I would bet your TV has a Cold Cathode Fluorescent Light (CCFL) backlight. There are a couple of small tubes, on the top and bottom edges of the panel. I don't know what the voltage is on a larger screen but on a laptop or even a 20" monitor it's like 800-1000 VAC so it's a good thing you asked. The HV is generated by a small inverter and connected to the CCFLs with some silicone wires of maybe 1 mm diameter similar to but smaller that those used with a CRT. If you have a 'scope, it can usually pick up the field from the inverter just by getting close to the wires. I believe the frequency is something like 20-40KHz. I wouldn't try to measure the voltage unless I used a HV differential probe that could safely handle KV AC signals.
Try looking for Samsung LCD TV backlight
BTW, If you've been out of computer and display repair for a while, one thing you'll find is that electrolytic capacitors, especially in power supplies, don't last all that long even for reputable manufacturers like Samsung. Look up bad capacitors.
Best o' luck