Sharp Aquos 70" LED LC-70LE632U does not power on

[Biffm17]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

No flashing lights errors of any kind and no standby light. I was not too sure which pins were standby which was why I was asking. They are numbered and was looking at them but their pitch are very close and don't want to short anything out and make it any worse. When I have the set plugged in and back off I can hear a very slight faint something like a human or possibly a buzz for about a second then stop the start back up then stop etc... But it is almost inaudible and never really had my he'd behind it with the back panel off of it till now. The service guide would be very helpfull if i had the diagnostic lights but cant get this to power up. I work on hi voltage stuff every day but we usually just replace boards and not do comopnent work due to reliability of infield servicing repairs and for cost reasons as well as each techs skill levels are different. Some older appliances have boards that we can pull out for the customers and send out to be rebuilt and then put in. I am confident in my component servicing ability and if economically reasonable.

[Biffm17]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

In post 1 page 1 theres a link to the service manual im not sure if you have downloaded this yet but it will have the trouble shooting pages in it,

I had already downloaded the service manual previously to joining the site, thanks.

[freakaftr8]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

Are you getting any flashing error code on the inverted v logo?

[budm]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

https://www.badcaps.net/forum/showpo...7&postcount=22

So are you getting the STBY Voltage.

[vinceroger69]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

What are the voltages I should be looking for and where to measure them? I have the same issue with no stand by light and the set will not turn on. It just stopped while watching it and did this a few times at random the months b4. I do have 120 VAC after the fuse and was seeing around 15 vac on a few caps. I really don't want to buy a board if I can find the culprit on the board! Thank you.

In post 1 page 1 theres a link to the service manual im not sure if you have downloaded this yet but it will have the trouble shooting pages in it,

[Biffm17]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

What are the voltages I should be looking for and where to measure them? I have the same issue with no stand by light and the set will not turn on. It just stopped while watching it and did this a few times at random the months b4. I do have 120 VAC after the fuse and was seeing around 15 vac on a few caps. I really don't want to buy a board if I can find the culprit on the board! Thank you.

[Biffm17]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

Hi there, new member here with the same issue. Looking to resolve the issue. Sears appliance tech here but not a TV tech. I appreciate the help and if I may be of service let me know. Thanks

[Teletubbie]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

Bumping my thread since the site was down for maintenance when I posted the resolution.

Thank you all for your help in troubleshooting. It indeed was the diode that was causing the TV to not power up. My TV is now back up and running with the new diode.

I have a few extra SB2100 diodes for free, in case someone needs them for their repair.

[Teletubbie]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

I replaced the bad diode with a new one and powered the TV and it works. Thank you all for all your tips and help without which I could not have done it.

I have a question on the SB2100 diode that I replaced. When I test the diode on the multimeter, it reads .347 both in circuit and out of circuit. Is this okay?

[Moreno83]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

If you don't have solder wick/solder sucker you can heat up the solder and stick a toothpick in it to create a hole. ( as the solder won't stick to wood ).

[calimark]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

I am fairly new to soldering. A couple of questions:

1. To desolder an existing diode from a board, do you heat the joint from the front side or the back side of the board to melt the solder? A youtube video said you should add some new solder to help desolder an existing component. Is this true?
2. When you install a new diode, do you solder on the front side, back side or both?

Yes its true, it helps to get things flowing much faster. If you don't have a solder sucker or wick, you might have a harder time removing it.
It may be easier to clip the diode out and then just de solder the two small pieces left behind. Less metal and no diode eliminates the heat sinking ability and lets you get more heat to the solder joint.

When installing, if you get a good flow- you probably wont need to touch the front side, just the back.

[Teletubbie]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

You should make the diode legs longer so when it is mounted the body will be above the circuit board may be 1/4 inch or so to help aid cooling of the Diode, diode legs are part of the heatsinking.

I am fairly new to soldering. A couple of questions:

1. To desolder an existing diode from a board, do you heat the joint from the front side or the back side of the board to melt the solder? A youtube video said you should add some new solder to help desolder an existing component. Is this true?
2. When you install a new diode, do you solder on the front side, back side or both?

[freakaftr8]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

Good find! Hopefully replacing the diode does the trick. I had seen some power supplies for the transformer get so hot that it makes other semiconductors around it like diodes and resistors overheat and they like to short circuit or open

[budm]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

You should make the diode legs longer so when it is mounted the body will be above the circuit board may be 1/4 inch or so to help aid cooling of the Diode, diode legs are part of the heatsinking.

[Teletubbie]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

Ordered the diode, it will take 10-15 days for delivery.

When I get it, should I do the following?

• Desolder the old diode and remove it
• Cut the ends of the new diode to the same length as the old diode
• Orient the new diode the same way as the old diode and solder it
• Install the board
• Connect the cables back and plug in the power cord

Is there any thing else I need to know?

Budm: Thanks a lot for all your tutorials. Very well written. I read all your troubleshooting and getting started guides before I posted this thread. It was very helpful!
Thanks.

[budm]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

Through hole rivets samples.

[Teletubbie]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

I doubt you will find this Diode at Radio Shack.
Good ideas to might as well test the other devices, you should resolder the transformer legs and devices mounted on the heatsink, you can see that they use the rivets for some of the legs which tend to have cold solder joints, make sure to use Flux.

Can you please point to me the numbers marked on the board to know where these legs and rivets are located? Thanks.

[budm]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

You can get the sub from digikey, just have to match the spec, it will be faster but more expensive.

[Teletubbie]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

I can order it here for $3.50 (lot of 10) with free shipping but it takes 10-15 days for delivery.

[budm]

Re: Sharp Aquos 70" LED LC-70LE632U does not power on

I doubt you will find this Diode at Radio Shack.
Good ideas to might as well test the other devices, you should resolder the transformer legs and devices mounted on the heatsink, you can see that they use the rivets for some of the legs which tend to have cold solder joints, make sure to use Flux.