Mulja tv repair portal
Equipment Repairs => PLASMA TV forum => Topic started by: Motsey on March 23, 2011,15:49:55
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Hi I have a samsung ps-42q7hd which is not responding no lights/leds or anything and was wondering any anyoe could give me some guidence on testing the psu (it is model number PSPF441A01A) to see if itis working right and thus eliminating it as a fault.
I would really appreciate any help at all.
I can add pictures etc if you would like.
-Thank you
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Update.......
Just measured on a lead coming ou of the psu to the main board and the stb-%v is all over the place wont sit still
also D5.3V & D12v both give no reading at all.
Any idea guys? New psu?
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Also this looks like someone has previously tried to solder it but dont a bad job on it - pics included
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need a full piccie of power supply please.
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hi id have a look on ebay for a psu see how much they are and see if its cost effective to just replace or repair sounds like a psu issue to me .dave
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Hello,
If the stand-by 5V supply is fluctuating, this is worth a check, before replacing the complete power-suppy.
It's normally a separate supply to the main, using a small transformer to supply the 5V.
Check the normal electrolytics, etc.
Regards
John
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Hello,
If the stand-by 5V supply is fluctuating, this is worth a check, before replacing the complete power-suppy.
It's normally a separate supply to the main, using a small transformer to supply the 5V.
Check the normal electrolytics, etc.
Regards
John
Thanks for your replys everyone
*I dont have a small transformer to supply the 5V - the electrolytics all looks fine to me
* I will get pic's done later on tonight for you
* Had a look for the board and it is expensive = £89 / 144.620$US and thats abit high for me at the moment
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Sorry for the late reply here are some pictures of the main power board - let me know if they are ok or if you would like me to take more, if so which bit and whats best way of doing it eg Zoomed in close up.
Hope someone can work out what I could do/try to get this board working - Im up for trying almost anything.
-Thanks
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more pics but this time zoomed in so there are 3 pics which were taken kind of side by side - they might need piecing together but i didnt want to attempt incase i ruined the quality.
-Thanks
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Are thesepictures ok or would you like me to take others?
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Hello,
Check around this stage - see photo.
Regards,
John
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Check 5 volt on that diod and replace this two capacitors
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Thank you very very much really appreciate it - i will try and get this done some time this week, just had abit of bad news so might have to do it next week
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Hi Guys...
I have a similar problem on the SAME power supply board.
My problem is that when swithing on the tv I just get a clicking sound and the tv will not turn on.
The pictures in this thread are the same as my power board.
I have visually checked all the capacitors and non of them seem to be dodgy. i.e. they all have flat tops.
Has anybody got any ideas how to cure this problem ???
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hello again guys unfortunately im back as its gone again but a different problem this time - its got the clicking and flashing blue light issue.
None of the capacitors looks blown but I have replaced a few of the capacitors that I had and it made no difference - should i just order the rest and replace them as well just to be sure?
Could it be anything else? :c017:
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hi mate wasnt there an eeprom issue with sammys just switching on and off ? sure i heard this or something similar on here .dave
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Ahh yes i remember reading that awile ago!
I had an accident, well I was totally stupid - I was testing the power board and plugged it in but it ended up touching something metal and shorted :03: There is a burnt mark there and it wont power on!
Ahhh soo annoyed off with my self - going to have a look at the board closer and see if I can work out which components are damaged and if the board can be brought back to life.
Does anyone know where I could source a replacement power board from? I cant seem to find any in stock anywhere at the moment.
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hi mate gutted for ya .have you checked ebay ? .dave
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Yes had a look on ebay and no luck - Im going to look at the board in more detail when I get some time this weekend and see if I can revive it x fingers crossed
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Was looking at the power board today and noticed a fuse was measuring 0 and thankfully changed the fuse and its back to where it was before my stupid mistake - so now back to flash blue light
hi mate wasnt there an eeprom issue with sammys just switching on and off ? sure i heard this or something similar on here .dave
I have followed these instruction ;
1. Short out the eeprom pins 5 & 6 ( the two legs with the resistors ).
2. Turn on the power. - Instead of the usual noticeable relay click, you get a faint click, the backlight stays off, nothing else happens.
3. Wait around 1-2 secs ( anything longer than this NEVER seemed to work ).
4. Remove the short
5. Press info,menu,mute, then power - In that order individually, one at a time.
6. TV should come on with noise picture and the service menu.
7. Navigate to reset to go back to factory defaults and you're away....
I have done 1,2,3 & 4 and when I try 5 the tv just keeps flashing
I had it on its back open and was pulling out different leads and testing it and it worked sometimes but if I try it again with that same lead out then it wont work - strange
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Just noticed when I remove the "LJ41-03439A Y SUS" the tv boots up/makes the noise of loading and the led stops flashing!!
Is there any known problems with this part or things to check?
I hope im moving a step closer :dubbio:
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How would i remove the Y-MAIN Board LJ41-03439A apart from the LJ41-03440A Buffer? They are connected with clips? but im worried about forcing them apart just in case i damage the boards.
I want to seperate them to test the main board on its to hopefully eliminate the buffer board as faulty.
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Managed to seperate them, it was fairly and a little brute force
The main board didnt work on its own but ive decided to replace both but am struggeling to find them both for a decent price.
does anyone know any sellers who sell parts for a good price? I need LJ41-03439A & LJ41-03440A
-Thank you
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I tally a samsung ps-42q7hd which is not responding no lights/leds or anything and was wondering any anyoe could stretch me any guidence on investigation the psu (it is modeling separate PSPF441A01A) to see if itis employed aright and thus eliminating it as a accuse.
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Good news guys I replaced the LJ41-03439A & LJ41-03440A board and its working perfect, if not better, then it was before.
I will write a small guide on how I figured out the problem and what things I noticed soon to help other people out but this just proved that a flashing light is not always only a cappicators/PSU issue.
-Big big big thank you to everyone
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more pics but this time zoomed in so there are 3 pics which were taken kind of side by side - they might need piecing together but i didnt want to attempt incase i ruined the quality.
-Thanks
ive got the same problem. except i got carried away i found a slightly loose capcitor, samyoung kmx 22uf 450v (gold and black) accidently soldered backwards, blew a fuse. now theres no sign of life. im in the process of repacing that capacitor.
anyone think ive fried something else?
all the other capacitors look fine