How to Troubleshoot Power Supply with no Standby voltage. Sony KD 70x690E led TV repair.
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- เผยแพร่เมื่อ 16 ก.ค. 2023
- Here we have a 70 inch Sony Bravia 4K LED Smart TV model KD-70X690E with no picture, no power, and no standby light on the bottom of the television. TV is totally dead. The primary side voltages are fluctuating and no secondary side voltage rails are coming up, including the 5 volt standby voltage. I will show you a secret method to isolate if the problem is on the Primary or the Secondary side of the Power Supply. This is a complete troubleshooting method that you can use on any Switch Mode Power Supply board.
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Switch-Mode Power Supply Course: bigdogtvrepaircourse.mykajabi... - แนวปฏิบัติและการใช้ชีวิต
You are born for a teacher.
Thank you.
Far and few are able to convey knowledge . More importantly actually make the experience comprehensive
Love your work. Cheers!
Neat trick to bypass the optocoupler and verify that the problem is somewhere in that feedback circuit.
This is the kind of thing I most enjoy learning.
That's a deep understanding of the circuits with amazing casual manipulation. The only thing I could relate to is that the voltages should be stable; I think I've confidently ruled out my power board. Thank you.
Great to watch a professional work his magic. Wish I had this knowledge before spending $200 on parts for a Smart 58" tv that I couldn't get to come on. New main board, power board, & T-com board did nothing. Worst part is, Jimmy's tv won't take the parts back.
Great video, loved your debug process :) Helped me fix my parents TV too which is awesome, thanks!
yes, your testing is very keen on the board and traced the power fault accurately thanks to your theory.
Hello from Melbourne. Your repair video came just at the right time. I was given a 60 inch Sony with exactly the same fault. Thanks to you the set has been saved from going to landfill. You have inspired me to use my electronic background more. Keep up the great work.
EXcellent! Make sure you check out the Course too.
bigdogtvrepaircourse.mykajabi.com/
Excellent repair video. Thanks 👍
Excellent instruction... just found this video. Thank you for the post.
Great repair and tips!!! My humble thanks.
You bet
Brilliant fix mate nicely done 😊
Thank you! Cheers!
please use flux when desoldering it helps with not destroying pcb traces and pads.
Great troubleshooting... Bear down
Thanks!
Good job .thanks .
Welcome
Thanks! So why did the diodes go in the first place Bigdog?
Just component failure.
nice
Thanks
i cant buy the SR5150 diodes in my area. Can you give me a few reccomendations fro other? Also can you tell me the minimum forward voltage, current and reverse voltage required for these diodes?
Hello, can the SR5150 be replaced with a different type of diode? I don't have those easily available to me locally.. Thanks
👏👏👏
I have a Samsung un55nu7100. No stand by light. Won’t come on or do anything. I’ve replaced power board and main board and still nothing. Led voltage are 3-5v when they should be 12.8. Is the back light bad?
Another great upload. Big Dog. 8882. Please can you send me any information on how I can join your tutoring. Many thanks in anticipation regards, Brian 👍👏🏴👍👏🏴
Any time Brian!
bigdogtvrepaircourse.mykajabi.com/
Hi ,love your videos and your setup..
I have a Sony Xbr65x850g ,i have 6 blink red light ,white screen , no sound ,Theoptical input shows power on mainboard ,Not sure where to start testing . Im stumped .
6 red blinks on Sony usually means you have bad led strip(s). But if you got a White screen, that means backlights are working. So Im stumped too lol. Check T-con board.
@@bigdog8882 Great thanks ,ok ill give it a try ,has for no sound would that be on tcon as well on somemodels attached to the display
@@jeffcaidler572 No , the mainboard produces the sound.
@@bigdog8882 Ok ,makes sense , i guess illtry the mainboard
@@jeffcaidler572 For sound problems always check the speakers first b4 you change Main board. Put meter is resistance mode and make sure the ohms match whats written on the speakers, and not reading open.
JVC, LT-32A100 switching on tv after 15 to 20 mnts the brightness increases and the screen goes black, the indicator light and sound good, backlight stayed with very low power. When powering on from the remote, the picture comes on but then 15 mnts later goes away This happens again and again. Need your help, plz give some tips to guess which board may be faulty.
How can you tell if a mosfet driver IC is dead? It is easy to determine that when the mosfet is driven by a singe tiny smd transistor but gets difficult when an IC is used.
There are a few things to check like, Vcc, output signals, gate drive, shorts on Vcc line, start-up, etc. All of that is covered in the course. Good question tho.
@@bigdog8882 I know output signals is a major factor but I forgot to mention that I do not own an oscilloscope. I was wondering if my meter would still read the frequency?
@@AK2I47 Maybe, but the only problem; depending on the meter is, it may not be accurate and you want to actually SEE the signal and duty cycle.
@@bigdog8882 Once I get KHz that should be good
I hear you but the video part of your show is blacked out 🤔
I just saw and heard the video... it worked for me.
Depends on the price of a new board but I did not like Sony for televisions.
I fixed my backlight on my Sharp 70 inch tv and it has worked for a while but now the left side of the tv i black the right works fine what else can be wrong?
probably backlights. U have to check the return line on that side thats dark.
@@bigdog8882 ok every ledlightlamp is shining maybe it s the contector on the panel thats burned or the panel is broken
@@bigdog8882 can a panel be half broken? i cant see any crack in the left panel side .
@@bigdog8882 after a couple of hours tv running. tv left panel side show green vertikal lines so i guess some connection is bad
@@bigdog8882 i made a Hard reset and took the cables behind out and put them back again and the start cooling the tv with a fan so now it works fine
Why not ground pin 4?
I dont think that would work cause the opto would still be in the circuit. Then that would be like removing the 2 opto pins and shorting the 2 traces together instead of using a diode.
Good question.
@@bigdog8882 I assume when that opto transistor turns on Vce is near zero? On the other side they have a resistor across the LED, .5 volts seems reasonable. This is why I need schematics for TVS, I can't visualize it in my mind, like a deer in headlights. If you put it on paper I get it all day. I like bread boarding stuff like this, measure it and understand it, but with paper I'm lost. I'm getting fed up with Ebay buying parts, they advertise OEM quality parts but that's not what you get. Its full of fakes and knockoffs. We need radio shack again!!
@@vernonbosshard9317 I think radio shack was my favorite store. So sad they closed down. They were all over Chicago like liquor stores. lol.
*Promosm*