Backlight went out, replaced power board, made it worse.

So I got a clearance 50” Vizio 4k Smart D Series TV from a Walmart. It was one of the wall displays so I got it for SUPER cheap. I had it running for 3 weeks with no issue and then it started flickering. Eventually, the backlight went out completely and I read to replace the power board so I ordered one off shopjimmy.com. Except hey didn’t have only the power board so I ended up having to order the power board, inverter, and AV connection board. However, the inverter board was NOT the correct board even though I know it was for the exact model of my TV which I am going to have to call them for. Anyway moving on…

It came in, I replaced the power board and the TV turned on… for 10 minutes and then the backlight went out again.

Here are some observations I made while troubleshooting and trying to figure it out on my own:

• After a power cycle, when I turn the TV on the power light on the TV flashes once and then comes on then goes into the second point here:
• When turning on the TV, the LED light indicator comes on and then slowly fades off.

Any input into the matter would be really helpful. I’m between jobs right now so money is kinda tight and I can’t afford a new TV at the moment.