Let's discuss circuit boards in refrigerators for a moment, please?
This subject is often overlooked by the do-it-yourself refrigerator repair gurus. Unfortunately, simplified advice for circuit board repairs is just non-existent. If the board is damaged it needs to be replaced, unless you are part of the 0.0001% with expert experience to physically repair the board.
That said, you cannot just blame any issue on the control board. Some indication needs to exist that the board is defective and causing issues within the fridge. Otherwise, by replacing this layer you might not achieve anything - as the issue could only affect parts at the surface level.
We will help you understand how to diagnose a fridge that won't turn on, specifically in cases where the circuit board is to blame for that. So, to get started: Unplug / kill power to your refrigerator:
Take off any casing and obtain access to your fridge's circuit board. Check for any burn spots which will be an obvious tell that the board is damaged and must be replaced. Next, plug in the fridge with it taken apart as-is and tap the compressor relay: Replace the board if the refrigerator turns on at this point.
To replace, transfer press-on connectors from one board to the other and push every connector onto the appropriate header pins and, voila, you're done. This job isn't as hard as it seems!
Fridge circuit boards can get pricey, but it depends on your model. The biggest detracting factor is the possibility that replacing the board won't fix the issue. However, you must remember that - even without any burnt spots - the board could be defective. There's two sides to every story; if you replace everything else, while your board is defective, eventually you'll replace that too.
Wondering whether you should repair or replace your refrigerator? This decision comes down to your personal and financial situation. If you cannot afford to replace the unit, all you can do is pay for the repair and hope it lasts a long time. But, those that are financially able to should consider the cost-effectiveness of repairing versus replacing. Look at how old the appliance already is and how much a repair would cost as compared to a new unit. Around 30% is a healthy threshold but, if the appliance is super new, you might be willing to pay even more.