Samsung PN50b550T2FXZA Big disappointment

[R1racer]

Re: Samsung PN50b550T2FXZA Big disappointment







Thanks for all your help

[awyatt2]

Re: Samsung PN50b550T2FXZA Big disappointment

bottom pick near the bottom, that discolored spot get a magnifier on it I think it looks funny may be a bad solder ring or joint. check every discolored place on the board a lot of heat there. do you have or have access to an esr meter? push comes to shove take a pencil with eraser and push on the top side to try and find a broken joint. these are good TV's I have one on now. the four spots I see look like a bright spot over a duller solder ring.

[awyatt2]

Re: Samsung PN50b550T2FXZA Big disappointment

do you have a 47uf 50v electrolytic cap? if you do locate cp816 and replace it to see if the pfc is starting. just to rule it out it needs to be low esr, probably use a std for test purposes but I wouldn't trust it long term.

[R1racer]

Re: Samsung PN50b550T2FXZA Big disappointment

In Pic one near the transformer I poked with a pencil tip and one solider joint sunk it's the solder near the tip and joint ..!

Down farther pic 3 I found one diode not showing appears to ha e hole in the Middel of the solder around its leg but I won't call it cold solder but strange thing could happen.


I don't have access here to ESR meter but some of my crew at work might


I was able successfuly to locate the cp816 near the heat sink .. Might try to locate similar value . Unfortunately I have to head out of town and stop all the trouble shooting excitement until I return Wednesday.

I truly appreciate all your time and guide thru this .. I will keep the thread a alive once I get back

I also found that they sell a PS repair kit contain caps , and few
Other component not sure if it's worth buying

[ReeceyBurger123]

Re: Samsung PN50b550T2FXZA Big disappointment

Only check the solder joint of the devices mounted on heatsinks others will be fine. Also as fuses are good you probably have the 5vstby fault seems common on these, repair kits are available.

[R1racer]

Re: Samsung PN50b550T2FXZA Big disappointment

Only check the solder joint of the devices mounted on heatsinks others will be fine. Also as fuses are good you probably have the 5vstby fault seems common on these, repair kits are available.

Fuses are good .. Checked them few times

No 5v STBY at all ..only time I get the set to power and 5v present for short time is when I chill the SMPS . Is there a way to test them 3 legged component ( not sure what sure on the correct term) mounted with flips screw to the heatsink

[awyatt2]

Re: Samsung PN50b550T2FXZA Big disappointment

yes there is a way to check the 3 legged components but you have to know if they are diode,fet,npn,pnp to know how to test. shop jimmy also has the repair kit unsure as to whether it would do you any good as to components if indeed it is a cold solder joint though. resolder all suspect joints and see what happens. if you need trhe print on the ps I have it in pdf form.

[ReeceyBurger123]

Re: Samsung PN50b550T2FXZA Big disappointment

Those joints you said are riveted they wont be lose ! Will try and find the 5vstby kit.

[awyatt2]

Re: Samsung PN50b550T2FXZA Big disappointment

here is the print in case I am at work on wednesday

[R1racer]

Re: Samsung PN50b550T2FXZA Big disappointment

yes there is a way to check the 3 legged components but you have to know if they are diode,fet,npn,pnp to know how to test. shop jimmy also has the repair kit unsure as to whether it would do you any good as to components if indeed it is a cold solder joint though. resolder all suspect joints and see what happens. if you need trhe print on the ps I have it in pdf form.

That would be the plan .. Will resolder and go from there . Can please send me the PDf as well . It's been so long since I did read schematics but will give it a shot

[awyatt2]

Re: Samsung PN50b550T2FXZA Big disappointment

the print is on the prior to your last its the pdf attachment broken down in sections. hope it helps you. I would start with the stby section as to resolder and don't forget to try the cap if you have a replacement if not I have one I can send you a Panasonic low esr 47uf@50v

[R1racer]

Re: Samsung PN50b550T2FXZA Big disappointment

the print is on the prior to your last its the pdf attachment broken down in sections. hope it helps you. I would start with the stby section as to resolder and don't forget to try the cap if you have a replacement if not I have one I can send you a Panasonic low esr 47uf@50v

Ok will do .i recall you mentioning that 47uf@50v is for testing only or that would be perminat. I think the one in place some where near either 100uf or volt but can't 100% recall the value

[awyatt2]

Re: Samsung PN50b550T2FXZA Big disappointment

47uf@50v is the correct value low esr cap would be permanent std would be test. you need low esr here as it may be a part of it not starting. did you find the pdf print ?

[R1racer]

Re: Samsung PN50b550T2FXZA Big disappointment

47uf@50v is the correct value low esr cap would be permanent std would be test. you need low esr here as it may be a part of it not starting. did you find the pdf print ?

Yes I saw the PDF ..thxs

If I understand you correctly the 47uf@50v is low ESR to replace the high rated OEM which might be the issue. !!

If so is it available at radioshack

[awyatt2]

Re: Samsung PN50b550T2FXZA Big disappointment

no it isn't radio shack is not low esr! its just a general purpose cap. put it in and you will be sorry in less than a week. the one there is low esr but it may or may not be bad reason I say that is the pfc has to start to start the switching supply. the power board isn't linear in design it is switch mode. pfc is power factor correction.

[awyatt2]

Re: Samsung PN50b550T2FXZA Big disappointment

when you tried the hair dryer did you heat the area where that cap was? if not try just heating that cap and see what happens.

[ReeceyBurger123]

Re: Samsung PN50b550T2FXZA Big disappointment

Pfc isnt needed to work the standby though lol