20 Most Recent Samsung LN40A450 LCD TV Questions & Answers

The TV is how do they say that "Kaput"

the main board probably has a crack in solder joint some where.

You have to check all the voltages, that comes from its main power supply board, to its back light inverter board. These is one pin at the backlight inverter board; comes from the main board; which controls the back-light inverter to start and off. This voltage is generated at the main board, and send to the back-light inverter board, as control voltage. It will be best to contact any service technician. If you wish to get some details; check the site linked here.Viewing it in "Mosaic" will make surf easy. http://electronicshelponline.blogspot.com/

Main digital board fault. Replace it. Contact any service technician. If you wish to get some details; check the site linked here. Viewing it in "Mosaic" will make surf easy. http://electronicshelponline.blogspot.com/

These blinks are fault indication, and known as blinking codes. From the number of blinks occur at one time switch ON; you can get an idea about the faulty circuit stage inside the TV. This will make repair easy. For more information, check the link http://electronicshelponline.blogspot.com/

Hello Jon,Before you start ordering and swapping parts check with Samsung, that model is covered under the terms of the class action lawsuit settlement over bad power supply boards. The power supply boards cause the exact symptoms that you are having. They should repair the unit free of charge for parts and labor. Here is additional information on the settlement along with contact information. http://www.ccl-la.com/blog/index.php/samsung-has-reached-a-settlement-in-class-action-lawsuit-over-faulty-tv-power-supplies/

unfortunately samsung wont produce full schematics since they want board replacement repairs only. But you might get some free tech support from the guys at www.tvrepairworld.com

unplug the tv for a while.

I will explain how to:

• Open the case of the LCD

basically in all LCD monitors have two circuit boards (power supply board and system board)

• After you open you will see the two boards are

• You see a board that has a socket for the power source. wrote that the board we're looking for (power supply board)

• Remove all cables connected to the board and take out the board. (get noted before you unplug it)
  

• Now you see it components on board, we looking for capacitor.(see picture below)

• Looking for damaged capacitors, physically you will see a capacitor on the top like a bloated (see picture below)

• Replace the damaged capacitor with the same value that you can see on the surface of the capacitor. (In this step you need any soldering tool)

My advice: replace capacitors with higher voltage, like 10V replace with 16V or 25V will be fine.

Your power supply needs repaired. You can pay someone to do it locally... or you can do it yourself. I have a tutorial on this repair published on this site. Check it out if you like. I hope this was of some assistance.

in the menu under setup there is a factory reset when you do this it puts the tvback to the way it was when it came out of the box we have knoticed that for some reason hdmi connectors are subject to surge and power problems not exactly sure why but a main board replacement might be needed

You have a switching problem. A MOSFET transistor component or a leaky capacitor problem. You need servicing Sir/Ma'am.

First place to look will be the power supply module, look to see if it has blown fuse (F1), or if it has any DC output voltages.
See the boards here: http://www.shopjimmy.com/catalogsearch/result/index/?q=Samsung+LN40A450&limit=15

Learn about LCD TV here:
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 pictures: 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.