I trying to find the correct size screws to attaché the bracket to the bck of tv 50 pc3d-u

Screws for Mounting TV to Wall Bracket:
The most common screw for securing the TV to the wall bracket is an M8 screw. The other screw sizes for some TVs are M4, M5, and M6. The length will be determined by the type of TV you have.
https://removeandreplace.com/2016/10/18/tv-wall-mounting-what-type-of-screws-do-i-need-from-wall-bracket-to-tv/

https://www.google.com/search?q=I+have+a+Wall+bracket+screw+size&tbm=isch&source=univ&sa=X&ved=2ahUKEwizwvWc7rroAhUDy4UKHTGTBW0Q420oA3oECAcQCQ&biw=1326&bih=627

VESA Specifications
VESA STANDARD HOLE PATTERN SCREW SIZE MONITOR WEIGHT SCREEN SIZE FDMI MIS-B 50 x 20 mm M4 x 6 mm ? 4.4 lbs / ? 2 kg 4" to 7.9" FDMI MIS-C 75 x 35 mm M4 x 8 mm ? 10 lbs / ? 4.5 kg 8" to 11.9" FDMI MIS-D 75 x 75 or 100 x 100 mm M4 x 10 mm ? 30.8 lbs / ? 14 kg 12" to 23.9" FDMI MIS-E 200 x 100 mm M4 x 10 mm ? 50 lbs / ? 23.7 kg 24" to 30.9" FDMI MIS-F 200 mm increments M6 x 8 mm or 10 mm;
M8 x 15 mm ? 250 lbs / ? 113.6 kg

Dear Billy,
It is very difficult to determine what size screw for the TV bracket.

• If you bought a wall bracket, it will definitely have different sizes of screws in it.
• Follow the installation guide for what Size screw to use on the TV. It varies by manufacturers.
• Get a Universal Bracket.

Good Luck!
JP

sounds like the wrong bracket for that TV.

Most wall brackets (generic) come with the hardware--if not consult the maker of the set for the length and thread type of the bolts.

The stand comes with several different size screws, Did you not get the screws that came with the bracket?

Yes, you just have to remove the stand first, the screws will be Metric M5 or M6 that you can get from HD or LOWES, the length will be depended on how thick the bracket is.
When you buy mounting bracket kits, it should come with a bag of screws for attaching the TV to the bracket.

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

If you are talking about the mounting screws that go into the back of the television to mount a VESA sized wall bracket, then it's most likely 5mm screws. The length of the screws could differ, depending on the bracket you are attaching, but usually 12mm or 16mm can be used. just make sure that the screws are long enough to thread into the TV completely, but not too long, or they may damage internal components.

If you are talking about the Lag screws needed to mount the bracket to the wall, then use 3/8" width lag screws 2 1/2" to 3 1/2" long, depending on how deep you have to go before hitting the wood stud.

Metric M5 or M6, when you buy wall mounting bracket, it will came with a bag of screws for attaching the TV to the bracket. All my wall mounting brackets for my TV come with screw.

http://s807.photobucket.com/home/budm/allalbums

The screw holes are metric. The set is supplied with M5x25 screws to attach the pedestal, so the wall mount screws will be in that same range.