LG 37LT 75 faults Picture freezes everything locks only solution is to pull plug and then restart. Occasionally just get black screen whaen changing channels. Recordings failing due to "time setting error" or "poor signal". This is not the case. Message that channel info. has changed and have to re-scan to remove message.

Do you have a multimeter and able to pull the back off and get some voltage readings?

If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
Line faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.

If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
Line, faults & possible causes to both Plasma & LCD screen are given with illustrations. You can get an idea about the fault to an extent.

There is an fault for sure. When you are not a tech, you don't have to know what is wrong. So when the solution from The Knight does not help, contact a tech or visit a repair shop. Ask what they will charge in advance to see if it is worth repairing the TV.

If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
Line, faults & possible causes to LCD screen are given with illustrations. You can get an idea about the fault to an extent.

check your input cable

First of all, shame on LG for not providing support on their product. It sounds like this TV isn't that old. I was just bragging on them to several people this week. Your symptoms sounds like a main board issue. But in order to be sure, proper troubleshooting will need to be done to pinpoint the problem. You will have to pay a diagnosis fee, usually $75 range, but for a 55" late model set, I would say it is worth the money. So sorry to hear this, I'm hearing so many of these late model LED TV's failing left and right.

u need a new phone i ahda similar problem with my lg kp500

I think the problem stems from the HDMI port and scart ports, i have read somewhere on a sound and vision web site that these two conflict and when HDMI is in it only sometimes blocks out the scart signal. This could be what the problem of the freezing is, as when all said and done its just a very large pc monitor; and look at the trouble they can get in!.