Facing TV Problems? Ask a TV Technician.
Hi and welcome to the site, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.
Initially, have you tried unplugging the TV for an extended period of time? ...the idea is to simulate a soft RESET.
And then plug back in but use a different outlet.
An hour or so. More if to dissipate residual power.
This is the only easy user doable try/test as all others would be internal to the TV.
Yes please and post back with an update when able.
Then it would confirm the internal hardware issue.
Bear with us; re-confirm and post back with the complete model number of the LG.
Are you then considering a DIY (do-it-yourself) repair approach? If yes, do you have access to and familiar with a multi-meter?
Great on the DIY and appreciate the additional information.
The description of "...black screen...dim picture..." would point to the backlighting system as the most likely suspect. Since this is a LED TV, then the primary suspect would be the LED driver that provides the needed supply voltage to light up the LED arrays.
Also, this particular model has the LED driver co-located on the same board as that of the power supply. With this in mind, proposed approach would then be replacing the power supply board.
On most versions, the Part Number would be something like LG EAY62810701 (3PAGC10124A-R) subject to confirmation on the actual/current power supply board.
Please click HERE to inquire for a replacement board (availability/cost/shipping)