The symptoms are that the remote seems to fire OK. When i point the remote at a TV receiver just for test purposes, I can see a red LED flashing on the receiver set but when pointing the remote towards the Xbox receiver there is no response to any button presses.
So a while ago i dismantled the remote and connected the Infrared output to a Oscilloscope. The signal coming
from the scope was a particularly noisy pulse train so i suspected the decoupling was poor on the PCB.
The addition of a small surface mount capacitor close to the power pin where the battery voltage is supplied to the IC
cures the problem. You can salvage the capacitor from an old phone OR USB stick as per my example.
You can see the supplement capacitor in the photo below. It is stood vertically of the Power pin of the IC. The additional green wire is connected to 0V (Ground) on the PCB.
I think the real problem lies with the poor choice of decoupling capacitors. The Xbox remote control has only
an Electrolytic which is prone to leaking and also not positioned close enough to the IC due to the mechanical nature of the assembly being a single sided PCB.
So here are my steps for fixing the remote OR you can watch on youtube
Note, this fix may well work for other remote controls which have poor decoupling OR leaky capacitors.