How do i update firmware on magnavox 37mf331d/37

Fault with the main power supply regulator section. Either it will be on a separate board, or on the part of its main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/

Fault with main board. Damaged component/s at it. Contact any service technician; or the authorized service center. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. http://electronicshelponline.blogspot.com/ . In most cases, the main board might have to be replaced. If so, a software [firmware] update too might be necessary.

Contact the authorized dealer for Magnavox. They can help you.
http://electronicshelponline.blogspot.com/

For magnavox/Philips model #37mf331d/37 part# is 313815864961.

You have a bad Capacitor or two!

There are two places to look for the problems, the backlight inverter board and the power supply. Look at the power supply first since it is easier to get to, look for burnt parts, bad capacitors, etc.
http://en.wikipedia.org/wiki/Capacitor_plague
Please post back what you find.

The problem can be in the backlight inverter board (hard to get to), or the main power supply module may not be working. Look at the power supply first since it is easy to get to, look for burnt parts, bad capacitors.
http://en.wikipedia.org/wiki/Capacitor_plague
Please

I had the same problem with a Magnavox LCD TV. It would not turn on and the light on the external PSU flashed. I found a replacement 12V 5A power supply on EBAY. It brought the set back to life.

Your set either has a bad SSB (small signal board) or needs a software upgrade. Try the upgrade first by going to http://www.m4c.magnavox.com/cgi-bin/dcbint/cpindex.pl?scy=US&slg=AEN&cat=FLAT_TV_CA&sct=LCD_LARGE_30_40_SU&grp=TV_GR&session=20090830171041_4.131.87.247&ctn=37MF331D/37&mid=Link_Software&hlt=Link_Software
Download the latest software release for your set then follow install instructions that are contained in the user manual for your set.

Disconnect the LVDS Cable that runs from the small signal board to the display panel and apply power,if the screen comes on,the Small signal board (aka Scaler Bd ) is the faulty board. other than that,all that's really left that has gone bad for me is the logic board.