Stumped on Samsung PN60E530A3F

[MagicSmoke]

Re: Stumped on Samsung PN60E530A3F

Reading the datasheet I see it indicates the cap for the blanking time Cbk is restricted to less than 0.65uf.

The cap in the board is a 10uf, could this be the problem? Was also wondering about the resistor on CS pin.

Will check voltage @ power on and let you know.

[drussell]

Re: Stumped on Samsung PN60E530A3F

Reading the datasheet I see it indicates the cap for the blanking time Cbk is restricted to less than 0.65uf.

The cap in the board is a 10uf, could this be the problem? Was also wondering about the resistor on CS pin.

No, no... That's a different cap. The one that is on the blanking time is a .1uf surface mount on the back of the board. I even tried removing that so there was nothing connected to that pin; had no effect.

The 10uF is the power supply capacitor on the VCC for the chip.

The CS resistor isn't in play yet when the chip is starting up since it's not doing any current yet there is no voltage across it since the chip hasn't started yet. It's the < 1 ohm one standing up off the board below the two blue snubber capacitors in parallel to the right of the chip.

[MagicSmoke]

Re: Stumped on Samsung PN60E530A3F

Well Finally some success, changed the 106 cap @C5162 to a 10uf 50v electrolytic. Did not have a 10uf in lower volts. This is on the board that I changed the 3BR0665J.Pressed power and it came on first try. No freezing of anything.

Highest volts on Vcc read at start was 15.9v then leveled to 15.3v. When turned off it jumps to 16.1v briefly, then drops when VS bleeds off.

I am about to do the same thing to another Y board and see if it works on that one too. I have not changed the chip on this one so hopefully it will work also.

EDIT.... Just when I thought all was good..... let it run 15 min, turned it off and no joy. 18.6v was highest recorded during start with no picture. But froze opto again and it turned on with pic. When sprayed it caused transformer to squeal briefly.

Do you think dropping the caps uf would help or is the opto weak. it tests ok on my meter.


More weirdness in operation. It's been on with picture for about 30 min after freezing the opto.......

When I freeze the opto set will turn on w/picture.

If Vcc volts are above 9.5v residual after turning off it will come on again w/pic. Verified 5 times. If residual volts on Vcc go below 9.5v then opto needs refreezing to start with picture.

[drussell]

Re: Stumped on Samsung PN60E530A3F

But froze opto again and it turned on with pic. When sprayed it caused transformer to squeal briefly.

Interesting, certainly seems like the optocoupler is involved with your problem somehow. I can't believe whole this circuit is so flakey!

Do you think dropping the caps uf would help or is the opto weak. it tests ok on my meter.

Unless the cap is very leaky it should be fine. The charge current is only 0.9ma before it starts up but it's only a 10uF cap.

The optocoupler could be leaky too I suppose but that is a strange failure mode.

More weirdness in operation. It's been on with picture for about 30 min after freezing the opto.......

When I freeze the opto set will turn on w/picture.

If Vcc volts are above 9.5v residual after turning off it will come on again w/pic. Verified 5 times. If residual volts on Vcc go below 9.5v then opto needs refreezing to start with picture.

I'm going to try playing with this one some more later this evening but that's certainly very strange behavior from the optocoupler.

Like I said, it certainly seems to be involved in your case, though.... Hmmm...

[MagicSmoke]

Re: Stumped on Samsung PN60E530A3F

This is on the board that I changed the 3BR0665J.

It seems that was incorrect, I have 2 of these and got confused.

On the second board that I did actually change that chip and the film cap to an electrolytic, seems to have fixed it so far. It's been on about 30min.

It powers up w pic (so far) everytime after running. Let residual Vcc go to 0v and still comes on. Still testing it so we'll see. Thanks drussell for the help getting it this far.

