Default Charging problem. USB board dead?

Hello all,

I have a Galaxy S4 (i337) since April 27, 2013; it's been working great...until today. Earlier this afternoon I plugged my phone on the charger because the battery was running low. I noticed that the phone wasn't charging at all...or at least it seemed that way. On the battery section of the Settings app, it stated that the phone wasn't charging, but the percentage kept rising every few minutes. It did the same turned off, on or on TWRP, but the phone kept saying it wasn't plugged in.

Hoping it was a kernel/driver issue with the nightlies I've been running I switched ROMs and even restore from a backup I made a few days ago. Nothing new happened. I kept getting the "not charging" thing. So I unplugged it and the battery started draining quickly, about 10% every 15-20 minutes on standby and light use. So I switched batteries, chargers and nothing.

So, can anyone tell me what's going on here? I already purchased the USB board, but I was wondering if there was an easier solution. I tried cleaning the contacts, but they're not as bad as they could be. So if anyone can shed some light on this issue I'll be very grateful.

Thanks!

Update: This keeps getting weirder. I turned the phone off and plugged it in overnight and this morning the phone fully charged. Although when turned on there's no indication whatsoever of the charger being plugged in. This is frustrating.
Samsung Galaxy S4 With OmniROM nightlies
Google/Asus Nexus 7 (FHD/2013) With OmniROM nightlies

I was an iPhone user for 3+ years, and now I ask myself: "How could I've been so blind?"