Sharp Aquos LC-46D64U stand by with new boards!

[cashkennedy]

Re: Sharp Aquos LC-46D64U stand by with new boards!

The small AC input board that you attached a picture of 3 messages ago, does not convert the power to DC (I dont see a bridge rectifier on that board), so it must feed the power supply with AC power. Thus you could set your multimeter to 750v ~ (AC is symbolized by ~), and see what voltage the 2 metal pins running to the socket on the power supply board are getting (the socket is marked ACI) , you can position red on 1 pin, black on the other, order isnt very important. Be carefull not to bridge the 2 wires/ pins or touch either, as there will be a huge spark / destroy stuff, blow your breaker if you connect the white to black wire ...

BTW all the board should be connected, and the tv should be plugged in. You can take 1 reading with the TV off, and 1 with the TV on, although it shouldnt change.

[cashkennedy]

Re: Sharp Aquos LC-46D64U stand by with new boards!

After you test that, (its extremely unlikely theres any problem with that small AC input board) you can set your multimeter to DC voltages (200v =) the DC setting looks like = but with dashes bellow the upper line. You then can put the black leed on a peice of metal / or screw that holds one of the boards in place, then connect the red lead to any of the pins around the board that had clear markings like 12v, 15v, or so on. You want to do this iwth the boards all connected properly, and the tv on. Because the cable will be connected you will probably have to jam the multimeter probe into the back of the connector and fiddle around till you get a reading / make contact.

[cashkennedy]

Re: Sharp Aquos LC-46D64U stand by with new boards!

BTW I see you marked regions of the multimeter :

A is the AC voltage section (~) , and B is the DC voltage section (=) of your multimeter. You want to always be on a higher setting then what your testing. So if testign the 60v (pnl60v) then set it to 200v.

Your ac input board has 3 positions in the connector that goes to the power supply board. But if you look closely at both pics, the middle pin has no wire ran to it (so the middle pin is doing nothing). This is because it was probably for ground, and ground is run through the metal case of the TV instead of through the wire. The L wire / black wire appears to be the AC hot, and the N wire / white wire is the neutral.

BTW earlier you said something about the LED's in the TV, im not sure on this model, but based on the fact that you have 4 inverter boards and 60v running to the inverters you most likely have CCFL's not LED's. The board that has 2 ribbons running to the top of the panel is a tcon, those ribbons send the data to each pixel on the screen whether to be on / or off .

[multimeter]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Still, wouldn't the first thing to check (after checking the power cord from the wall outlet, which I've done already - checked out fine at 120volts AC), would be the DC voltage coming out of the input board and to the power supply board?

If so, what would that voltage be, and what would I set my meter to to test for it (see attachment "meter.jpg")? What pins should I test? I know one is hot, and one is ground (but not which is which), and I also don't know what the third is.

this board is a "pre" powersupply,what goes in should 120v,what comes out will be 120v,this board most likely provides a lot of filtering before the voltage hits the main psu board,giving it less stress,it dosent convert ac to dc,there isnt a bridge!

[eTanium]

Re: Sharp Aquos LC-46D64U stand by with new boards!

After you test that, (its extremely unlikely theres any problem with that small AC input board) you can set your multimeter to DC voltages (200v =) the DC setting looks like = but with dashes bellow the upper line. You then can put the black leed on a peice of metal / or screw that holds one of the boards in place, then connect the red lead to any of the pins around the board that had clear markings like 12v, 15v, or so on. You want to do this iwth the boards all connected properly, and the tv on. Because the cable will be connected you will probably have to jam the multimeter probe into the back of the connector and fiddle around till you get a reading / make contact.

Thank you for all that helpful information! Just to clarify, so that I don't blow myself up, the TV should be plugged in, but also have the power on?

Now there is an issue here:

A) I can only get the TV to be in stand by with the power LED indicator staying solid green, at which time I can hear the Main Board's processor cycling current. I do this by holding the channel down button, and the volume up button at the same time while I plug the TV into the wall.

B) The TV will be in stand by mode and flashing the error codes when I plug it in, and without any type of rest. At this point, I don't think the voltage is running correctly, if any at all, through most of the boards. When it is in this mode, it makes the an on/off sound as soon as it is plugged in. The power supply seems to get power, but immediately toggles something off, noted by the "click/clock" sound.

Which is the best scenario for checking the voltage at this time?

[multimeter]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Thank you for all that helpful information! Just to clarify, so that I don't blow myself up, the TV should be plugged in, but also have the power on?

Now there is an issue here:

A) I can only get the TV to be in stand by with the power LED indicator staying solid green, at which time I can hear the Main Board's processor cycling current. I do this by holding the channel down button, and the volume up button at the same time while I plug the TV into the wall.