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

Ok, new to this. Please kindly advise if I am doing something wrong.
Question first. What are the odds of 3 tvs have bad boards with the same problem?
No picture only sound. logic boards blinks 5 second.
I purchased a Samsung pn60e530a3f the picture was not supposed to display. The set will always play sound. I set it up in my garage. For the first few days it would work correctly every other try. It would seem to work normal once it actually turned on. You could turn it off and on without a problem. After a few days the display would no longer come on at all. The logic board has the 5 second blink. I disconnect the ribbon to the y main and the logic board is happy again. I have 3 sets of y-boards, x boards, and power supplies. Two sets are out a cracked screens. I have two input boards and two logic boards. I have changed all the boards and cables at once and still no love from the tv. I have not tried jumping wires or shoving my tester into this tv yet. I have bad luck with frying electrical components once I go that far.

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

Freezer test on the Ymain and buffers did not yield any results

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

[QUOTE=MagicSmoke;522949]Well Finally some success, changed the 106 cap @C5162 to a 10uf 50v electrolytic. Did not have a 10uf in lower volts.

Could I get a picture of this?

[drussell]

Re: Stumped on Samsung PN60E530A3F

What are the odds of 3 tvs have bad boards with the same problem?

Yeah, with this series of TV there's probably a pretty good chance that all of them are faulty

For the first few days it would work correctly every other try. It would seem to work normal once it actually turned on. You could turn it off and on without a problem. After a few days the display would no longer come on at all.

Have you tried some freeze spray directly on the IC as described earlier in this thread or did you only try putting the whole Y in the freezer?

Two sets are out a cracked screens.

Boards out of cracked-screen plasmas can be problematic if a power-up attempt was made after the screen cracked. Boards handling power or interfacting with the panel itself, that is... A main board or some separate-style logic boards should always be OK, though.

Could I get a picture of this?

The cap is the little blue one with the jumper wire going to it in the picture attached to post #31 in this thread. If you use an electrolytic, the + side needs to go to the right side (which is the + VCC for the IC) as viewed from the top in that photo. The other side is grounded so it is easy to verify with your multimeter that you are connecting the + to the IC's VCC pin and the - side to ground (same potential as the chassis screw holes, etc.)

I have one of these around here somewhere still I should pull out again...

P.S. Don't bother messing with the buffer boards, it's almost certainly this same Y-Main problem by the sound of your description of the problem...

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

I tried the freezer test. I tried jumping the cap in pic #31. My vs and va voltages are good at the power board test points with the ribbon to the y board removed. When I first installed the boards from the second tv I did not hook up the plasma panel. I had the same 5 second blink from the logic board. I looked into a y main repair kit. I do not think I am that good at soldering.

[drussell]

Re: Stumped on Samsung PN60E530A3F

I tried jumping the cap in pic #31.

"Jumping" the cap will make the situation worse. If the capacitor is involved at all it seems that it is because it becomes leaky and doesn't allow the voltage to rise quickly enough. You need to remove the ceramic cap and put in a new one that doesn't leak for it to have any effect. Adding capacitance will just make the VCC even slower to come up.

My vs and va voltages are good at the power board test points with the ribbon to the y board removed.

The Vs and Va voltages are not involved in this problem. The only reason they drop is that the logic board shuts off the high voltage supplies when it senses a problem. (In this case the problem being the Vscan supply not coming up quickly enough.)

When I first installed the boards from the second tv I did not hook up the plasma panel. I had the same 5 second blink from the logic board. I looked into a y main repair kit. I do not think I am that good at soldering.

It is quite likely it will sense a problem if the panel is not hooked up but be sure to test the boards that came from cracked-screen TVs thoroughly for shorts on the FETs, IGBTs, etc. before you try hooking them to a panel, though a cracked screen is somewhat more likely to blast the buffers than the Y-Main itself.

A typical Y-Main repair kit will include power components like the FETs/IGBTs which, again, aren't involved in this particular problem if this problem is indeed what you are seeing.

You will see a lack of Vscan and Ve and the Vs and Va will dropout once the fault is set but will come up initially. If it is this same fault, it will be the Vscan supply. It took me a while to realise it was not the Ve (which also doesn't come up but is not where the problem lies) but rather the Vscan supply.

Watch the voltage on that capacitor. The chip needs to see close to 18 volts to start up. If it is not getting there then that is quite likely the same problem.

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

Since they wanted all their TVs up and working for football, I did a temporary hack job yesteday to make these sets able turn on until the ICE3BR0665J chips arrive.

