It just won't turn on! i've plugged it into the mains, and connected it up with my guitar and amp but the red light won't come on and won't make any noise.. i only just bought it, so have never used it so might be setting it up wrong. thanks

1- check the outlet for power by plugging in a lamp or something
2- check the amps fuse. Most power amps have user replaceable glass fuses.

Have you checked a different cable?. Also, when you plug in the unit, there should be a "pop" if everything is turned on. If there isn't, the connection is bad someplace.

Check the power supply voltage and look for a hot component. If it takes a while to bring on the symptom it's probably something getting hot.

How new is the amp?

A single faulty solder can do that...I'd try returning in to the seller.
Have you tried a different amp with the same equipment?

Sounds like a wiring issue.

Hope I've helped
PvT

All amplifiers make a little bit of noise (hiss) but it is normally slight and drowned out by playing. However, assuming that this is not normal system hiss, here are a few simple steps to try and locate the source of the problem by process of elimination.

1. SAFETY FIRST - a common cause of a humming or buzzing sound can be a lack of earth (grounding) on the mains supply. With a 240volt AC supply this hum will be at 50hz (in the UK) - frequency may vary in other countries but should be similar. Check the earth first because of risk of electric shock. Until you are satisfied that this is not the cause of the problem DO NOT touch any metal parts of the amp. Remove the mains lead and try a different one. Try plugging the amp into a different mains outlet socket (preferably one on a completely different circuit).
2. Turn off other electrical equipment in the vicinity that may be causing interference. Move the amp a bit, try rotating it by 90 degrees to change relationship to things like mains electric cables in the floor.
3. If you are using the line-out socket to give a feed to a mixer, slave amp or p.a. system unplug this. Sometimes double earthing (through the mains lead of your amp AND the mains lead of the MIXER / PA) will cause an 'earth loop' due to a different resistance at each end. Putting a DI box with an 'earth lift' in between may eliminate this problem. Alternatively there are little gadgets you can buy to do this (I found one intended for car audio systems on Amazon that works very well)
4. Unplug any instrument leads - to eliminate possibilities of interference affecting cables, effects pedals or guitar pick-ups. Also unplug the foot-switch.
5. If that stops it plug a lead in without a guitar on the other end - does the noise return? If yes change the lead. If no plug the guitar in.
6. Try moving the guitar in relation to the amp (turn it around 90 or 180 degrees) - this will be pick-up to amp power supply interference.
7. Does the sound get better or worse if you touch metal parts of the guitar with your hand? This may be a screening issue within the lead or the guitar itself.
8. Try turning all the individual channel tone and gain controls to zero, turn off any effects on the amp panel. If that eliminates it only turn up the controls on channels that you are actually using.

Test the amp cable by plugging in the guitar cable an touching the end of the cord and you should get hum from the amp if the volume controls are up.

Many guitars require a battery to operate the preamp inside them.. Verify if yours needs a battery and it is fresh and properly installed.

These batteries are turned on by plugging in the guitar cable into the guitar. Leaving the cable in will exhaaust the battery, often within a day.

You would NOT use a stereo cable to plug in your guitar.

The stereo cable would carry the battery voltage back to the amp and MAYBE cause the fuse to blow.

You use a MONO instrument cable for your guitar.

The ring connection is use to complete the circuit to turn on the battery in most guitars.

Replace the fuse ONCE and get the proper instrument cable (NOT consumer audio cable) for your guitar.

If fuse blows again, take amp to shop for service.

Here are some things to check:
- Are all volume controls turned up 1/2-way? - Try a different guitar patch cable. - Does your amp have remote switchable inputs? Is your guitar plugged into the *active* channel on the amp? - Is the amp turned on?

the buzzing is indicative of an open ground connection, check the cord by substitution or with an ohm meter, if the cord is good look at the connections to the jack inside the amp ( im guessing you built the amp from a kit). Is this a solid state amplifier? Tube amps have lethal votages and should not be experimented on without knowledge of electronic safety. Also if there is more than one input to the amp try plugging the guitar into another one and see if its still the same.