20 Most Recent Philips Magnavox 42MF521D/37 Television - Page 5 Questions & Answers

Check your settings you may have turn off the internal speakers on your TV. You can try resetting everything to the initial factory settings. If that does not work then you are going to need a new signal board. You can get parts at www.interliquidparts.com

go to menu then picture and change it there

The issue is within the power board on this TV.I would look into replacing the power supply board if I where you. Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/edwy_1a56970cf1ea4620

Hello,

there are so many reasons why your TV won't bring out sound. You need to troubleshoot first, in order to get to the root of the problem, before a solution can be proffered.

First, connect a DVD player to the TV, observe if there is going to be sound. If there is still no sound after connecting the DVD player to the TV, proceed to the next step. "The reason why I asked you to connect a DVD player to the TV is to confirm if the problem is simply not from the audio cord connected to the TV."

Second, get an headset, connect it to the earphone jack of the TV and observe if there is going to be sound. If there is no sound, then it is glaring now that your TV is having a defective sound card/IC that's why it is not bring out any sound. (Note that connecting an headset to your TV is optional because not all TV's has a space for headset). "The reason why I asked you to connect an headset to the TV is to also confirm if problem is not from the TV speaker. Though TV speaker problems are rare but sometimes, the TV speaker might be defective or the speaker wires may have loosed contact or cut into two, due to one reason or the other. But if the headset doesn't bring out any sound from the TV, then it is not so."

If none of the above seems not to be the cause of the problem, then the above troubleshooting has confirmed that the TV has got a defective sound card/ic. The sound IC/card of the TV has to be replaced for the TV to bring out sound again.

To be honest with you, replacing or fixing the sound card/ic of your TV requires the ability or experience to do so.

Now, if you are convinced you can fix or replace this yourself, please reply so that i can help you further. And make sure you troubleshoot first, before getting back to me.

Regards,
Walesarumi

you have a short most likely on the power supply but could be on the mainboard, inverter board, av/input board. The T-con board is fused and should blow its fuse before blowing the fuse on the power supply. I'm going with a faulty power supply, most likely a shorted Mosfet.

Yes that is indeed what's wrong no doubt, BUT just replace the entire supply OK, this will sort you out. Repairing the capacitors may return functionality, BUT one must fix the cause too, otherwise it will just fail again soon after. Therefore replacement with a new and tested PSU is always the best way to go..Bad capacitors are caused by AC ripple getting through the circuitry to these caps and slowly destroys them caps HATE AC.

There's a good chance you have failing electrolytic capacitors either in the power section or the inverter section or both.
Any caps in these sections that look bulged at the top, or bulged/leaking at the bottom (look for discoloration of the circuit board around the base of the capacitor) need to be replaced.
If you repeatedly turn it off and on, eventually it'll probably stay on, but every time you turn it off, the unit will get harder and harder to start up until one day it just won't.
Sometimes you have to do the opposite to start it up and unplug it for some time and then try again.

If you aren't tech savvy, don't worry, read the rest of this solution and watch the videos.

If you are handy with a soldering iron and can identify the power supply and/or inverter / FM section for the backlights, an inexpensive handful of capacitors will likely fix you right up.
Match the capacitance on the capacitors. Go over voltage if you can, and still have them fit.
IE - it's not a bad idea to replace a 10V cap with a 16V or 25V or even a 50V, but don't replace a 680uF cap with a 500uF or a 1000uF (unless you are SURE it's only doing supply output ripple filtering,
and even then, you should go OVER, not under the uF rating).

Most of the caps that go are 10V 1000uF or 3300uF.

I found some great videos of the procedure (for many Samsungs with the same issue) on youtube.

http://www.youtube.com/watch?v=Mm51C_RDIZE
http://www.youtube.com/watch?v=BNHHrgX_6cs&feature=related
http://www.youtube.com/watch?v=8l0AUj8QUkg&NR=1&feature=fvwp
http://www.youtube.com/watch?v=Y7b_nTaZYcU&feature=related

Backlight related video here:
http://www.youtube.com/watch?v=6XoF6QZ1dmw&feature=related

As you can see, this issue spans plasma TVs, as well as large and small LCD TVs and monitors, amplifiers, computer power supplies and motherboards, and other electronic equipment.
The parts are cheap, and skill required is minimal.
A great parts source is Digi-Key, and you can order the parts online at www.digikey.com
They typically cost under a dollar a piece plus a flat shipping rate.
The parts usually arrive one business day later.
If you watch the third video, you will see that even someone with no soldering experience can perform these repairs as demonstrated by the woman in the video.

