[hokieMom]

I have a Samsung Refrigerator with Freezer on the bottom (Model RB1944SL). It's about 5 years old from Sam's Club. Both the refrigerator and freezer stops cooling/freezing after approximately 4 hours. When I unplug the cord and plug it back in, then the compressor kicks in, but it stops working after a few hours. Even then, I can't get it cold enough as it used to be.
The numbers on digital display unit also partially not lit. However, the refrigerator/freezer had worked fine even when the display unit was not entirely working.

I called a repairman who told me the PBA control board and display unit (for obvious reasons) have to be replaced. I fired the repairman after finding out he was charging me more than the double for the parts compared to listed prices on the internet. I'm skeptical that this repairman gave me the correct diagnosis. Please help me diagnose what's wrong with my Samsung RB1944SL. Thank you!