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.
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.
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?
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?
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.
@@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.
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?
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?
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.
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 👍👏🏴👍👏🏴
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.
@@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!!
hoping someone can point me in the right direction with these readings i have on a 70 vizeo i would like to keep please 1.gnd-0 15.T-con_on-0 2.gnd-0 14.12vs-167.5 3.24v1-24.6 13.12v1-0.4 4.24v1-24.6 12.nc-6.4 5.24v1-24.6 11.nc-0.55 6.24v1-24.6 10.nc-0 7.24v1-24.6 9.+12v1-12.6 8.24v1-24.6 8.+12v1-12.6 9.gnd-0 7.gnd-0 10.gnd-0 6.gnd-0 11.gnd-0 5.gnd-0 12.nc-7.5 4.12vs au-12.75 13.nc-0.1 3.ps_on-2.3 14gnd-0 2.ac_det-3.8 1.nc-80.1
