Samsung PN60F5500, making me question my sanity

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

Did you try turning TV on with all cables connected properly and the 3/4 service pin jumpered? (instead of removing power to the mainboard).

If so, what was LED blink like?

I will try that next.

[dick_barton]

Re: Samsung PN60F5500, making me question my sanity

I was testing in DIODE check, but when just checked with OHMS I found that both read 20.0 ohms either way between adjacent (side by side) pins. The number on both parts is: K15A50D. See picture attached. Thanks for your help!

The only way to tell without the schematic would be to lift out the component and then test.

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

Did you try turning TV on with all cables connected properly and the 3/4 service pin jumpered? (instead of removing power to the mainboard).

If so, what was LED blink like?

The LED blinks every 4 seconds with this and I think it's the same frequency as earlier (I think my 1-2 second estimate was off).

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

The only way to tell without the schematic would be to lift out the component and then test.

Okay, Dick Barton of Wales, thank you for your input, would you suggest doing so?

[dick_barton]

Re: Samsung PN60F5500, making me question my sanity

If there's a low resistance across any components ie diodes, mosfets then it is best to remove them from the board to test them. The low resistance could be because they are connected to a transformer or they are in parallel with a low value resistor so you cannot always tell if the part is faulty when still in circuit.

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

If there's a low resistance across any components ie diodes, mosfets then it is best to remove them from the board to test them. The low resistance could be because they are connected to a transformer or they are in parallel with a low value resistor so you cannot always tell if the part is faulty when still in circuit.

Sure enough, when desoldered, they read open between those pins now instead of 20 ohms. Darn, was hoping that was the issue. Any ideas now?

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

Any other ideas from anyone else?

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

Anyone? I'm thinking to try the main board, but some here have said if the LED is blinking on here then that rules it out, but...?

[mtnickel]

Re: Samsung PN60F5500, making me question my sanity

If you were wrong on your blinking from before then the LED may be showing a fault.
If it is in fact a quick blink every 4-6 seconds, this indicates that it's detected a fault and turns off the voltages (as you experience them going down).
If that is the case, I would try the X/Y mainboard next. I had the same blink fault (every 5-6 seconds) and the mainboard solved it. Again, check for some sellers and see who allows returns. Sometimes helps to email ahead and ask and say you're swapping boards and wonder if they allow a restocking fee/etc if you cover shipping.

I'm new at fixing these things and just an amateur, but if the buffers are not shorted and the mainboard was powering on and is showing some reading (the LED blinking meaning it's ran some sort of booting routine) then I would try that next.

Good luck.

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

If you were wrong on your blinking from before then the LED may be showing a fault.
If it is in fact a quick blink every 4-6 seconds, this indicates that it's detected a fault and turns off the voltages (as you experience them going down).
If that is the case, I would try the X/Y mainboard next. I had the same blink fault (every 5-6 seconds) and the mainboard solved it. Again, check for some sellers and see who allows returns. Sometimes helps to email ahead and ask and say you're swapping boards and wonder if they allow a restocking fee/etc if you cover shipping.

I'm new at fixing these things and just an amateur, but if the buffers are not shorted and the mainboard was powering on and is showing some reading (the LED blinking meaning it's ran some sort of booting routine) then I would try that next.

Good luck.

Thank you for your reply. Can you clarify what board you are saying? You said, "I would try the X/Y mainboard next. I had the same blink fault (every 5-6 seconds) and the mainboard solved it."

So, I'm confused if you meant the X or Y board or the MAIN board?

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

Also, I want to post that the blink frequency is in fact every 3 seconds; I rechecked it and wanted to be very accurate in my timing. Does that change anything?

[freakaftr8]

Re: Samsung PN60F5500, making me question my sanity

That's just simply means in optoisolator is resetting most likely. Samsung's do not inhibit blink codes. Sounds like a direct short somewhere

[mmartell]

Re: Samsung PN60F5500, making me question my sanity

He's talking about the blinking led on the logic board.

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

He's talking about the blinking led on the logic board.

Indeed, yes, I was talking about the blinking LED on the logic portion of the main board.

[freakaftr8]

Re: Samsung PN60F5500, making me question my sanity

I got it that one slip by me. Try heating up the Y sustain board. Especially around the blue film capacitors on the Y sustain. You can use a hair dryer for this. Do this with the TV powered off. Heat up around these capacitors and then power up. Had a 60 and version doing the same shutdown because High Resistance ESR causing the logic on the sustain board to shut down due to the voltages not coming up in time. These newer TVs seem to have even a smaller window ramp up then the older ones did

[mtnickel]

Re: Samsung PN60F5500, making me question my sanity

Thank you for your reply. Can you clarify what board you are saying? You said, "I would try the X/Y mainboard next. I had the same blink fault (every 5-6 seconds) and the mainboard solved it."

So, I'm confused if you meant the X or Y board or the MAIN board?

Sorry. On this TV (like mine) the X and Y sustain function are actually on the same board. Maybe "mainboard" was wrong term to use since people associate that with the input board or control board. Lets call it the X/Y sustain board then.
But try the advice of freakaftr8 first. Again, I'm just an amateur who's only fixed 2-3 TV's so far.

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

I got it that one slip by me. Try heating up the Y sustain board. Especially around the blue film capacitors on the Y sustain. You can use a hair dryer for this. Do this with the TV powered off. Heat up around these capacitors and then power up. Had a 60 and version doing the same shutdown because High Resistance ESR causing the logic on the sustain board to shut down due to the voltages not coming up in time. These newer TVs seem to have even a smaller window ramp up then the older ones did

I tried that, but no change. Thanks for the input. Any other ideas?

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

If I want to order some boards to just try a shotgun approach on this, what would you guys suggest first? And it seems like I could do something more to test the boards...but I guess not?

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

Anyone have the service manual for this? Aren't Samsung S/M's usually just block diagrams/flow charts? Maybe it would help?

[Truncatedhose]

Re: Samsung PN60F5500, making me question my sanity

I guess that's a no?