How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Shahid Your Own Question
Shahid
Shahid, Technician
Category: Electronics
Satisfied Customers: 11445
Experience:  I have been repairing electronic gear since 1993 as a qualified Sony tech
33243543
Type Your Electronics Question Here...
Shahid is online now

Having taken the back off can't find backlight inverter on

Customer Question

having taken the back off can't find backlight inverter on my Toshiba 40D1333B 40" tv. Do you know where it is please?
Submitted: 2 years ago.
Category: Electronics
Expert:  Shahid replied 2 years ago.
Hello, my name is***** be happy to assist you.
Please allow me to ask you a few questions to diagnose the problem.
- Can you please take a picture of rear of TV (showing all the circuit boards in one picture) and post it here or upload it any file sharing site such as http://imgur.com/ and post the file link here so I can view it which will help me to point out required board, however, this TV is LED so it would not have usual inverter board, in fact the inverter section would be on power supply board and a connector would go either to LED drive board or directly inside screen for LED volts.
Thank you.
Customer: replied 2 years ago.

Will arrange to send photo and get back to you tomorrow.

Thanks

Expert:  Shahid replied 2 years ago.
No problem Terry, take your time.
Thanks.
Customer: replied 2 years ago.

I have emailed you a picture of the TV showing circuit boards but you don't appear to have acknowledged that - did you receive it?

Terry

Expert:  Shahid replied 2 years ago.
No, I didn't get that picture, please either email to***@******.*** and they will forward it to me that might take longer time OR upload the picture at http://imgur.com/ and post the file link here so I can view it.
Thanks.
Customer: replied 2 years ago.

Customer: replied 2 years ago.

I sent a picture today as requested to *****@******.*** as not sure how to use 'imgur' Have you received it?

Terry

Expert:  Shahid replied 2 years ago.
Thanks Terry for the image, though it is tiny yet works to view the boards.Please check wires on left side, from power board, going into screen which indicates that it is LED backlight system panel and it doesn't have separate inverter board like old LCD TV.LEDs are utilized for Backlight in this panel and power supply board sends working volts to those LEDs. I trust my input will help you out. Please feel free to respond if you have any additional questions.A positive rating to answer would be greatly appreciated, please click on smiley face/star on this page then click submit/finish button so I can get credit on website for my work. Regards,Shahid.
Customer: replied 2 years ago.

Shahid,I'm not sure which board you are referring to but if it is the larger of the two there are no connenctors on the left hand side. If it is the smaller board you are referring to there are two connections on the left hand side. Which one is the one that goes to the back light and will this board in fact need replacing?

Expert:  Shahid replied 2 years ago.
Terry,
Can you please provide good size picture as I'm having trouble to mark the wires and board on the tiny picture?
Thanks.
Customer: replied 2 years ago.

I will do my best to send you a larger photo tomorrow.

Thanks

Expert:  Shahid replied 2 years ago.
Thank you Terry, it will make things a lot easier.
Customer: replied 2 years ago.

Customer: replied 2 years ago.

Customer: replied 2 years ago.

Customer: replied 2 years ago.

Hi Shahid,

Please find three large photos uploaded.

Looking forward to your reply.

Thank you.

Customer: replied 2 years ago.

Hi Shahid, I have sent you some new photos this morning which hopefully you have now. Basically, all I need to know is which board needs changing to cure the problem.

Thanks. Terry

Expert:  Shahid replied 2 years ago.
Thanks Terry for the pictures, your TV has LED backlight panel and please check following picture where I marked the harness that provide voltage to LEDs inside panel, volts generates in power supply board and main board controls the backlight On-Off so need to check output volts on connector with multimeter marked with yellow circle.It could be either power supply board or main board (green board) problem if no backlight in screen/ screen doesn't glow.
Customer: replied 2 years ago.

Hi Shahid,

Ok, so I have just tested the voltage on both harnesses. When looking at the harness on the bottom left of the diagram that you circled in yellow, the five wires on the right hand side are all 24.3 volts. The three in the middle are all 0 volts and the two on the left are 0.27 and 3.22 volts.

Should these all be the same voltage? Please let me know what we should do now to fix it with this information.

Expert:  Shahid replied 2 years ago.
Do you see any marking on 0.27 and 3.22 volt pins nearby or underneath the power supply board?
Shahid and 2 other Electronics Specialists are ready to help you
Customer: replied 2 years ago.

Yes, number 12. So it is number 11 & 12 that are only 0.27 and 3.22 vots.

What is the solution now please?

Expert:  Shahid replied 2 years ago.
We can't repair the power board on component level and only option is to swap it, get the part number off of power supply board and search/google it to get price and stock info to order it.Thanks.
Customer: replied 2 years ago.

Thanks Shahid, I will purchase a new power suppy board.

Kind regards

Terry

Expert:  Shahid replied 2 years ago.
You're welcome Terry.I trust my input will help you out. Please feel free to respond if you have any additional questions.A positive rating to answer would be greatly appreciated, please click on smiley face/star on this page then click submit/finish button so I can get credit on website for my work. Regards,Shahid.
Customer: replied 2 years ago.

Smile

Expert:  Shahid replied 2 years ago.
-:)
Customer: replied 2 years ago.

Laughing

Expert:  Shahid replied 2 years ago.
Thanks, ***** ***** to reply each response as it blocks my work Que :)