headunit problems

[sesterfield]

I have just tried to fit my mum's old cd headunit (CDX-4000R) in my car but it refuses to power up, I've had it going once but when I tried to slide it into place it conked out again.  The tape headunit that came with the car works fine :/

The only thing I've got it to do is make a buzzing noise as if it's trying to eject a CD, and that was when I swapped the yellow and red wires 

Sorry if I'm being vague, any help would be fantastic 

[Len]

First check for any dislogded connections.

[Rain]

sounds like you could have blown it when you shoved it in only way is to try it on your mums car again and see if it works fine there. if it works fine on that when have a closer look at the wiring you may have a loose connection somewhere buzzing isnt a good sign.

[S11EPS]

I'm willing to bet a pound to a pinch of sh!t that you've dislodged a wire and or blown the fuse when sliding the unit back into the dash.

Retrieve it, recheck your connections, and check your fuses. You should be cool and the gang then.

[benjam_in]

check the fuse on the back of the head unit and the one on the live then try it again! oh and check the earth!

[AdamB]

I'd be inclined to agree with S11EPS here. I reckon you may have a stray wire that has earthed out the system and blown something. Re-check your wiring and connections.

[sesterfield]

Well I replaced the fuse on the back and it started working again for a short while, but again when I tried to slide it in it went.  I have replaced that fuse with another but it won't power on again 

I'll check my wiring again, but it seems ok - the wires on the car itself must be OK since the old headunit works fine (which doesn't use the newer wiring harness).

Thanks for all the replies guys it's appreciated

[Rain]

you definitly got a short somewhere

if you got any bare connections tape them up, marks of a short are small burn marks on the cables or the stereo itself.