TV won't turn on

So my model number is actually rled4627a

And it won't turn on upon plugging it in after waiting some time ill get the red light that there's power

When I try to turn it on I get the green light then immediate power down. No red light unless I unplug and wait 10 mins

Now before it just wouldn't turn on for the past 4 months or so upon start up it would turn of and on about 4-5 times before powering up.

I've removed the back panel to check the power supply im equipped with a multi meter but totally lost wonder how to check the capicotors and maybe sodder a new on in any help would be great repair shop wants 90 dollars for diagnostic a new tv at Walmart is like 260 anyway