Re: JVC LT-42EM59 no picture no sound
I apologize for my hiatus. Work has had me on the road weeks at a time. I am home now and am able to finish this up.
I found two transformers. I unplugged the inverter board and on T9501 I measured the following:
1-3 .1ohms
4-5 .1ohms
7-8 .1ohms
9-12 .2ohms
On T9201, I'm not sure what you want me to measure. I have attached snips from the manual depicting the transformers.
Are we saying the power board is the issue?...
bayougrizz
Member
Last Activity: 01-11-2016, 07:06 PM
Joined: 09-30-2015
Location: albany
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Re: JVC LT-42EM59 no picture no sound
Do I put everything back to factory positions, or do I leave the resistors in place? Is this with just the tv plugged in?
Thank youLeave a comment:
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Re: JVC LT-42EM59 no picture no sound
I followed the instructions in budm's post #34, except for that I dont have that wire in PWM_DIM.
I left everything plugged in and just removed the BL_ON pin from the CN9006 connector, then added the resistors.
I turned off the lights and made the room completely dark so I could try to see if something would flicker when I pressed the power button...it seems like the backlight is what's flashing, once, for a fraction of a second when I press power. Then, ten seconds later or so, I hear the board click again and it has...Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I have no wire in PWW_DIM.
I placed two resistors coming out the back of STB5V. One resistor jumped from there to DC_DIM.
I took out the wire from CN9006 Pin 1 (BL_ON). The other resistor went from STB5V to this pin location.
I plugged in the TV, pressed the power button and heard the click. It still clicks back "off" after about ten seconds. Still no picture. I cant see anything with a flashlight either. I did measure 5VDC at DC_DIM and BL_ON.Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I ask for a day or two to get back to this project. Work has been keeping me very busy. I didn't want you to think I've abandoned this. Thank you for your patience.Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I measured 0VDC with just the TV plugged in and after I pressed the power button, I still have 3.1VDC on each of those points.
So, now do I do the resistor checks like this?:0
Unplug CN9005 and CN9006. Place resistors between STB5V and CN9006 Pins 1,4,6, and 8. I'm guessing I use the male pins on the power supply board so that we can send power to the back light inverters??Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
Just so I understand and not just got through the motions:
Unplug CN9005 and CN9006. Place resistors between STB5V and CN9006 Pins 1,4,6, and 8. I'm guessing I use the male pins on the power supply board so that we can send power to the back light inverters??
Also, capleaker, i see no picture when I use a flashlight.Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I dont have any 1k ohm resistors, so let me grab some at radio shack today. I'll get you the results as soon as I can.Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I had time to grab the voltages on pins 1-15 again before work this morning. I will have to take the board loose to get to the cap pins later on today. Pin 15 was 24VAC, sorry for the messy hand writing.
have a good one...Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I apologize, but which connectors would you like me to check voltage on now? Are you talking about the set between the power board and the Master backlight inverter?
With the TV just plugged in, or with after I actuate the power button?
Also, which is the filter cap?
Thank you for the patience.Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
No wires in Pin 4,5,7,9, or 10. Pin 1 measured .740VDC with the power on. Pin 4 measured .5VDC and Pin 5 had no voltage.Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I got 3.1VDC on both pin 6 and 8 on CN9006 this time. When I press the power button the relays click and about 10 seconds later they click again (apparently off I reckon). I didn't realize this the first time. I had to be quicker to catch the voltage reading.Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I must have had a loose connection or something, but at any rate, I re-seated every connector carefully and remeasured with the TV plugged in and then again after pressing the power button and hearing the relay(s) click. I checked them at the power supply board and at the signal board to make sure there wasnt a connector or wire issue. The batteries in my meter are good. I keep them fresh as I use this meter for work everyday..but thanks for bringing that up, I have made that mistake in the past!
There is no wire on Pin 6 (STB3.5V),...Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I used to be able to plug the TV in, hit the power button and the relay(s) would click. Now I am having trouble with that. While measuring voltage for you guys, I was not able to get anything to happen when pressing the power button.
See voltage readings attached....Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
CapLeaker,
here is the pin out you were looking for. I found the manual for this tv in a past thread on this forum....Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
I measured voltage on all the pins on both connectors CapLeaker mentioned. Now, I unplugged the connectors from the power supply board and measured from each pin to ground. The only one I got voltage on was pin 5 of the CN9005 connector at 6VDC. Most of the rest measured 0VDC. On that same connector Pins 10, 9, and 7 measured .357VDC.Leave a comment:
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Re: JVC LT-42EM59 no picture no sound
Here are the pictures you requested.
Thank you for answering my post....Leave a comment:
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JVC LT-42EM59 no picture no sound
I have the above TV with no picture and the best I can tell no sound either. I found another thread with a similar issue, but after following those posts, I believe I have a different issue.
Could someone please help me determine the issue so I man order replacement parts?
I hope the board pictures are sufficient. If I need to more and focused on a particular area, I certainly will.
Thank you...Last edited by bayougrizz; 10-04-2015, 12:24 PM. -
Re: New Members - please post your introductions here
My name is Nevin.
I have a background in control panels and instrumentation, but not very much experience in the A/V field. I am hoping to learn a few things by getting some help on some devices I have.
I have read through several posts and believe that this is a great forum for assistance.Leave a comment:
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