Thanks, which board is the main digital board? Is it the power board that the power cord plugs into?

you could do a force back light test .
Remove power cord, remove 1 side of the cable going between the main board and Power board. Plug in power cord and see if you get back light. The light should be on FULL since the main board is removed from the equation.

If backlight is fully bright then it could be the main board causing the problem. Any time you cant see main menu of the TV it also could be main board problem,

If you do force backlight test and the LED still do not look like htey are firing then it could be Power board or LEDs themselves.
Check voltage on CN802 and CNI801, proper low voltage should be listed there
Also CN201 pin 14 should be 1v-4v -> thats the diming signal

Sustain board fault. If you wish to get some details; check the site linked here. Pull up older posts. http://electronicshelponline.blogspot.com/

does your plug have a reset on it?

This is a common problem for your GSL25JFR . It is very likely a defective=> WR55X10942 Main Control Board Usally when this happens the start relay, overload and run capacitor are also changed when replacing the WR55X10942 Main Control Board. I'm here should you want my assistance,Thanks, John Tripp Appliance 911
Contact Me Here

The power supply board is at fault. You have a shorted diode. Location of this diode is D639. Replace it with an NTE 5087A. The board you will fix, has the power AC cord attached to it! Thanks for asking, Matt of Martins TV.

A loud hum could be caused by an Earth loop. This is caused by connecting various stereo equipment into different mains power outlets.
To overcome this problem, use a power board and plug all the stereo equipment into this single power board.

If you are comfortable with working in tv circuit boards then unplug tv from AC wall socket, take off back of tv and follow AC cord going inside tv that will take you to power supply board, check fuse on power supply board, replace it with same rating written on it if it found blown.
Replug tv back in wall socket and check if it turns On.
If still problem not solved then power supply board is defective and need to be replaced.
Local tv repair shop will help you if you think its not safe for you to work inside tv.
Hope these info will help you.
Thanks.

Hi


Thanks for using FixYa. From what you have described it seems the issue is with the power board or the main board we’ll need to check few things. When you open the unit up; take a look at the power board-the board where, the power cords/plugs goes into. You might see some filter capacitors a little bulged up in the top-If this is the case-this is your defective part(you can try to replace them-but some soldering equipment is needed). If not, then probably the main board has gone bad. This is the other board-where all he inputs are going into. Also check for the Backlight Inverter Board if the sound is coming fine from the TV however as its shutting off so it should be either the power board or the main board. All this is only recommended if you have electrical expertise and know how to solder/re-solder components. . Please do accept the solution if the issue is resolved or else revert for further assistance.


Thanks
Rylee

If the mains cord has only 2 pin plug, you can plug it the other way to see if the mains cord has an open circuit at one of the wires. It is not uncommon to find open circuited mains cord for a large appliance like a TV. The degaussing circuit causes a surge in current consumption when you switch on the TV from cold.

I'm an engineer for Hyatt hotels and I've worked with the S12 vacuums for a few years now. The most common problem electrically lies in the main switch and the power cord. Almost at no time in the past three years and working for 4 hotels have I had to replace any motor or board component for them. Take out the handle from the bag housing and use your volt meter/circuit tester to test the main switch, if that and your power cord are good, then you might have a bad fuse, which is located on the brush side of the main chip board. Any other questions, feel free to email me directly @ [email protected]