Does the Input LED light up when you play something on the guitar?
If not, i would think about a replacement unit from the place where you bought yours. Never heard of a defective input jack before, but it seems like the jack is broken from what i read.
Are you sure you're using the input and not the headphones out??? Input is the jack to the right. Happened to me a few times and I'm sure to others as well.
I've done this once, and it was when I demod the unit to the most awesome chick I've ever met.
Classic. She just wanted to play Metallica!
Ive emailed Kemper support maybe they can think of something
They will surely help you in this case, but i would prefer to get the unit changed at the store where you bought it. Should be faster.
just an update
Kemper support suggested a system reset which i did
unfortunately it didnt fix the problem 
The alternative input works because it has a TRS jack, used for returning balanced signals. That's why a higher noise level is acceptable - a balanced signal will provide a cleaner signal to start with. The front input does NOT work because it has a TS jack, as it is designed for a guitar input.
The ring (R of the TRS) would meet where the sleeve is on a TS jack, causing a short. This might work for some equipment, but it simply doesn't for others.
In short, use a proper instrument cable. Why buy a $2000+ unit and try to use cables that weren't even designed for the instrument you use/
Display MoreMy first suggestion is the common RTFM comment: read the manual. Both the basic "getting started" one and the "reference" manual, available online. For now, focus on the output settings. The manuals are easy to read and provide insight of every feature and function of the Kemper.
I'm thinking there are several issues going on here.
When you play through either input (with the setting for which input you are using properly configured), does the "output" light (the little green one above the soft button) illuminate? If it does, it's a problem with your connections going out from the amp. -Infinity means zero volume, which is why you aren't getting volume on your headphones out. Try turning this up and seeing if you're hearing output. You also have two volume knobs on the unit - a "master," which can control whatever you tie it to - main out, headphone out, monitor out, whatever - but you have to "link" them to the master volume control. This is why turning that knob adjusts that volume. The other volume knob is the volume for the current rig you are on. You may have turned this completely down and not realized it.
When you play through either input (with the setting for which input you are using properly configured), does the "input" light (the little green one above the soft button) illuminate? If it doesn't, it's a problem with your connections. Try a different guitar cable, and, if you're running pedals, try bypassing all of them. Otherwise, check the input settings - make sure things like clean sense and distortion sense are at 0. You can tweak these later.
As far as your outputs are concerned, TS = tip/sleeve, a.k.a. a mono guitar cable; TRS = tip/ring/sleeve, a.k.a. a balanced cable or a stereo cable (think headphones). You should NOT be using TRS cables to output anything, as all of the outputs on the back are single channel. You're effectively shorting out whatever power amp you're driving by using TRS cables on the main outs.
Also, if you're using a mono speaker setup, you want to use the monitor out instead. Try using that with a TS cable. THEN adjust your monitor volume from the output settings. You can link the monitor out's volume control to the master volume knob at a later time; for now, we need to get you sound.
Finally, have you tried browsing through the rigs? The rig you are on may be muted by some effect parameter or volume control. Try a different rig.
Great troubleshooting approach, Doug.
Hi dougc84
As per my post to you "with the guitar plugged into the front input jack the output and input light does not illuminate and i dont hear the rig"
so no, its not registering any activity from the input jack.
Interesting about the TRS/TS jacks. Ive been using this set up for 6 years running it thru an Axefx, pod hd500x, various VOX and digitech products and never had an issue using the existing cabling. Anyway I appreciate you trying to help me Thanks
It sounds to me as if you dismissed the connector "mismatch", in your mind at least, as being a possible cause of your issue, Joe.
At this point I'd bet my house, if indeed I owned one, that there's nothing wrong with your unit. That would be a great thing, of course, as I too am in Oz and appreciate how bloody long we have to wait for everything!
Doh!
Just confirmed, scary yes, but in the interest of helping Aussiejoe a TRS cable does work with sound in the front input jack. HTH, and no I use a TS cable 
Looking like he has an input jack problem as that input light should show some activity when he strums the guitar.
Yeah, I did get you, Joe, as evidenced by my reply earlier:
HI dougc84
Im using a standard guitar cable for input to the Kemper
The TRS cable is the cable between the speakers and the amp.
XLR one end TRS the other.
cheers
Doh!
Lucky I didn't have that house to bet, eh? LOL
Only thing I can think of is something in the settings that's prioritising the aux input over the front one... a reamp setting? Not sure if you've explored this yet, or even if the reset would've wiped the pref... but thought I'd mention it nevertheless.
Fingers crossed for you, mate... I mean, AussieJoe,
AussieNicky
I think factory reset would have put it back to plug & play like Kemper wants it when a user receives it. Less support tickets / calls. If you got it from a local shop, I'm with Chruschdy and I'd take it back there first and have it replaced.
If this is a hardware issue, the only thing that will fix it will be a replacement or repair.
If you bought it new from a dealer with inventory, replacing it is the fastest solution. Otherwise, stay in contact with Kemper Support, and don't attempt ANY fixes, unless they tell you to do it.
Understood - with dealer availability in mind, Kemper Support will likely provide the fastest solution.
Ok, let's sum a few things up:
1. Front input is TS unbalanced
2. Alternative input is TRS balanced
3. Main Outs are XLR balanced or TS unbalanced
I can't argue technically but I have the strong feeling that your issue has to do with the TRS-XLR cables from the main outs to your monitors and some kind of circuit between the front/alternative input, the used cables und the main outs. I'd simply buy or borrow two TS-XLR cables and see what happens.
