2.4ghz WiFi broken, 5ghz Perfect

[euniqe]

Hey everyone,

 

Have a computer that has been running great for almost a year, now. WiFi has always worked well, even 15 metres away from a router up a flight of stairs, through a few walls - was pushing wifi max throughput easy on cable internet (~54Mb/s).

 

However, I have moved to a different place and now all of a sudden my computer does not enjoy operating on a 2.4ghz WiFi network. The internet here is not the best (~13Mb/s) but it is fast enough. It is also very stable on my android phone and all other devices i have connected. However, the PC operates flawlessly on the 5ghz network provided by the same router - the  problem with this being that i am, again, upstairs and through walls so the 5ghz signal is not stable, with either 1 or 0 bars showing. Fine for browsing, bad for MMO's. I need to use the 2.4ghz network for the purpose of stability.

 

I moved the PC downstairs and placed it literally next to the router for testing purposes. It performed perfectly on the 5ghz network, full speed and full signal/completely stable. The 2.4ghz network, however, is able to be connected to and the signal/connection stable (less stable upstairs - was having trouble connecting at all yesterday) but it produces huge lag (300ms and above average pinging to google) and the speed is less than 1Mb/s. I concluded that my computer simply does not operate properly with this router on its 2.4ghz network, which is strange because as I said all other devices function faultlessly.

 

I have also tried using a D-Link usb WiFi dongle to no avail - the results were identical albeit the d-link doesn't operate on 5ghz - so it is fair to assume this is not a hardware problem, even though it may well be.

 

I have also tried changing WiFi channels, am now on an unused channel with only 1 network overlapping but this is irrelevant as symptoms are the same at 4 in the morning with no other networks visible and as I said i put the PC next to the router for best possible connection.

 

TL;DR; internet runs like crap on 2.4ghz WiFi, is a dream on 5ghz WiFi (but need to be near router for stability), changing WiFi hardware on PC end produced 100% similar results, interference doesn't seem to be an issue. Halp pls <3

 

Specs:

Asus Z97i-Plus

Broadcom 802.11ac wireless card (built into motherboard)

Pentium G3258

Silverstone SFX450

Gigabyte 750ti

CM Elite 110 Chassis

Kingston budget/low-profile ram

 

Edit: Just remembered i can test the router-to-pc connection  pinging the router times out on 2.4ghz, get 2ms on 5ghz. Also cannot connect to the router's setup page on 2.4ghz (192.168.1.1) but works fine on 5ghz. So, therefore, it is a local connection issue not an internet issue. Literally no idea how this is possible when 5ghz works 100% fine...

[krkevin]

Contact your ISP or PC manufacturer?

[euniqe]

PC is custom built so manufacturer is irelevent. 

 

As I said ALL other devices work 100%, the problem is with this computer and only this computer. There is nothing the ISP could do to help as the networks are operating normally.