Not sure what colour buttons should be illuminated when working

freezer section not working
get a fridge technician in to check / repair.

are you sure its condensation and not water flowing over the top due to being unlevel, or pan cracked

High back pressure is generally a sign that the evaporator coil is clogged with debries or the fan isn't working I suggest checking this first.

Maybe there was something bumped or overlooked during the cleaning/repair process like a cooling fan?
Did you add any other appliances to that circuit before/after/during the repair to increase amperage draw on the breaker?
Try replacing the overload protection outlet with a new one as it may be faulty/worn out. Good luck

Here is my video how I replaced evaporator on undercounter refrigerator.

First, I'm not a Neff representative.
* Check your warranty. Call for support.https://www.neff-home.com/uk/service/support
* Website; https://www.neff-home.com/uk/products/fridges-freezers/fridges
* Manual (official - requires you to register.); https://www.neff-home.com/ie/service/manual

*** The following is for information only.***
* Model needed for specific solution.
* The buttons are for setting the coldness (harder?)
* There are some models that can change the chill "box" section to a freezer.
* Product specs (Official); https://www.neff-home.com/uk/products/fridges-freezers
* Neff Integrated Fridge Freezer K8524X8GB Product Overview (check 0:35) ; https://www.youtube.com/watch?v=NVqMz7cbY4o
* Neff K5920L0GB Side By Side American Fridge Freezer; https://www.youtube.com/watch?v=92ugO2ArjaA
* Neff KA3902B20G Side-by-side fridge-freezer; https://www.ruislipappliances.com/images/PDF/KA3902B20G.pdf
* Catalogs; http://pdf.archiexpo.com/pdf/neff-9796.html
* Products; http://www.jamesratfordbridge.co.uk/downloads/Neff_brochure.pdf
* NEFF KI2823F30G Built In Fridge;http://www.creativelivingni.co.uk/neff9.pdf
* use the posted contacts for specific support.
Aloha, ukeboy57

Hi debbie. Before you hire any repair man please price a new one. The new ones run on 1/6th the electric as the old and they are often under $200. Check them at Home Depot or lowes, even KMart which now handles the Kenmore/searss line. I believe you will end up replacing as opposed to repairing.

evaporator coils is probably frosted from condinsation.shut door set at normal setting and give some time.

Loosen the top hinge screws.
Pull up on the door to where you want it.
While holding the door in place, re-tighten the screws.

Coils are probably underneath. remove the grille at the front (usually you just rotate it down to pull off) and then vaccum inside with a wand. If there aren't any coils there either, pull the machine out from the wall, and remove the lower panel from the back side. Inside you should find a fan next to a coil. Make sure that fan is working, and if it isn't make sure it is getting power.

Vacuum out as good as you can, and if you can use compressed air to blow it clean, even better (vacuum first because it will kick out a lot of dust).

If vacuuming the coils doesn't work, then you probably have a freon leakage problem, in which case it is probably not worth the cost of repair.