pn50b650s1f

[bodaciuos]

having voltage issues on my samsung plasma pn50b650s1f. at first i had no sound or picture. after a couple of replacement part. i at least have audio know. so getting to my issue is that when i plug it in audio boots up fine but with no pic. i check all the reading on power supply voltage is fine . but the no. 1 PS pn pin to control board goes from 3volt to 125 from stby to on . do i have a short maybe. has anyone ever have this issue..

[Caleb]

Re: pn50b650s1f

Check fuses on ysus first, xsus second, probably going to be buffer failure that took out your ysus. what parts did you replace?

[bodaciuos]

Re: pn50b650s1f

y s is good get vscan voltage -200 it . replaced the control board and main board.and the power supply

[bodaciuos]

Re: pn50b650s1f

i do have a buffer board and y sustain i was afraid to install it .ill try to see if that the problem. i didn't think i was.

[bodaciuos]

Re: pn50b650s1f

ok at least know i get a faint glow on the panel.. but not up completely. im still getting 126 volt on the ps on in thou. getting closer . thank for your input celeb.bro..lol

[bodaciuos]

Re: pn50b650s1f

any one know how to check ir board? to eliminate the probability. or check ardress board. i here they have a fuse on them but i dont see any..

[Caleb]

Re: pn50b650s1f

I doubt it is the ir board, What is the panel number on your tv, i can see the sticker in the picture with the xsus but cant read the fine print- I came up empty on the model# for a service manual. If your panel is primed (glows) you could still have a main board issue. you can try jumpering pins 3 and 4 on the control board with lvds unplugged and see if you get test patterns on the screen.

[bodaciuos]

Re: pn50b650s1f

thanks,, if u can find service manual. can u get it to me ? that will be great. sorry we may be in different time zone but in i WA state.

[bodaciuos]

Re: pn50b650s1f

so i found a bad fuse on the e buffer board blown at least i think that what its called ,bottom of the tv. its on f2500. it says f8r on it. any one know where i could find this fuse? or a compatible one. also i remove the plug and im hoping there in the right position. if any one can verify if the plug are on correct. thatll be great. if u notice the blue dot that will be my reference.

[bodaciuos]

Re: pn50b650s1f

I doubt it is the ir board, What is the panel number on your tv, i can see the sticker in the picture with the xsus but cant read the fine print- I came up empty on the model# for a service manual. If your panel is primed (glows) you could still have a main board issue. you can try jumpering pins 3 and 4 on the control board with lvds unplugged and see if you get test patterns on the screen.

tried to get a test pattern, no good. but by looked at the screen carefully. it has a 5 inch lighter glow on each side than the middle of the screen. if thats any help or indication of a specific problem.

[tom66]

Re: pn50b650s1f

The connections are OK compared to another model I did recently.

It's important that you DO NOT unplug/plug in that connector while the unit is running.

Not only will the fuse often blow it can also damage the plasma panel drivers which are non replaceable!

Also, you absolutely MUST have the heatsink bolted on them while running it.

[Caleb]

Re: pn50b650s1f

this is the closest thing to your tv sm I could find, attaching the quick start sheet as well for a similar model. Im not sure what the rating on that fuse is, however you should test the outbound side of that fuse against ground to see if you have a short present before replacing.

[bodaciuos]

Re: pn50b650s1f

so will this buffer board make my ps on pin to go up to 126 volt? ps on stby is 3volt which is good but when i turn on the set, it shoots up to 126 volt.

[Caleb]

Re: pn50b650s1f

are you saying your getting 126 volts on the standby circuit? 126v would be ok in parts of the power supply but certainly not on the standby circuit. You should have about 120 volts on the ac side of the bridge rectifier, if the pfc isnt working you might find that on the filter cap although it should be up in the 170v range before the supply turns on then bump up to about 350 volts or more.
It would probably be best if you note the supply voltages that are marked on your tv and compare them to the readings you have on each connector. Also make sure you are using the right setting on your multimeter (with a good battery) and the proper ground point for the section you are testing. You may be getting erroneous readings otherwise.

[bodaciuos]

Re: pn50b650s1f

yes you are correct. this is my voltages . cn108 pin 1 of 24 pins. three volt stby. when i turn on the set, it goes to 123-126 vlts. getting 5.3 volt on stby pin 5,and stays there when i turn the unit on . i believe pin 5 stby pin is supose to drop. voltage on y buffer are correct and xsus r correct ..

[Caleb]

Re: pn50b650s1f

I would try to isolate that 126v, see if it is coming from the power board or coming off sc or ss. If you have two circuits tied together it could be bad for the components on the low voltage side of things. Can we get a close up picture of that connector as well?

[bodaciuos]

Re: pn50b650s1f

hers this pic of the board and pin in which im talking about. SS, SC..??

[bodaciuos]

Re: pn50b650s1f

I would try to isolate that 126v, see if it is coming from the power board or coming off sc or ss. If you have two circuits tied together it could be bad for the components on the low voltage side of things. Can we get a close up picture of that connector as well?

so. i isolated and turn on the power supply by it self. nothing connect to it. by jumping PS ON to ground.(pin1 to pin 5) all voltages good . the only thing im not sure of is the PS-ON pin.(pin #1) doesnt give me a reading . is it suppose to ?.

[bodaciuos]

Re: pn50b650s1f

well got it to go. but im screwed.it has red vertical line left side of the screen. bummer.. well thanks for you help celeb-ro. (in case u where wondering celebro is spanish for brain).

[Caleb]

Re: pn50b650s1f

Sorry I have been working on panasonics as of late they call the ysus sc and the xsus ss. It does appear you may have a bad panel, Maybe tom will chime in with his expert opinion. It may have a slight chance of failure in that bottom buffer, especially since the fuse was blown. Those bottom boards are usually 10-15$. (edit tried looking up replacement part and came to the realization yours are bonded to the panel. you might try a little pressure on the ribbon contacts and see if it will go away.) Pson will not give a reading on the power supply, the signal is coming from the main board back to the power supply.