Amplifier problem..

[jamiepyrite]

Hi all, so I own a 1.4 seat ibiza mk2. Been using a Toxic T500 2 channel amp with a kenwood sub and JBL rears (front speakers are powered by head unit)

Anyway, I took the amp and everything out a few weeks ago. Installed them back in and they won't work! While un-installing, I got a spark from the switch cable while unscrewing it. (Thought I'd unplugged the live.. Guess I hadn't!) Which blew the fuse on the amp. I would have thought that any surges that it could have caused would have been saved by the fuse (hence having one). Well, the amp won't work. It has a green light for power and red for protection and the red light is showing every time.

Some things I have tried:

Unplugging everything, plugging back in.
Checking everything is plugged in properly.
Moved the ground to a different area (it is on bare metal)
Swapped the speaker cables into the amp around incase I had put neg into pos. etc.
Removing and inserting the fuse while turned on. Told this could reset the protection but to no avail.
Replaced the (15A) fuse.
Used a 20A fuse instead.
Tried knocking the head unit's volume all the way off before turning it on.
The volume on the amp is at half.
Tried unplugging all the connections that lead to the speakers.

And nothing!


Any ideas please? This has me stumped!


Cheers

 

[ScotlandToIbiza]

I'v got the same problem just now, good to see what replys you get.. I havent replaced the fuses yet but I got a wire brush to the connectors (being a bit old and rusty looking ) but no joy!

The green light is still on, all I can think of is when i was unscrewing the power lead and it started sparking.

 

[thewiizard]

check the fuses first of all, if they're all ok, get the multimeter out

 

[jamiepyrite]

Heh, yeah it's always best ti just disconnect the battery first.. Thought I had but I guess I hadn't!

I suggest trying all the things in my list Are the speakers definately wired up the right way round too? Common error.

 

[jamiepyrite]

wiizard: What exactly what I be doing with the multi-meter? Like where would I be checking, etc. ?

 

[ScotlandToIbiza]

think all connections?

Have checked the speakers a thousand times lol there ok! first time I checked they were the wrong way around due to the guy at the local shop who helped me wire it up

 

[surcalation]

have you checked the earth? is it bad?

 

[thewiizard]

Yeah check you have a good return earth to your battery, if you have a nasty rusting crap of a chassis then continuity is lost and the current will not travel as it should but i doubt this is the case.

9/10 its a blown fuse, either under your bonnet if you have a 40/60a glass fuse or on the amp, should have 2 x fuses, maybe two 20amps or two 30s for example.

Get the multimeter on the amp. Set it to 20V+(or similar) and then black probe on negative side, red probe on positive side and see if you get a reading. If not, check the fuse

Check the earth from the amp to the chassis by switching the multimeter to 'beep mode'. Touch one probe on the negative side of the amp and the other probe onto the chassis, you should get a beep to indicate you have a connection.

If you still get nothing then you should consider contacting a sparky or a mate that has a sparkies head

 

[jamiepyrite]

Right cheers for that! Thats on the joblist for tomorrow including cleaning the interior!

I shall report back tomorrow with my findings

 

[Dolly_Gti]

maybe the red light on the amp signifies its been overloaded. and maybe there is a way of reseting the amp? small button that u stick a pin in or summat saft like that.

 

[Czechboy]

If you had a bad earth, none of your lights would light up. If you blew up the amp, none of the lights would light up. Red means the amp is overloaded. Now you need to find out why you amp thinks its being overloaded. Switch off the power and remove the fuse so the amp can reset itself. Then disconnect all the speaker wires that come into the amp, and also disconnect all the phono leads. So that its just the Live, Ground and Remote Live that are wired up. Now see if you still get a red.

Mig

 

[surcalation]

Mig, red light comes on if you have a bad earth connection. To tell you it won't do anything because you have a bad earth. That's what an old amp of mine would do. If it wasn't earthed properly the red light would come on. Red meant "protection mode"

 

[Czechboy]

But if you have no earth, you have no closed circuit. Therefore current cannot flow. And with no current flow, there is no electricity to light up the LED.

Unless that is only if you have crappy earth, so that enough current can flow to light up the LED, but once you try powering up the speakers, the earth isn't sufficient and the amp overloads and LED lights up red.

 

[Rosc0PColtrane]

Check the earth. Hell of a difference between bad earth and short circuit.

Bad earth will have a greater volts drop, higher resistance, IIRC. The amp may be picking this up.

My thoughts were to find a reset button on the amp. Check all fuses. Check manufacturers website, check owners manual, they usually have a troubleshooting section. Make sure the fuses you have replaced are of the correct rating. A simple mistake to make.

 

[jamiepyrite]

Unfortunately, there was no instruction manual provided.. and it seems as the website has dissapeared! I've tried searching for it but nothing came up - Then I found a link to the official website from an online ICE shop but that was a dead link..


The ground I was using since I got the amp, etc. was a screw that the NS lights were grounded to. This worked fine until I took the amp out and put it back in. So I tried a different screw going into metal (I think this one was to hold the bumper on or something.. But it was connected to bare metal. And that didn't work either.

Shall get the multi-meter out now

 

[Czechboy]

Unfortunately, there was no instruction manual provided.. and it seems as the website has dissapeared! I've tried searching for it but nothing came up - Then I found a link to the official website from an online ICE shop but that was a dead link..

Just search the web for FAQ of a different make amp then. As most amps these days use the red/green LED protection thing, and most will work in a very similar manner. So if you look at the Trouble shooter section of one amp, chances are it will be pretty much identical to your amp as well.

Mig

 

[thewiizard]

The ground I was using since I got the amp, etc. was a screw that the NS lights were grounded to

Personally i always use the seat be;t mountings for a couple of reasons.

1) Is so that the large drain doesn't effect the earthing for anything else, such as lights

2) To try and ensure the best possible ground available, my theory is seeing as seatbelts brackets are seem welded to the chassis, these should provide un-contended continuity.

 

[jamiepyrite]

I'll try mounting it to that then What would be the best way to mount it as it's just a metal ring on the end which isn't that big. Soldering it to the seatbelt mounting?

 

[thewiizard]

Hmm, may seem a bit bodge like but strip about an inch/inch and a half of wire off... split the wires into two bunches then simply wind them around the thread of the bolt, then when you crank the bolt back in the wires will get spread underneath the bracket and should get you a nice contact

You could always go out and buy a nice connection plate type object of some kind and design.

 

[jamiepyrite]

Hmm, I've just checked the ground I've been using with the multimeter and it gives a good reading so I can't see it being that.

Just taken the cover off the amp and checking various bits and bobs of the circuit board. Everything I tried is giving me a reading so I can't understand why it won't work! I'll do a bit more googling around to see what I can find..