SONY LED TV Model KDL-32BX310 Hit By Power Surge
A few days ago I noted power in my estate was dim and being an electronics technician with basic knowledge in electricity I decided to visit my electricity meter to find out what is happening.
My meter is three phase and after checking other two lines, I noted they have more than normal voltage, actually 421 VAC instead of 240 VAC here in Kenya.
I logged on to our estate what’s-up group and broadcasted that power is abnormally high and therefore those with electrical equipment should disconnect them from the power outlet.
Before finishing writing the text I noted unusual influx of comments coming from every corner of the estate with complains of equipment’s smoking and instant dead.
Since I had warned them about the abnormal high voltage, I send them my condolences for the loss (dead) of their equipment and assured them that hum-tech electronic is open 24/7 to see them back on air seamlessly.
Orders started trickling in and my first order was from my good friend and neighbor who lost is Sony SONY LED TV MODEL KDL-32BX310.
From my experience when equipment’s are hit by power surge, the culprit is usually the power board, I visited the home, opened the television and picked the power board and off I went to my workshop.
One my workshop bench, I began by scanning the board with naked eyes and seems like no catastrophic damage on any component.
Power board bottom side.
I pulled my meter and tested the fuse and was found okay, the bridge rectifier was also found okay, on close observation I noted the top of the main capacitor was slightly swollen and this is an indication all is not well with this capacitor.
I changed it directly since there is no point of testing a swollen capacitor, whenever you get a swollen capacitor kindly send it directly to the dustbin and that is exactly what I did.
After replacing this one capacitor I decide to use my series bulb current limiter (you can make one easily by visiting this link)
I applied the power and the bulb was bright then dim, with this I concluded the power supply had no other shorted component.
I checked the output voltage and got the 3.3 volts standby, I used a 10K resistor to link between the standby and power ON pin and other voltages were generated and with this I concluded the power supply is okay.
Off to my friend home and I re-installed back the power board and after applying the power the television came up beautifully.
Thank you friends
Latest Ebook in LCD/LED TV Repair
Humphrey Kimathi is from Nairobi Kenya and the author of CRT Troubleshooting guide, DVD Player repair guide, CRT Television repair course and Basic Electronics course. He is also a blogger at Electronicsrepairmadeasy.com
Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.
P.S- If you enjoyed reading this, click here to subscribe to my blog (free subscription). That way, you’ll never miss a post. You can also forward this website link to your friends and colleagues-thanks!
Note: You may check out his previous repair article below:
About admin
Jestine Yong works as an Electronics Repair Lecturer in Kuala Lumpur Malaysia and his training website is http://www.NoahtechElectronicsTraining.com. You can check out his repair blog at http://www.JestineYong.com
23 comments on “SONY LED TV Model KDL-32BX310 Hit By Power Surge”
Leave a Reply
Leave a Reply
This site uses Akismet to reduce spam. Learn how your comment data is processed.
Excellent! A good public service too!
Thank you Parasuraman,
Regards Humphrey
Thanks for article Mr.Humphrey.it’s simple but very tricky and that explains why visual inspection is vital in electronic repair.l am requesting you to throw more light on the use of 10k resistor to determine the output voltage plz.Meanwhile happy New year Mr.
Hi Oloo, If you apply power to a new s.m.p.s(eg.ATX or led/lcd tv power board) you will note that the 5Vsb is always presents if the power supply is okay and no other voltage will be present if the power board is disconnected from the from the main board. To get other voltages you will need to link up the 5vsb or 3.3 vsb to the Power-ON pin and other voltages will be generated… the 10 K resistor act as a load also.
Regards Humphrey
Noted Mr Humphrey.Thanks
Excellent. I’m Nairobi, where are you based.
Hi Dickson.
You can get my contact on my blog.
Regards Humphrey
Interesting repair! What made the Power Lines go up that high? Maybe losing the NIL Line connection? Between a single Line of the R,S or T Phase (120 degrees shifted) and NIL Lines the effective AC Linevoltage is 0.707 x U peak = 240 VAC eff. So Upeak must be 339.46 VAC. And between two Phase Lines this means a Phasevoltage of 400V (which was 380VAC in the time we still had 220VACeff). Which probably had killed those devices.
Hi Albert, Quite interesting postmortem there, that exactly what the power man explained.(the ground/earth lost connection)
Regards Humphrey
Are you sure that the Powerman spoke about the Ground/Earth line that was lost Humprey? Because the Earth Line is only an extra safety Line to prevent us from getting electrocuted when a metal electricity conducting device leaks the deadly Phase voltage on its external housing. And this Earth Line therefore shortcuts this dangerous voltage directly to Ground/Earth. I guess that here only the absence of the NIL Line could have been causing this too high 420VAC problem? I hope you also have a safety earth fault circuit breaker (RCD?) at home that immediately disables the PowerLine in case a current leaks directly to Earth.
(it breaks the circuit at a current at which it could cause a deadly heartfailure).
What? Albert! …Think I need one hour session with you on electricity..Netherlands am coming haha
good job sir
Thank you Sir
Regard Humphrey
a job well done. keep up the good work and many blessings to you
Thanks Waleed, loong time! all the best in the new year my friend.
Regards Humphrey
Good article Mr Humphrey.could you explain where the ON pin is located.
Hi Festus,
The pin is usually well labeled on the pcb board(eg Pwr-On)
Regards Humphrey
interesting article Humphrey. Quite educative. i like it
Thank and welcome Tito
Regards Humphrey
Great repair. Congrats.
Thanks Humberto
Regards Humphrey
Hi Humphrey. Thank you for your well explained article. One important thing I have learnt in your article is how to activate other voltages using the standby voltage and power on pin. Thanks so much
Thanks for your feedback my friend Jumbe, Glad you have learn something new..keep learning
Regards Humphrey