B) The TV will be in stand by mode and flashing the error codes when I plug it in, and without any type of rest. At this point, I don't think the voltage is running correctly, if any at all, through most of the boards. When it is in this mode, it makes the an on/off sound as soon as it is plugged in. The power supply seems to get power, but immediately toggles something off, noted by the "click/clock" sound.

Which is the best scenario for checking the voltage at this time?

is the sound you describe a ticking noise?,if it is i would be first checking the start up capacitor,most prob a 22uf 50v etc,then the output capacitors for high esr,they dont need to look failed to be failed.and the the optoisolators ,if there is no feeback voltage ,the supply will shut down

[cashkennedy]

Re: Sharp Aquos LC-46D64U stand by with new boards!

The AC power from the input board to the power supply will always be on. So you can measure it anytime the TV is plugged in.

The DC voltages should be partially on when the TV is off / standby, and all should be working when the TV is on. The 60v is one of the ones that will only be on while the TV is fully on. You can figure out how "on" the tv is by seeing which all are on when the TV is in both of the states you mentioned.

LOL multimeter, your posts are probably intelligent but are yoing to be way over this guys head... are the optoisolators the 4 pins parts that bridge the Primary to secondary, I dont even know myself. I think the noise he is refering to is the relay clicking also. It only occurs twice when he plugs the tv in and doesnt continue to click i believe?

[cashkennedy]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Im working on a sharp power supply myself, so am curious how to test the optoisolators. Assuming they are the "optocouplers" that connect the primary to secondary. How do you test them? I tested all the ones on my board with the diode setting and the with the red lead on the circled black pin i would get a diode reading only to the pin on the same side. But on 1 out of the 5 which are all the same part number i get a diode reading much lower and its the same in either direction i connect the leads. so while most are 1.4v in 1 direction, this one optocoupler is .9 in both directions...

[eTanium]

Re: Sharp Aquos LC-46D64U stand by with new boards!

MultiMeter, the noise is more of a "tick - tock" within a second. It happens when I plug the TV in, unless I am holding down the rest buttons (channel/volume). It does sound that the board is shutting itself off when I hear this. Yet, this is a new board, and it was happening with both the old and the new board. I took a look at the larger capacitors, and none seem bulged on either board.


Cashkennedy - so, I think i am going to try to get the TV set to be in option B that I described earlier, where the Power LED in front is solid and steady, at which point I can hear electricity running through the main board.

So, if everything on the power supply board is running correctly, the voltage I measure on the output connectors A-F should be at the voltages stated next to them on the Power Supply Board, no?

Lets take E (top left corner of the "combined.jpg" attachment) for example (inverter board #1):
- There are three pins here.
1) UR60V - which should produce 60 volts?
2) SGND3 - which should be a ground - no measurement needed?
3) UR12V - which should produce 60 volts?

So, if I were to measure this, I would set my meter as you described earlier, and then use my black probe to touch anywhere on the metal case (ground), and touch each of the three pins with the red probe so as to measure their voltages? I should expect the meter to read what the board has labeled for each pin? 60Volts being at full operating voltage?

Is there any issue with touching the SGND3 pin with the hot probe while having the other one grounded?

Also, if I don't get the reading labeled on the board, is it power supply board being defective, or the card it is connected to (in this case inverter board #1)?



Again, I apologize for all the questions, but this is new ground, and I am always a cautious person. Is there anyway I can ground myself? I am working in my living room with a carpet floor.

[cashkennedy]

Re: Sharp Aquos LC-46D64U stand by with new boards!

In conector E the (and for F since its the same thing)

ur60v should be 60v DC
sgrnd should be 0v (ground) its safe to test with red probe, essentially its the same thing as the metal case)
ur12v should be 12v DC

Both of those will only be on (show voltages) while the TV is on. So if theyre showing 0 volts more likely the tv is just not fully on. If you have 4 hands you can try measuring them for the 1 second while it clicks on and off.


the only voltage i can guarantee you is on (so that you can make sure your meter is working and your testing corretly) is the bu5v in the B connector . it should be 5v DC.

In regards to safety, just be carefull not to touch anything metal, and deffinetly dont touch the heatsinks on the power supply while the unit is on / plugged in. I think grounding yourself is the opposite of what youd want to do to not get shocked. The safest thing you can do is plug the TV into a GFCI outlet (such as in your bathroom), but i wouldnt go to much trouble to worry about that, easier to just be slow and carefull not to touch anything.

[multimeter]

Re: Sharp Aquos LC-46D64U stand by with new boards!

MultiMeter, the noise is more of a "tick - tock" within a second. It happens when I plug the TV in, unless I am holding down the rest buttons (channel/volume). It does sound that the board is shutting itself off when I hear this. Yet, this is a new board, and it was happening with both the old and the new board. I took a look at the larger capacitors, and none seem bulged on either board.


