Need advice on a faulty c audio ra3001!!

[dean ashmore]

I have not long bought a ra3001 off the net, only used it twice, blown fuses both times!! First time it blew the external fuse, 2nd time tried to use it blew the first internal fuse on the left half of amp as you look at the front of amp (T1.6AL) The amp appears to have had couple of the components replaced before. Could do with chatting with someone who knows these amps well as would like to fix it rather than replace. cheers

[burbeck]

hi Dean,
we have a c-audio expert here on this forum, do a search for Lee Basham mabye drop him an email

[krmaudio]

hello,

sounds like the large 50w aluminium gold coloured soft start resistor on the chassis has gone open circuit.

its used to stop mains inrush at switch on.

if the resistor goes open circuit, the T1.6 fuse usually blows, (this fuse must be replaced with exact type and size)!

the softstart resistor is usually 47ohm, its a fairly easy fix, bear in mind the resistor passes raw mains voltage......

but replacing it should do the trick..............

good luck

[krmaudio]

soft start resistor on the RA3001 could be long white coloured ceramic version, its probably mounted directly on circuit board and soldered directly to pcb tracks.

its a bit hard to get the exact same ceramic version these days, so usually the aluminium clad version gets retro fitted and remotely mounted with flying leads to board....

think the RA3000 had the aluminium version....

[dean ashmore]

Thanks for the advise guys, shall have a go at it.! Another query, if anyoneknows!!!! what are the black components in middle of the amp?, they have three terminals and have the codes k1058 on them, these then have other codes varying as follows, 4d3, 4f3. One of them has been changed and is soldered with two of the pins crossing over, the code on this one is different, 6k3. Does this sound right?? Would appreciate anyones thoughts! Cheers

[krmaudio]

These are the output transistors, k1058 and j162 +/-

the codes you refer to are the date codes (when they were made)

sounds like one or possibly more have been changed....

was it an ebay special? lots of people dump faulty or badly repaired gear on ebay, a bargain isnt always so......

not sure what you mean by legs crossing over? maybe a pic would help?

best

karl

[burbeck]

hi
i agree the soft start circuit 'balast' resistor may have failed on this amp,

i think you have more problems as well. especialy when you say the external fuse also blown once.

i dont like the sound of the part with the crossed over leads as krm says pic would help,

most important thing make sure the fuses are of the correct type and bear in mind you are working on mains power

[dean ashmore]

Thanks again for the advice, not gonna try anything until definately know what i'm doing!! Here's a pic of the component with the terminals crossed! may need to zoom in to see clearly, its the dodgy looking one with the white stuff underneath!! Not been able to get decent closer pic, sorry.

[dean ashmore]

Behold (somehow managed to send last message without this!!!)

[dean ashmore]

Sorry, just realised that file size too big to attatch to this!! Am not full verified user yet of this site so can't email it to anyone. Will do when can if that is cool?