Sharp LC-40LE810UN question

[tibimakai]

Re: Sharp LC-40LE810UN question

My birthday was coming up and I had to get something more expensive and the only thing that I could think of it was a scope, since I have just started up the TV repair "business", I thought that eventually I will have a use for it.
I will learn it eventually, most likely with you and others help.
I will "play" with it as I gain more confidence and understanding on how to use it.
It wasn't that expensive, $315 shipped and it became a 100Mhz for that amount in two days after I have got it, so a pretty good deal, no?
I'm reading and watching this IC's data sheet and I don't really understand how it should function.
Could somebody explain it to me in a simple way? Thank you.
I'm trying to get the IC from China, just in case that I may need it.

[tom66]

Re: Sharp LC-40LE810UN question

Show us how you are probing the transformer with a picture.

[tibimakai]

Re: Sharp LC-40LE810UN question

I was thinking about that.
When I was doing it, the "sinuses" were so tiny that they almost formed a line.
Another thing that I don't understand is this triggering, there is a separate input for external triggering, I don't have to use it?
There is a pot to adjust the trigger "level"(brown horizontal line going up and down), I have to adjust that to a certain level?

[tom66]

Re: Sharp LC-40LE810UN question

I was thinking about that.
When I was doing it, the "sinuses" were so tiny that they almost formed a line.
Another thing that I don't understand is this triggering, there is a separate input for external triggering, I don't have to use it?
There is a pot to adjust the trigger "level"(brown horizontal line going up and down), I have to adjust that to a certain level?

Scope has a horizontal and vertical scale. In order to maintain synchronisation with a repetitive signal (for example, a square or sine wave) the trigger is used to start the horizontal sweep. You don't need to use the external trigger, but it can be useful if you need to trigger off a signal but view two others at the same time. I've only used it once or twice in the last few years.

You set the trigger level and the scope will trigger if the wave rises through or falls through (slope mode - defaults to rises through.)

That is an edge trigger there are more advanced ones but I'll save you for now...

[tibimakai]

Re: Sharp LC-40LE810UN question

It was set to edge when I tested.
I have to be on slope?
What other setting has to be set? 10x it's fine?

[tom66]

Re: Sharp LC-40LE810UN question

No, set it on edge. You see the diagram which looks like _|** or **|_, that is the slope edge control. Slope trigger is different, but VERY useful for plasma debugging.

[tibimakai]

Re: Sharp LC-40LE810UN question

Finally I have received the 3BS3LJ ICs.
I had a half an hour to replace it and to my surprise I have 5V STBY(pin #11) and 12V at the output cap at the secondary(C7961A=5.55V/C7962A=12V).
I haven't had much time to measure much, but it seems that there is no PS_ON voltage.
Voltages at the IC:
#1= 0.903V
#2= 3V
#3= 0.13V
#4= 0.06V
#5= 130V(HV)
#6= 0V(NC)
#7= 15.4V(VCC)
#8= 0V(GND)
I guess I should try hooking up the bulbs and test the power supply separately.
Tomorrow I will go through all the suggestions and I will let you know where I'm standing.

[tibimakai]

Re: Sharp LC-40LE810UN question

Today I'm measuring again my voltages and they are all gone. I guess the IC it's bad again.
Vcc it's like 12.2V, HV 110.9V, everything dropped down from yesterday.
I'm measuring with the scope the output of the traf and I'm getting sinus waves.
I really need help with this TV.
I still have another IC if it's needed.
I wanted to check the 18V drop at power up, but it seems like it was to late, because all the voltages were different from yesterday.

[tibimakai]

Re: Sharp LC-40LE810UN question

I ended up replacing the IC and now I have again the 13.7V(not 12V as I said before) and 5,5V, not sure what happened.
I'm attaching some pictures with the TV and the scope measurement.
One picture is without the IC, for budm to see the traces. I hope it's good enough, it's just a phone picture.

[tibimakai]

Re: Sharp LC-40LE810UN question

So, should I buy the board?
I'm kind of scared to apply 18V to the IC. If I screw up this one to, I will have to wait another month to get new ICs.

[tom66]

Re: Sharp LC-40LE810UN question

You have supply voltages now? Does ON/OFF do anything when you press the power button?

[tibimakai]

Re: Sharp LC-40LE810UN question

I have the 5V STBY and the 13.2V(13.7), but still nothing else happens. No LEDs turning on or anything.
I can't detect the PS_ON either.
I begin to suspect the mainboard too. I'm thinking of trying to feed 3.3V from my power supply, to see if anything happens.
The wave looks good(just to see if I have measured correctly)?
The voltage doesn't rise to 18V at the IC as it supposed to.

[tom66]

Re: Sharp LC-40LE810UN question

Well, as long as you have standby voltages, for now, the PSU is OK. Time to look at the main board. Maybe a surge killed both.

[tibimakai]

Re: Sharp LC-40LE810UN question

Next step I have to take pictures with the mainboard, right?

[tom66]

Re: Sharp LC-40LE810UN question

Yes.

[budm]

Re: Sharp LC-40LE810UN question

So you do get voltages on those 16V caps in post 43 now?
By the way, is this the scope you bought?
http://www.youtube.com/watch?feature...v=BWZXGzAVkD8#!

[tom66]

Re: Sharp LC-40LE810UN question

So you do get voltages on those 16V caps in post 43 now?
By the way, is this the scope you bought?
http://www.youtube.com/watch?feature...v=BWZXGzAVkD8#!

I think he's got the DS1052E a 50 MHz scope, modded to 100 MHz. I can highly recommend the DS1102E myself as I have one.

[tibimakai]

Re: Sharp LC-40LE810UN question

Yes, I have 5.55V and 13.7V.
Yes I have the little one in the video, Rigol 1052 which became a 100MHZ scope with a mod. I picked it up from Rigol for $315 shipped. They had a bit of questioner and I have got some discount with that also.
Hardware wise is the same as Tom's 1102 though. The difference is all in the software.
http://www.youtube.com/watch?v=AUwbtG6z6pI
http://www.youtube.com/watch?v=LnhXfVYWYXE

[tom66]

Re: Sharp LC-40LE810UN question

My 1102E cost a little bit more, but only because I'm a scardy-cat and don't want to brick it by doing the upgrade wrong.

[tibimakai]

Re: Sharp LC-40LE810UN question

I can say now, that I have a 1102E
The fan noise bothers you?
I don't even hear it because I have a 20" fan and a small Tornado type fan running all the time.
When the warranty it's over, then I will replace the fan with a quite one.