Samsung plasma wont power on pn50a550

[shelby5041]

Hi

Picked up this tv today....when plugged in u can hear a click but standby light just blinks red

Wont power on

I do get 5v standby power

Is there a common issue with this brand/ model for no power on?

Also on logic board there are 2 green leds that just blibk rapidly continuously when tv plugged in.

No blown fuses on y or z or ps

[shelby5041]

Re: Samsung plasma wont power on pn50a550

I was thinking of removing cables from boards to see if i can get to power on and isoltae issue .....but some of these models wont power on with certain boards disconnected but it cant hurt to try

[shelby5041]

Re: Samsung plasma wont power on pn50a550

I checked and all voltages coming from ps appear to be good so ps prob not issue

Vs good
Va good
Vg good
Standby good

[shelby5041]

Re: Samsung plasma wont power on pn50a550

If i unplug y board from ps tv still wont power on

If i unplug z board from ps tv will still not power on

[aaronwt6]

Re: Samsung plasma wont power on pn50a550

Main board issue. Try replacing C102 on the back. There are tons of threads about this if you just search for 'C102' on here. If the TV isn't playing the startup tone over and over, there's a good chance that the board has been damaged beyond just replacing C102 but that's a good place to start. 9x out of 10 it will remedy the issue.

[shelby5041]

Re: Samsung plasma wont power on pn50a550

Hi thanks

Tv does not power on at all....no pic...no sound...no jingle

The front samsung logo is lit up and all output voltages from ps are good but keeps clicking and wont power up

[shelby5041]

Re: Samsung plasma wont power on pn50a550

I will reseacrch the c102 issue....like u said its a start...and mine keeps cycling / making clicking sound every minute or sonbut never does turn on.....not sure if c102 is same repair as mine..

Thank you

[shelby5041]

Re: Samsung plasma wont power on pn50a550

Brief research on this model had many main board issues...either reflowing or replacing c102 fix most cycling issues

There are no main boards for sale on ebay and many people selling main board repair kits for this model....so im going to concentrate on main board

Doubt its a y or z issue

[attainteddragon]

Re: Samsung plasma wont power on pn50a550

you can confirm if it the main board by running the test patterns.

disconnect the lvds cable and jump pin 3+4 on the control board. if all other boards are good, you will have good clean test patterns showing on the screen.

[shelby5041]

Re: Samsung plasma wont power on pn50a550

Ok i will try tomorrow

I tried reflowing main in oven at 385 for 10 min....didnt fix issue

[shelby5041]

Re: Samsung plasma wont power on pn50a550

Do i disconnect power cable to main or just the lvds?

And where are pins 3-4 on logic?

[shelby5041]

Re: Samsung plasma wont power on pn50a550

Can you clarify please

[attainteddragon]

Re: Samsung plasma wont power on pn50a550

post a pic of your control board and we will point it out.

[shelby5041]

Re: Samsung plasma wont power on pn50a550

ok i will when i can....quick question....on the main board is a surface mount cap c102

its 47uf 10v "tatulum" polymer

can i just rrplace it with a typical thriugh hole alum cap and soldrr legs to pad?

[shelby5041]

Re: Samsung plasma wont power on pn50a550

and r u saying disconnrct lvds cable on logic and jump pins 1/3 whrre the rrmoved connector was?

[attainteddragon]

Re: Samsung plasma wont power on pn50a550

i believe that you can change out that tantalum with a low esr alu cap, but i will let someone else confirm that.

there are 4 prongs or holes for jumping on the control board. you will need to jump pin 3 and 4.

not jump the lvds connector pins.

[shelby5041]

Re: Samsung plasma wont power on pn50a550

ok now i understand

ill try to post pic

[shelby5041]

Re: Samsung plasma wont power on pn50a550

pic of logic board

[aaronwt6]

Re: Samsung plasma wont power on pn50a550

You can at least test the board using an aluminum capacitor. I'd recommend an equivalent surface mount for a permanent replacement but I do believe people have had decent luck either way with the repair.

[shelby5041]

Re: Samsung plasma wont power on pn50a550

i agree....will test...with alum since i have some