Fridge from Hell

[thxyung]

This is Samsung side by side with dual evaporators. First the freezer would warm and the fridge side would freeze things. Removed both covers and both sides had ice build up on coils. No errors from the diagnostics. Seems like defrost issue, but could both def heaters go out at same time? Replaced the computer as this affected both sides. Now the fridge works fine, but the freezer side doesnt cool but to around 28-35 or so. Coils are not frosted up, but there was some ice on the freon lines, but not blocking air flow. Even after taking off the ice, the fridge takes like 8-12 hours to cool down to 0, but then goes up to high 20’s or mid 30’s. Condenser fan working and coils are clean. I replaced the temp sensor and thermostat in freezer section and same prob. Need some guidance on this. Cant afford monster bill. Please help.