all between 3 and 5 volts, and is supposedly, supposed to be, at 12.8v.

Which means the smps is faulty.

What is most likely to be the cause of a lack of power like that, a faulty transformer id imagine, am I correct?

From what I googled yesterday, the transformer is not easy to replace, and or, not worth it. So I will just replace the board. I would like to test the transformer though, for learning purposes. Does anyone have a nice guide I could read, on how to test the transformer of a smps? and what is a smps transformer called? I know the old big ones are called a linear transformer

Case closed though! Thanks for your help

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

I think I am doing something wrong.

I replaced the panel of a different TV, that is completely working now. (UA55JU6000KXXA)

It uses the exact same SMPS (part number BN44-00807B) and a13v is supposedly, supposed to be 12.8 volts.

So I measured the volts on the power cable to the PCB main, and it doesn't even read @ half those numbers?

Am i even measuring the volts the correct way ? (please see attached image - I was informed / instructed, how to measure the volts, via a guide I found online)

[Khron]

Re: UA55JU6600KXXA SMPS -> PCB Main

Ehrm... What signal lines are you probing there?

Supply voltages are usually measured referenced to ground / 0V.

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

I keep the black rod on the side with the grey cable, which usually means #1
The red bar I am probing all of them one by one, none of them, on either side, gives me 12.8v :what:

Do you still want me to check which one I was checking? lol

EDIT the black is on the ground line yea

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

There is nothing to solve, I just wish to know how to test a SMPS output. (Samsung specifically)

Is there no one who can do this? Dem Koreans to weird for yous?

[joshnz]

Re: UA55JU6600KXXA SMPS -> PCB Main

they are not that hard to test but if psu is not told to be on for instance the cable connected to the main board is unplugged the voltages will not be correct.

[budm]

Re: UA55JU6600KXXA SMPS -> PCB Main

It is easier to use chassis GND and the GND ref. for the meter's Black probe, one thing is that your probe is really making contact with the terminals of the connector?
Also when you see in SAMSUNG TV: 'AxxV' A = Always Voltage = Always ON power supply.
'BxxV' = Switched Power supply = it will be present only when the PS-ON (POWER-ON) command signal from the main board is present.
When the output Voltage is fluctuating then it can be due to bad startup/running cap (very common failure), bad Voltage from the main filter cap, bad output filter caps, bad rectifier diode, bad solder joints, etc. that is why you have read the circuit and start checking out the components and the Voltages in the circuit. The bottom line is you need to know how the circuit function first.
Pictures provided by shopjimmy.
BTW, the 13V power supply (produced by rectifiers D853C, 854C) is not tightly regulated, +/-2% for that 13V is fine.. Also there is error on the chart, one chart show Vamp, the other chart does not have Vamp. There is no Vamp pin on the actual connector, pin 3, 5, 7, and 9 are all tied together for the A13V which you can see on the bottom side of the board.

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

Thank you for the input.

I have some questions:

#1. Is my numbering charts correct? Please check reference image labeled " Numbering system " and " 3, 5, 7, 9, PCB "

#2. Is it safe to probe the 4 middle lines, as indicated on reference image " 3, 5, 7, 9, PCB "? and if it is indeed the correct method and or safe, where do I put the black probe? I see no earth on the chassis, everything is connected, check reference image labeled " Where on earth.. " if needed.

#3. Reference image " Rectifiers 1 " are the rectifiers mentioned? (that control he power output to the PCB MAIN) This is identifiable because of the STB 8v (Stand-by 8v) and ON 13v key, printed in between them? (I am trying to read the circuit flow / function - there is allot I do not understand yet though - There are some things that seems to be logical, like this one, and the direction its going to the 12 pin connector)

#4. Assuming the power board is 100% fine, fully functional and working.
Where do I put the red probe, and where do I put the black probe, to get 8v on stand by mode, and 12v when power is on ? xD

Thank you so much! I am trying to learn and understand.

I do not just want to stick the probes everwhere, because I know nothing of electronics, and I am scared I will blow up, or atleast the smps.

