Hi. I commented that chassis is thus to guide me to help you.
If the horizontal does not oscillate, it will not have flyback output voltages such as vertical.
You must control the power to the driver transformer. In ST mode and when it gives PW. Placing the tester in st and do not remove it and from PW.
Check if the + b is reaching the TSH manifold, but in st.
Check jungle tension Hvcc. For the doubts in ST and when giving PW. The same in the Hout pin which is where the pulse comes from at the base of the hirizontal driver transistor. You must have the tension in your collector in ST. When I comment chassis it will be more
Specific. Check the buttons that work well. Pressing should dial 0. PW is given with that of the channel. NO of the volume or menu. These must be powered with 5v. PW with remote control. Do not touch anything else on the vertical cinculto.
Is the MC-83C series printed on the main card?
Please make sure the Chassis so you can be sure and give accurate information.
By saying "I think" we all remain in doubt
Diagram here:
https://www.electronica-pt.com/esquema/tv/lg-esquemas-tv/lg-tv-chassis-mc-83c-2524/
Excuse me, the suggestion is not to measure in the TSH, but in the collector of the horizontal DRIVER transistor.
Test directly on the Power pin of the microprocessor, if there are changes of Voltages in both STAND BY and the ON order.
Heat the chips or pins on the Microprocessor's swing glass and repeat the test
I heated the legs of the microprocessor's oscillation crystal, repeated the test and everything continued the same. I measured the voltage in the collector of the horizontal driver transistor and it gives me 13V. When I press power everything stays the same in ST because it is like the TV does not recognize that it is being sent to turn on.
The working conditions of the microprocessor are
Microprocessor and EEPROM voltage.
RESET voltage
Voltage on the microprocessor crystal pins and the good condition of the crystal.
Check the good condition of the command buttons on the front panel. And the power (voltage) of them
Thank you very much for spending time trying to help me, in the end I didn't know how to fix the TV and I gave it back to the owner. I think the problem was in the microprocessor, but I didn't have any available to replace it. Really, thank you very much for the suggestions.