I made a voltage divider using about 120K ohm (needs to be at least a 0.5 W) from the Vs to a piece of wire and also to about 13K to ground (0.25 W is fine), heat shrinked it up and connected the wire to the VCC of the PWM controller. Check to be sure you don't get more than the 25V maximum rating of the controller chip before you connect it to the chip's VCC at the capacitor, the jumper or the VCC pin itself. It measured just over 20V here but will depend on your Vs voltage and the exact resistors used.

This charges up the VCC capacitor to above the 18v turn-on threshold regardless of the flakey precharge supply in the chip and makes the TVs come on first try. Not the best permanent solution but really shouldn't matter either.

At least it works.

I am getting confused. You attached a picture to this post. That is part "106 cap @C5162" right. This is the one Magicsmoke "changed the 106 cap @C5162 to a 10uf 50v electrolytic" right?

[drussell]

Re: Stumped on Samsung PN60E530A3F

I am getting confused. You attached a picture to this post. That is part "106 cap @C5162" right. This is the one Magicsmoke "changed the 106 cap @C5162 to a 10uf 50v electrolytic" right?

Correct.

Stick your multimeter probes on the two legs of that little blue capacitor at position C5162 and try to turn the TV on. If the voltage doesn't jump to at least 18 volts, the -Vscan PWM controller IC will not start and there will be no -Vscan voltage. The logic board will sense this lack of -Vscan voltage condition and shut down the high voltge supplies and you will get no picture.

The problem may potentially be any combination of the capacitor, the chip or something else related to that circuit.

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

Am I supposed to have "BOTH" probes on the legs or did you mean test each leg during power up?

I tested each leg. The left leg jump from 0 to 18 during start up. It hen began to drop. I quickly checked the other leg and 0. Check the first leg again and it was still dropping.

I then tested both legs. I could not comfortably test while turning on the tv. I turned on the tv and quickly tested the legs at the same time. 15.3 and then it started dropping.

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

I will check back tomorrow.

[drussell]

Re: Stumped on Samsung PN60E530A3F

Am I supposed to have "BOTH" probes on the legs or did you mean test each leg during power up?

It doesn't matter if you use the left leg or chassis ground for the second probe as the left leg is at chassis ground potential. You're essentially just measuring the voltage on the right-hand pin anyway.

I tested each leg. The left leg jump from 0 to 18 during start up. It hen began to drop. I quickly checked the other leg and 0. Check the first leg again and it was still dropping.

You must mean the right leg as viewed from the back went to 18 volts. The left leg is at chassis ground potential. That is strange, though, as on the ones here I never get to 18 volts on the ones with faults. Without a fast-reading multimeter or a storage scope with data logging it may be difficult to see exactly what is going on with that supply voltage.

Of course, you may also have some completely different problem.

Does your -Vscan supply ever come up at all? It should be about -200 volts but it might be isolated, you may have to measure it across the capacitor labelled as the -Vscan test point rather than using one probe to chassis ground. You might try alligator clip leads if you don't have some sort of micro-hooks to attach to your multimeter probes.

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

Yes, vscan comes up within range. I will test again later today.

[drussell]

Re: Stumped on Samsung PN60E530A3F

Yes, vscan comes up within range. I will test again later today.

You are probing the wrong capacitor. The one in your photo is C5160. To check the VCC supply to the controller chip you want the one between the controller chip and the optocoupler, C5162.

If your -Vscan is coming up full, though, you are hunting a different problem than the -Vscan supply issue we were having on these sets.

Did you thoroughly check the Y-Main for shorted FETs/IGBTs, diodes, etc? It is possible something has gone south on you there since the time when the TV would work after multiple power-up attempts. THAT issue still sure sounds like the -Vscan supply problem.

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

I will recheck later today to see if I probed the wrong one or if I drew the picture wrong.

[johns1mj]

Re: Stumped on Samsung PN60E530A3F

ok update. Multiple bad boards. For fun I changed two capacitors that looked bulged. One tested fine when it was removed. The other was out of range for my meter to test. I installed two new capacitors. I installed the board with the same result. All va, vs,vscan and ve all checked good on startup. Just for fun I swapped y buffer boards. tv fired right up. So I have 2 bad y mains and at least one bad buffer.