KEF Kube 1 repair

[DistortionNat]

Hi
My kube refuses to power on so I took the amp out and have spotted a component that has burnt out.
Is this a diy job or do I need to send it off?
Any help would be greatly appreciated, I don't have the money to fork out right now so cheap is good

Cheers

Nat.

 

[IronGiant]

I assume you meant KEF Kube, not Key Kube? I've amended the title.

 

[DistortionNat]

Yes thank you! Smartphone fail!!

 

[Frank1471]

You will need to remove it to find its value as (AFAIK) no circuit diagram is available.
It's a capacitor and should be easily replaceable.
Frank

 

[DistortionNat]

Excellent. Also the yellow thing next to it (transformer?) has plastic around it and it looks a little melted. Is this something that could have also gone and should I replace it?

 

[Frank1471]

Looks like a blob of glue sticking the capacitor to the transformer.
Just a word of warning.
These things are quite hazardous to work on. There is 350v DC around this part of the circuit when powered. There could be a residual charge some-time after switching off.
Frank.

 

[DistortionNat]

Yeah not the blob of glue, the yellow wrap around the transformer coil looks kind of melted. I guess it gets hot so maybe just normal.

 

[DistortionNat]

Thanks for the warning and advice I will be careful

 

[spyder viewer]

Transformers get warm and thats just protective tape to prevent the windins from being damaged. As it's a switched mode power supply it will almost certainly be a custom transformer so hard to source a replacement. Pray it's just the cap!

 

[DistortionNat]

OK thank you for all your help. Much appreciated.

 

[spyder viewer]

For what it's worth, that's a polycarbonate cap which don't rate highly in the longevity stakes.

 

[DistortionNat]

OK cool. Well I will replace it this weekend and see how we go.

 

[DistortionNat]

Ok so Ive taken out the blown cap and I have no idea what type it is or anything.
Anyone got any ideas?

 

[DistortionNat]

Only the markings in the pic I posted above

 

[Frank1471]

Assuming the markings are 1uF 250v...
Something like this?

 

[DistortionNat]

Yeah OK. I will see if maplins do one as they are just down the road from me

 

[DistortionNat]

Would this do?
Metallised Polyester Film 1uF Capacitor | Maplin

 

[spyder viewer]

If it is agreed that 250 is the voltage rating, then definitely not!

 

[DistortionNat]

oh yeah!

 

[DistortionNat]

I ordered that cap that you suggested, soldered it in today. Bingo! It works, my sub works and you saved me I would have thought around £80.
Thankyou!!

 

[keithwarr]

hi i had the same problem and followed you and soldered in the same part but light comes on but no sound does it make a difference which way round it goes in

regards keith

 

[DistortionNat]

Hmm not sure. If the light comes then I would have thought it was the right way round. I can't comment really because I don't know why you would have no sound. Mine just worked.

 

[keithwarr]

Hmm not sure. If the light comes then I would have thought it was the right way round. I can't comment really because I don't know why you would have no sound. Mine just worked.

opps dropped a b*llock the part that has burnt out is the small black component th502 i soldered in the part you have replaced the standbye light comes on but my dad in law says he gets no sound what is the replacement for th502
regards keith

 

[spyder viewer]

We aren't the Kef service department but our members will help all we can. The board markings mean little to me. Do you have a photo? Why do you think this is the problem?

Polarised components are usually marked accordingly, ether with + or a solid line with a broken line along side.

Welcome to AVForums

 

[Frank1471]

opps dropped a b*llock the part that has burnt out is the small black component th502 i soldered in the part you have replaced the standbye light comes on but my dad in law says he gets no sound what is the replacement for th502
regards keith

Have a look here:
http://lug.demon.co.uk/kefrepair/?p=136
Frank.