Here’s another video of a LCD TV repair made on a Magnavox 15MF170V/17 which is a small 15-inch flat panel TV. The malfunction is characterized by a blank white screen when you power up the unit. There is audio coming out but the screen is just white and not displaying any pictures.
The repair video showed that this problem is being caused by the absence of electrical input which is needed to power the electronics of the LCD screen such that all you are seeing is the LCD backlight which is white.
The problem was traced back to a faulty MOSFET (metal-oxide-semiconductor field-effect transistor) which is a very small 8-pin chip that acts like a switch that allows electricity to be fed to the LCD electronics.
The fix involved replacing the MOSFET but it does not show the actual process of removing and then replacing it with a new one so this is not beginners stuff. The transistor is very small and the video even said that it is a bit tricky to work on without the appropriate tools.
Important thing is to determine first whether you are having the same problem by checking if the LCD is really not getting any power using a digital multimeter on the connector pins that was pointed out in the video.
If you need the schematics for this product, you may check out another post of mine that discusses where you can possibly find LCD repair manuals and other relevant data sheets for the needed parts.
As always, handling electronics is an activity not to be taken lightly. Be sure to take all the necessary precautions. If you are a beginner, it is recommended that you take an LCD Repair Course first.
Head on over to the video’s Youtube page to get more information about this LCD repair project.
I have 15″ flat screen LCD Magnavox TV that is totally dead. It is a model # 15MF227B/27. The red “on” indicator light is on constantly and cannot be turned off other than unplugging the power supply. The power supply is putting out 15.85 volts and it is supposed to be 16 volts, but since it is well within 5% of the required 16 volts, I do not believe it is an external power supply problem. I think this TV is 3 or 4 years old but don’t really remember when I bought it. This TV was rarely used and only has about 20 hours on it at the most so I was surprised when it quit working. I removed the back and looked for obvious problems like swollen electrolytic caps, etc, but couldn’t see any obvious problems. In addition, nobody in Western Michigan seems to want to work on Magnavox TV’s. Seems like the problem is in an internal power supply circuit to me. Do you have any suggestions on what I should look for? I have several diagnostic pieces of equipment available for use, but no schematics for this TV and am familiar with older solid state/CRT TV repairs. Thanks.
Harvey
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Great..thanks for the video as it shows visually on defective board.I came across that kind of problem exactly the same but by other brand,it made me lot of headache on how to repair it.I just want to ask how did you know that the problem is actually the mosfet?Can you explain that using the schematic diagram on that brand?That’s what i wanted to be familiarize that kind of problem.Maybe because of many years repair experience you had.That’s what it takes to be an experience repairer.Actually i am only a beginner aspire to be a professional someday.great help..thanks..
I am having the same problem, and will need to have my TV fixed too. Thank you SO much for helping me to identify the problem so I can explain to a technician. I’m not sure that I can replace it myself unless a MOSFET can be purchased locally. Thanks again.