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
hi Dean,
we have a c-audio expert here on this forum, do a search for Lee Basham mabye drop him an email
we have a c-audio expert here on this forum, do a search for Lee Basham mabye drop him an email
soft start
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
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
and to add
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....
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....
ra3001
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
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
o/ps
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
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
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
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
ra3001
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.
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.
ra3001, pic of dodgy looking component with crossed over terminals!!!
Behold (somehow managed to send last message without this!!!)
Behold (somehow managed to send last message without this!!!)
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?
Reduce the photo using MSpaint to a smaller size and save as a .jpg
It should then be possible to upload it.
Andy
It should then be possible to upload it.
Andy
Thanks for the tips on picture sizing, if i did it right here goes....As you can see the middle component has had the connections cut and crossed over, it the only one like it on the amp and has a slightly different code to any others, the component on the left has also had a connection cut and soldered, as have few others but these all appear fine and is only on one of the three connections on each component. The component on the right looks how i imagine a normal component to look like! ! ! !
The amp was off ebay, seller said he had recently fitted new fan to amp! Looked o.k buy from description....... Got it because use another c audio amp which gets cranked up regularly and has never faultered....
The amp was off ebay, seller said he had recently fitted new fan to amp! Looked o.k buy from description....... Got it because use another c audio amp which gets cranked up regularly and has never faultered....
Attachments
ouch
well a bodge of epic proportions.....
i assume they all have the same part number? 1058?
i would guess the tracks under the circuit board are burnt and there has been a slight re alignment of the component tracks, maybe a good idea to turn the amplifier over and check under the transistor, see if the track side is burnt......
you can usually tell more about an amp if you look at the copper track side of the board, a whole host of previous bodges usually show up.....
like i said ebay can often be crap bay........
did you get any thumping noise through speakers?
can you measure any dc at speaker terminals?
well a bodge of epic proportions.....
i assume they all have the same part number? 1058?
i would guess the tracks under the circuit board are burnt and there has been a slight re alignment of the component tracks, maybe a good idea to turn the amplifier over and check under the transistor, see if the track side is burnt......
you can usually tell more about an amp if you look at the copper track side of the board, a whole host of previous bodges usually show up.....
like i said ebay can often be crap bay........
did you get any thumping noise through speakers?
can you measure any dc at speaker terminals?
Hi, will open bottom of amp and have a look!!
Can't remember if heard any thumping through speakers, used to power two subs with 400w collosus speakers, ran for about 20 mins then died!!!
Have run out of t1.6a fuses, need to get a few and start plugging it in and see what happens!!
Incedentally the subs not long after blew up and need reconing i guess, they have siezed!!
Do you know much about speakers?? Got a crackley wharfedale pro lx12 that is really annoying, can't use it until sorted! (obviously) Another ebay special i'm afraid, was like it when got it, thought would fix it cos got them for good price, replaced hf diaphragm, still no better!!
I'm accumulating loads of stuff that is broken or breaking!
Can't remember if heard any thumping through speakers, used to power two subs with 400w collosus speakers, ran for about 20 mins then died!!!
Have run out of t1.6a fuses, need to get a few and start plugging it in and see what happens!!
Incedentally the subs not long after blew up and need reconing i guess, they have siezed!!
Do you know much about speakers?? Got a crackley wharfedale pro lx12 that is really annoying, can't use it until sorted! (obviously) Another ebay special i'm afraid, was like it when got it, thought would fix it cos got them for good price, replaced hf diaphragm, still no better!!
I'm accumulating loads of stuff that is broken or breaking!
ouch
sounds like lots of dc voltage at outputs, maybe check the two relays near the fan see if contacts are burnt or welded together....
if you have or can borrow a multimeter, check for raw dc voltage at the output binding posts of the amp, a healthy amp should show between 0 and 30 mv dc at outputs, not really anymore....
if there is anything like 70 volts or more across binding posts them amp has lots of dead output transistors.......
bit of advice...... treat almost everything on ebay as suspect!
sounds like lots of dc voltage at outputs, maybe check the two relays near the fan see if contacts are burnt or welded together....
if you have or can borrow a multimeter, check for raw dc voltage at the output binding posts of the amp, a healthy amp should show between 0 and 30 mv dc at outputs, not really anymore....
if there is anything like 70 volts or more across binding posts them amp has lots of dead output transistors.......
bit of advice...... treat almost everything on ebay as suspect!
ra 3001 schematics
Hi, if by any chance somebody could supply me with schematics for a c audio ra3001, would be greatly appreciated!! Just found out i know someone who can repair mine!!!!! cheers
Hi, if by any chance somebody could supply me with schematics for a c audio ra3001, would be greatly appreciated!! Just found out i know someone who can repair mine!!!!! cheers
The k1058 and j162 parts are japanese transisters. They leave the first two letters of the part number off the case just to confuse you !
They should be 2SK1058 and 2SJ162.
A good source of japanese parts in the uk is www.grandata.co.uk
I have also replied to your other post . Send me your email address and I will send you the schematics.
Strarstruck
They should be 2SK1058 and 2SJ162.
A good source of japanese parts in the uk is www.grandata.co.uk
I have also replied to your other post . Send me your email address and I will send you the schematics.
Strarstruck