Cashkennedy - so, I think i am going to try to get the TV set to be in option B that I described earlier, where the Power LED in front is solid and steady, at which point I can hear electricity running through the main board.

So, if everything on the power supply board is running correctly, the voltage I measure on the output connectors A-F should be at the voltages stated next to them on the Power Supply Board, no?

Lets take E (top left corner of the "combined.jpg" attachment) for example (inverter board #1):
- There are three pins here.
1) UR60V - which should produce 60 volts?
2) SGND3 - which should be a ground - no measurement needed?
3) UR12V - which should produce 60 volts?

So, if I were to measure this, I would set my meter as you described earlier, and then use my black probe to touch anywhere on the metal case (ground), and touch each of the three pins with the red probe so as to measure their voltages? I should expect the meter to read what the board has labeled for each pin? 60Volts being at full operating voltage?

Is there any issue with touching the SGND3 pin with the hot probe while having the other one grounded?

Also, if I don't get the reading labeled on the board, is it power supply board being defective, or the card it is connected to (in this case inverter board #1)?



Again, I apologize for all the questions, but this is new ground, and I am always a cautious person. Is there anyway I can ground myself? I am working in my living room with a carpet floor.

disconnect the inverter board cables,does the ticking noise stop?,"Is there any issue with touching the SGND3 pin with the hot probe while having the other one grounded?",if you have your black probe on the gnd and red probe on the voltage outputs no,it will be fine,

[cashkennedy]

Re: Sharp Aquos LC-46D64U stand by with new boards!

disconnect the inverter board cables,does the ticking noise stop?,"Is there any issue with touching the SGND3 pin with the hot probe while having the other one grounded?",if you have your black probe on the gnd and red probe on the voltage outputs no,it will be fine,

The inverter board cables are E and F , in case you want to try his suggestion.

[eTanium]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Yep, I am aware that E and F are the same, and that they are for the inverter boards, but thanks, it's always good to clarify (especially since most of my other jargon has been off, haha), thanks.

So, if there is a bad inverter board, it could be causing the switch (thanks I had been trying to remember that correct terminology) to open and close - producing the noise? If they are removed, the noise should then stop, and the TV stay on?

Let me try that.

BRB

[eTanium]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Ok, well, I disconnected the inverter boards, and got the same tick/tock.

I went ahead and measured the voltage coming from the input board to the power supply board and only got 65volts! Shouldn't that be at 120volts?

[cashkennedy]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Disconecting those boards will most likely not change the tv's on / off problems. But if the ticking is comming from a bad inverter transformer then it might stop the ticking. (He just wants to try to isolate where the ticking is comming from)

But without those boards disconnected the TV will shut off 100% of the time, usually with a error code (possibly 1 green light every second).

[multimeter]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Ok, well, I disconnected the inverter boards, and got the same tick/tock.

I went ahead and measured the voltage coming from the input board to the power supply board and only got 65volts! Shouldn't that be at 120volts?

give me a sec ,il look at your input board again,you should have 120v coming out of the input board going into your main power supply board

[cashkennedy]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Did you have the multimeter in the A area (ac voltage ~) and at 700v? and you put the red probe on N and the black problem on L (touching them where they enter the power supply board)?

If you did it exactly that way and only got 65v then this would be alarming yes.

[eTanium]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Also, I just checked the inverter board readings, and they checked out at 60.5V and 11.9v respectfully.

I tried to test the connect for the main board, and the terminal board (connection C & B), but I go no readings. I am not able to get to the pins with connector cables attached. If I remove these cables, will I still get readings from the pins? If not, how do I measure the pins when cables are connected? The probes are just too big to be jammed in there!

Also, thanks again for the help - using this meter and getting conclusive results is making me feel Boss!

[multimeter]

Re: Sharp Aquos LC-46D64U stand by with new boards!

ok,when you read the output voltage from the input board,you had your meter on ac yes,i hope so!,if you did,ok,on the input board there are 2 lots of 3 blue capacitors,stick your meter on diode setting ,and black and red probe on each one of the capacitor legs,its not a definate go no go,beacause they really need to be insulation tested for accurate results,but it mite give a little indication if they are shorted,you should get a reading on your meter of "0L" OR "1"

[eTanium]

Re: Sharp Aquos LC-46D64U stand by with new boards!

Did you have the multimeter in the A area (ac voltage ~) and at 700v? and you put the red probe on N and the black problem on L (touching them where they enter the power supply board)?

If you did it exactly that way and only got 65v then this would be alarming yes.

Nope, I was one step off. I had the negative (black) probe touching the metal of the TV as a ground.

I just did as you stated, and got 120volts! Ok, onto the next issue.


Also, to answer your question about EXACTLY where the switch noise is coming from, the primary portion (right) of the power supply board. I believe it is to the far right of the primary portion of the power board, and is covered by a vertical section of metal (encased).