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

(1) It is easier to use chassis GND and the GND ref. for the meter's Black probe, one thing is that your probe is really making contact with the terminals of the connector?

(2)Also when you see in SAMSUNG TV: 'AxxV' A = Always Voltage = Always ON power supply.
'BxxV' = Switched Power supply = it will be present only when the PS-ON (POWER-ON) command signal from the main board is present.

(3)When the output Voltage is fluctuating then it can be due to bad startup/running cap (very common failure), bad Voltage from the main filter cap, bad output filter caps, bad rectifier diode, bad solder joints, etc. that is why you have read the circuit and start checking out the components and the Voltages in the circuit. The bottom line is you need to know how the circuit function first.

(4)Pictures provided by shopjimmy.
BTW, the 13V power supply (produced by rectifiers D853C, 854C) is not tightly regulated, +/-2% for that 13V is fine.. Also there is error on the chart, one chart show Vamp, the other chart does not have Vamp. There is no Vamp pin on the actual connector, pin 3, 5, 7, and 9 are all tied together for the A13V which you can see on the bottom side of the board.

1: I cannot find a ground, outside of the 12 pin connector. Hmm, I think so, its giving a volt reading, doesnt that make it safe to say yes? (honest question)

2: 'BxxV' Is that the type of boards Joshnz was speaking about? The type of TV / SMPS, that the PCB MAIN must be connected to get a accurate volt output reading? (This is a ''always on'' case, for the record)

3: I can respect that

4: What on earth is Vamp? Please tell me if it is important, and you have the ability / time to explain.

[budm]

Re: UA55JU6600KXXA SMPS -> PCB Main

A13V = always on Voltage, it means that the minute you apply AC power to the board the 13V will be present without turning on the power switch.
B5V (EXAMPLE) will be present when the main board sends the COMMAND PS-ON signal to turn on the B5V power supply section.
https://www.badcaps.net/forum/attach...9&d=1474451132

Do you see the white square marking on the pin to the right of the connector? That is marking for pin #1, same system as the IC. The row of pins of the connector that you see on top of the board are the ODD number row pins, so counting from the right, the last pin on the right is pin 1, then pin 3, 5, 7, 9, 11 (which you can clearly see '11' right by the pin).

"I do not just want to stick the probes everwhere, because I know nothing of electronics, and I am scared I will blow up, or atleast the smps."
Then you should nit be trying to troubleshoot something this complex down to the component level, you need to know the basic electronics first so you will at least know how to test Voltage, resistance, and current and most of the SAFETY PRECAUTION that you must follow, if you need to ask then for sure you should not be trying to troubleshoot the circuit board for now, just do the boards swapping until you learn more about electronics, once you have good base knowledge of electronics then you can apply that on just about anything that have electronics circuit in it. Transistors, diode they operate the same way in TV or in computer or in cars.

https://www.badcaps.net/forum/attach...0&d=1474385038
Do you see those 3 metal rings on the power supply board where the screws for mounting the board to the chassis are? Those 3 rings have connection to the circuit ground so when the board is mounted to the metal chassis the chassi then become GND ref. point for the cold side of the circuit.
If the AC power cord has three wires, then the SAFETY Ground wire (Green wire with Yellow stripe) will also be attached to the metal chassis.
I use the chassis as the GND ref. point for the Black probe of the meter (the circuit Ground of the cold side of the power supply is connected to the metal chassis that is why you can use the chassis as the Ground ref. point for the meter), or use the Ground plane of the board, if you have to ask what Ground plane is then you need to learn basic electronics and learn how to read and understand the schematic first, and sine you have internet you can easily find the answer on the internet.

'Vamp' marking in SAMSUNG board means the DC Voltage for running the Audio Amplifier circuits (V = Voltage, Amp = Amplifier).

'#4. Assuming the power board is 100% fine, fully functional and working.
Where do I put the red probe, and where do I put the black probe, to get 8v on stand by mode, and 12v when power is on ? xD'

At the A13V pin (you can easily see how those two diode are connected and how they are related to the A13V pins of the connector), but in this case the STBY =8V may not be applied. If you look at the board, you can see that not all the components are installed on the board, that is because the board can be stuffed parts as need for other model of TVs, so the STBY:8V may not be applied to the board you have, but you can check easily check that Voltage on the A13V pin to see what you get when the TV is not turned on and when it is turned on.