I put heat-sinks on U14 and the regulator above it and the TV has been running fine all day. Always shut off after 14-30 minutes before. Heatsinks were just 1/2" x 1" metal strips with silicon thermal compound that I taped up to hold in place to temporarily test, as it is obviously a heat related problem.

If you try it and it works for you, post it here.

[email protected]

solution A
Step 1:Check your E.H.T.(Extra High Tention)
Step 2:Check your youke koil
Step 3: Check your video I.C.
solutionB
Step 1 :At fast check your speaker.
Step 2 :Test the ON/OFF volume switch.
Step 3 :Test audio IC for pcb.

ck resistor 3318 100 ohm on pwr supply

Hi,
If you can see the menu on the screen it only shows that the LCD panel and T-con board are working fine. This kind of symptoms indicated that the Video processor IC's and its circuitry in the Main board is not working.

First thing to check is the supply voltage coming from the power supply board feeding the main board's connectors. If the supply voltage is not present it will disable the circuitry and trigger that kind of symptoms. Once the supply is not the issue, you have to replaced the entire main board if you are going to DIY because this board is repairable only at the Service Centers, the IC's and other parts are surface mounted and quite sensitive from ESD. This is repairable but needs to troubleshoot.

If your TV has no any problem before aside from this kind of fault, I would advice you to let it repair because it will save you some money rather than buying a new set but its up to you, ask for an actual estimate first from your local repair shop for service fee plus parts lets say the main board to have an idea how much money you are going to spend sending it in.

If you don't have necessary tools and test instrument and can't troubleshoot the unit yourself, I would advice you to look for a professional to isolate the problem.

Hope I helped you.

Have a nice day!

Thanks for using Fixya.

Unstable power supply due to bad DC filter caps, bad backlights inverter board, main board.
Please read my guide first so you will know more what to look for.
Basic LCD monitor and TV troubleshooting guide: http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting http://www.fixya.com/support/r7406380-tv_training_manuals Failed TV and Monitors pictures: http://s807.photobucket.com/albums/yy352/budm Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague Parts: www.shopjimmy.com Parts: www.interliquidparts.com Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx he can make you a set of caps. Or www.digikey.com, just make sure to use caps with low ESR, 105c, high ripple current and long life rating such as PANASONIC FM or FC series.

Problem could be in the Main unit Board, check out www shopjimmy.com

There's a good chance you have failing electrolytic capacitors either in the power section or the inverter section or both.
Any caps in these sections that look bulged at the top, or bulged/leaking at the bottom need to be replaced.
If you repeatedly turn it on, eventually it'll probably stay on, but every time you turn it off, the TV will get harder and harder to start up until one day it just won't.
Sometimes you have to do the opposite to start it up and unplug it for 5 mins, then try.

If you aren't tech savvy, this unit needs to go in for repair.

If you are handy with a soldering iron and can identify the power supply and inverter / FM section for the backlights, an inexpensive handful of capacitors will likely fix you right up.
Match the capacitance on the capacitors. Go over voltage if you can, and still have them fit.
IE - it's not a bad idea to replace a 10V cap with a 16V or 25V or even a 50V, but don't replace a 680uF cap with a 500uF or a 1000uF (unless you are positive it's only doing ripple filtering).

Most of the caps that go are 10V 1000uF or 3300uF.

I found some great videos of the procedure (for different brand, but same issue) on youtube.
http://www.youtube.com/watch?v=Mm51C_RDIZE
http://www.youtube.com/watch?v=BNHHrgX_6cs&feature=related
http://www.youtube.com/watch?v=8l0AUj8QUkg&NR=1&feature=fvwp
http://www.youtube.com/watch?v=Y7b_nTaZYcU&feature=related

As you can see, this issue spans plasma TVs, as well as large and small LCD TVs and monitors.
The parts are cheap, and skill required is minimal.

Look for more caps, and start checking transistors.
See my tip in tips and tricks for checking transistors.

The TV is running 24/7 even when you turn it off, it is because the power supply and the processor has to be running so it will turn on the rest of the circuits when it gets the command from the remote or from the power switch on the TV.
More likely the power supply had died.
If you are going to DIY and have proper tools, electronics knowledge, and know safety precaution then please read on: Basic LCD monitor and TV troubleshooting guide: http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting http://www.fixya.com/support/r7406380-tv_training_manuals Failed TV and Monitors: http://s807.photobucket.com/albums/yy352/budm Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague Parts: www.shopjimmy.com Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx he can make you a set of caps. Or www.digikey.com, just make sure to use caps with low ESR, 105c, high ripple current and long life rating such as PANASONIC FM or FC series. Please post back what you find. Please leave rating if it helps.