Akai AM u04 Problem

reben

New Member
Hi

I am new the forum so greetings to all.
I got a Akai AMU04 amp a few days a go from a friend who doesnt use it anymore. Problem is, is that it turns on, all the lights go on so the unit gets power but then nothing else. I connected an Akai turntable, mp3 player via aux ports but nothing. Played around with the buttons maybe something went wrong there but no luck either. Tried different kinds of speaker and also nothing.

So i do not know what to do or where to begin looking what component/s has died or whatever the case may be. The amp overall is still in very good condition cosmetically so dont want to throw it a away just yet.

If anyone can help me i would really appreciate it.
Will give more info on the problem if needed.

Thanks
Reben
 
First make sure the speakers switch (next to the power switch) are on. If there's no sound, check at the back that the jumper between the 'pre-out' and the 'main-in' (left to the speaker connections) is in place. If it's not there and you don't have it, you can use a normal interconnect.

If there's still no sound, try to find out if the problem is in the preamp section or the poweramp section. Do you have another, working amp? Connect a source to the Akai, connect the 'pre-out' to any input (but NOT the phono) on the working amp. Turn the volume on the Akai low, choose the correct input on the Akai and on the working amp and listen for sound, slowly turning up the volume on both amps. If there's sound, the preamp on the Akai is working, if not, the problem is probably in that section.

I suggest you first try the above and let us know how it works out. Good luck!

Edit: petehall347 just beat me. :)
 
Had a look, jumpers are in, speaker buttons are on. I do not have another amp unfortunatly. How can i troubleshoot the preamp and poweramp?

When i turn the unit on i only hear the clicking sound from the power button and then the transormer has a very soft hum. Thought i'd add that random info. Not sure if any other noises were to sound as well.

So what to do next then?

Thanks
Reben
 
Ehmmm... you could try if you get sound connecting a headphone. If that doesn't work... it's hard to diagnose something like that from a distance, so maybe you can find someone with technical knowledge close to you who's willing to take a look.
 
haha yeah gonna take it to someone now. hold thumbs. will let you know what the problem is

Thanks
Reben
 
Is there any relay click ( try it with the speaker switch, A or B, on, because

if no speaker are selected, and then you select A or B, you won't hear the

distinctive click.)

If no relay click, could be a number of things. This amp runs on STK chips..

Have the same one... really worths to make it live again.

Good luck there !
 
just a random suggestion..does it have a volume mute button ? :scratch2: this series of akai had some quirky functions.
 
Pics of mine... no mute... but dust there is
 

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The unit is at the tech guys house and he will let me know tomorrow. I didn't hear any click from the relay. Only sound I hear is the clicking from the power button itself. But I am waiting to hear from the tech. Hopefully it's a quick and cheap fix. Does the knobs have led in them to make them lite up or not? Mine doesn't.

Cheers
Reben
 
The unit is at the tech guys house and he will let me know tomorrow. I didn't hear any click from the relay. Only sound I hear is the clicking from the power button itself. But I am waiting to hear from the tech. Hopefully it's a quick and cheap fix. Does the knobs have led in them to make them lite up or not? Mine doesn't.

Cheers
Reben

They are not lighten up... just a cheap line of green fluo something...

Hope you'll hear a good '' click '' for your tech :thmbsp:
 
Haha okay my bad

Will find out tomorrow

What's the worst case scenario? And how likely could it be?

Worst case would be a dead STK chips that is longer made ( but I don't know if they are still made ). Middle case would be

a power supply failure, couple of resistors failed or a cold solder joint.

best scenario would be some contact or switches that need Deoxit.


Let's make our Karma spirit work... and it will work out fine.

Keep us up to date, will you.

Good luck !
 
Last edited:
Okay so bad news is its the STK 3042 chip thats dead.
Good news is that he is fixing it, just waiting for the required parts.

So another few days and it will hopefully be working 100%

Will you guys posted

Cheers
Reben
 
Okay so bad news is its the STK 3042 chip thats dead.
Good news is that he is fixing it, just waiting for the required parts.

So another few days and it will hopefully be working 100%

Will you guys posted

Cheers
Reben

So, STK's are still available ! That good news for me too !
 
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