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

"I do not just want to stick the probes everwhere, because I know nothing of electronics, and I am scared I will blow up, or atleast the smps."
Then you should nit be trying to troubleshoot something this complex down to the component level, you need to know the basic electronics first so you will at least know how to test Voltage, resistance, and current and most of the SAFETY PRECAUTION that you must follow, if you need to ask then for sure you should not be trying to troubleshoot the circuit board for now, just do the boards swapping until you learn more about electronics, once you have good base knowledge of electronics then you can apply that on just about anything that have electronics circuit in it. Transistors, diode they operate the same way in TV or in computer or in cars.

Thank you for all your help and input. That being said

I have been replacing boards for 5 years and I am over it. I have researched how to test diodes, caps, resistors, transistors, etc. and have applied that knowledge to test things like resistors, with great success. But now I am stuck with something, that I don't quite understand, so I am asking for help.

Usually when you don't understand something, you ask. Knowing how to test the output voltage does not sound too complex to me. No one is forcing you to answer my noob questions, feel free not to. It is not your place to decide for me, what is, and what is not, too complex. If you are serious about this piece of crap of advice, please do tell me. Where do I start, what do I read? I have read up about most of the basic components, but still claim to know nothing, because I don't. Also I put allot of effort in my questions and thread. Eventually it is time to move on to practicals. Thank you for killing my vibe and thread.

Now go help some professionals.

[budm]

Re: UA55JU6600KXXA SMPS -> PCB Main

'Where do I start' So many free info out there. You have no idea how lucky you are to be able to access so much information from around the around world compared to what I had 40 years ago.

Some examples:
http://101science.com/Radio.htm
https://cdn.badcaps-static.com/pdfs/...9d2f320fd0.pdf

Search: 'how to read schematics', 'how to read schematics pdf'

https://cdn.badcaps-static.com/pdfs/...45cfef8e50.pdf
https://cdn.badcaps-static.com/pdfs/...2e71ddea17.pdf

Download the schematics and practice on how to read them.
http://www.toms-service-manuals.com/...&Search=Submit

Search: Examples
'how does transistor work'
'how does MOSFET work'
'how does DIODE work'

BTW, building power supply is a good way to learn how to test Voltages, how the Transformer, Diodes, transistor, and caps work and how they are being used in the circuit.
Examples: 'linear regulated power supply using transistor and zener diode'
http://www.bristolwatch.com/ele/zener_power_supply.htm
http://www.learnabout-electronics.org/PSU/psu22.php
http://www.radio-electronics.com/inf...ry-circuit.php

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

Thank you for the link resources. Like I said, I did read up on allot of things, mostly how to test components and check if they are faulty. Learning to read schematics and have a solid back bone of knowledge is good, I agree with that. But that takes time. You cannot say I do not know how lucky I am. I might be old as hell to. (i'm not, but we literally still used dial up a few years ago where I am from - and pay out our ass for underwhelming internet)

I will read through those. Even then I will still ask dumb questions, because while it has some info / allot of info, it still does not have everything, and cannot explain to me when I have a question or do not quite understand. For example, it doesn't have the schematic for the ht-e330k dvd smps. (which I was trying to figure out why the fuse keeps blowing) and before I have a solid back bone of knowledge, I can still test components and replace them if proven faulty.

Enough of the banter, I will read the links and figure this stuff out myself.

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

Oh and the building up of a smps is actually a good idea, ill try that too thanks

[zx8401]

Re: UA55JU6600KXXA SMPS -> PCB Main

Make sure the screws that hold the psu pcb down are not loose, under some screws are tracks that need to be connected to the chassis, it can affect operation.
Sounds silly, but some tv's wont work correctly :-)

[Jewdo064]

Re: UA55JU6600KXXA SMPS -> PCB Main

Alright ill keep in mind, thank you