If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience.
http://electro-medical.blogspot.com/http://electronicshelponline.blogspot.com/
Search the site by type in the "Brand Name" (Exclude the model number) to your device, in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.
Check and replace its main system control memory IC. It is faulty. Contact any service technician. 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/
If total dead best way is to follow the AC voltage from power cord inside the set to see where voltage is lost.Also , were you having any problems having to turn set on several times to get it on?
It can't be done. The DVD remote will be single frequency for that device only and the LG remote for that LG Blu Ray (or series) only. Companies don't make cross-control between makers easy. The only exception is cable and satellite boxes to allow their remote to also control the television.
If you have lost a remote or it doesn't work, this is the answer
https://www.fixya.com/support/r29872378-universal_remotes_no_facsimile_remote
..
It appears to be a model made for the India market.
https://www.google.com/search?q=lg+dsi+8555+manual
This is the only service manual that is related. If the display is not working, look on the back of the display board for a split or bulging electrolytic capacitor.
Encompass Parts
https://research.encompass.com > ZEN
PDF
This manual was prepared for use only by properly trained audio-video service technicians. When servicing this product, under no circumstances should the ...
109 pages
That will show in your network settings on the tv screen under manual entry network, or automatic entry try both and then write them down when it shows them.
There may be a backlight issue. Some of the LEDs may have failed causing the LED to stop working at the correct voltage. This will tell the main power supply to switch off as there is a problem.
I would ask LG support.
https://www.lg.com/uk/support/contact-us/