Samsung PN59D6500 power cycling where to start?

[pbiancardi]

Just got a cheap PN59D6500 on Craigslist, seller described as power cycling and non responsive. I got it home and it worked fine, was able to play a movie start to finish from built in Netflix app. I also updated the firmware to 0018 (shortly after this the power cycling started, coincidence I'm sure since seller had an issue also).

Now the problem presented itself to me, it shut off on its own and now just keeps trying to power on but doesn't.

I have read that this model might be more likely to need a main board than a power board, can anyone tell me what I should start looking at first? Does the fact that everything worked fine for a couple of hours tell me anything?

[sordids999]

Re: Samsung PN59D6500 power cycling where to start?

Posting pictures of the back of your tv showing the boards with clear pictures may help you more with fixing your problem

[ReeceyBurger123]

Re: Samsung PN59D6500 power cycling where to start?

Maybe do some research on hoe to test Plasmas and Pson voltages.

[pbiancardi]

Re: Samsung PN59D6500 power cycling where to start?

Posting pictures of the back of your tv showing the boards with clear pictures may help you more with fixing your problem

Here you go, I don't see anything bulging.

[vinceroger69]

Re: Samsung PN59D6500 power cycling where to start?

I would check the power supply maybe resolder all the parts/components on the heatsinks and check for any bad/cracked jpints on the rest of the board then carry out the tests in the video and leave running on the test patterns does the tv still shut off at the same time period?
https://www.youtube.com/watch?v=JjrwTZC5nVg

[pbiancardi]

Re: Samsung PN59D6500 power cycling where to start?

I would check the power supply maybe resolder all the parts/components on the heatsinks and check for any bad/cracked jpints on the rest of the board then carry out the tests in the video and leave running on the test patterns does the tv still shut off at the same time period?
https://www.youtube.com/watch?v=JjrwTZC5nVg

I tried resoldering but it doesn't even get to standby mode, as soon as i plug it in it tries to power and and starts cycling?

Honestly I am capable of small repairs but probably not troubleshooting, what board seems like I should try swapping first, the main or power? It's very likely ome of those correct?

[ReeceyBurger123]

Re: Samsung PN59D6500 power cycling where to start?

Seems to me like a mainboard issue, like corrupt firmware or bga solder. Please test what voltages I have asked you to. Including with the set working and when it fails:

Vson
Pson
Vs
Va

[pbiancardi]

Re: Samsung PN59D6500 power cycling where to start?

Seems to me like a mainboard issue, like corrupt firmware or bga solder. Please test what voltages I have asked you to. Including with the set working and when it fails:

Vson
Pson
Vs
Va

Pson goes from near nothing to 3.28
Vson also goes from zero to 3.28 while power is trying to turn on

I don't seem to get anything from VS or VA but realize TV never actually powers on its cycling the entire time.

Sorry meter set wrong va is 55 and vs 190 at a certain point in cycle.

Va stays consistent vs spikes at 194 then drops to zero. This is all while TV is cycling, it never kicks on.

[pbiancardi]

Re: Samsung PN59D6500 power cycling where to start?

If I jumper everything and try to get the test patterns all I get is a blank screen, also at this point VS is zero??

[ReeceyBurger123]

Re: Samsung PN59D6500 power cycling where to start?

Your sustain boards are shorted. Remove the Ysus connector and Xsus then measure for short circuits on the power transistors.

[pbiancardi]

Re: Samsung PN59D6500 power cycling where to start?

Your sustain boards are shorted. Remove the Ysus connector and Xsus then measure for short circuits on the power transistors.

Isn't there a test to unplug one at a time to narrow down which board to look at?

Is this worth fixing?

[ReeceyBurger123]

Re: Samsung PN59D6500 power cycling where to start?

No, helps if you search the forum on how to test Plasmas. These sets if it detects Vs is not loaded or is being heavily stressed (due to short) it turns vs off. Worth fixing though as these look good when they work. Also you should test the sustain voltages like Vsc and Ve on the sustain boards.

[pbiancardi]

Re: Samsung PN59D6500 power cycling where to start?

No, helps if you search the forum on how to test Plasmas. These sets if it detects Vs is not loaded or is being heavily stressed (due to short) it turns vs off. Worth fixing though as these look good when they work. Also you should test the sustain voltages like Vsc and Ve on the sustain boards.

Ok I'll do some reading and check back in once I do as you said thanks.

[ReeceyBurger123]

Re: Samsung PN59D6500 power cycling where to start?

Ok cheers, let is know what voltages you get.

[pbiancardi]

Re: Samsung PN59D6500 power cycling where to start?

Ok cheers, let is know what voltages you get.

Ok still not certain I am doing it correctly but when I test the two outer pins on the transistors of the first board I removed, all readings are basically the same (about 10 when the ohm scale is set to 200k) except the two in the picture, one shows open line and the other is reading about 1/2 of the rest. Is this my issue (or at least an issue)?

[ReeceyBurger123]

Re: Samsung PN59D6500 power cycling where to start?

Does your meter have diode mode ? Its easier to find short circuits with that instead buddy.

[pbiancardi]

Re: Samsung PN59D6500 power cycling where to start?

Does your meter have diode mode ? Its easier to find short circuits with that instead buddy.

No but I can buy one, wouldn't what I did show those are bad?

[ReeceyBurger123]

Re: Samsung PN59D6500 power cycling where to start?

Transistors like that rarely ever ever fail open circuit. You could put the board back in though and test its voltages such as Vsc and on the other board on the right hand side of the screen (xmain) test Ve voltage.

[pbiancardi]

Re: Samsung PN59D6500 power cycling where to start?

Transistors like that rarely ever ever fail open circuit. You could put the board back in though and test its voltages such as Vsc and on the other board on the right hand side of the screen (xmain) test Ve voltage.

I broke one of the ribbon cables that plug into the left side of the Y Sustain board, is that replaceable?

[ReeceyBurger123]

Re: Samsung PN59D6500 power cycling where to start?

The ones going into the panel ?