Mackie swa1501 copper trace damaged

[daniels75]

Hi to all...
I'm Daniel from Italy... I have found this forum on the net and I hope anyone can help me...I started this new thread as advised in the official thread of mackie swa1501..
I have buy a module amplifier of an swa1501 used...I buy it becouse I'm projecting to make an active subwoofer using a eminence sub and this module amplifier...whn I buy it, the seller tell me that the module don't power on... I have controlled it and I have found a fuse blow...the fuse is a small fuse (when I replace it ind the motherboard is write "F1A" and near there are write "F2". in the fuse was write "T1L250W". i replace it wih another but when I power on the fuse blow another time...I have found a circuit board broken...(see this image: View image: 20042011143 and this: View image: 20042011144 )

do you think is possible repare it???
can you help me to find the problem and repair it???
thenk you very much..

[52 Bill]

It sounds like you have some major component problems with this amp. At least the output transistors are shorted.

What sort of test equipment do you have available? How handy are you at working on electronic devices?

[Phostenix]

Enzo posted a good summary of how to repair one of these here:
http://music-electronics-forum.com/t20370/

Take a look at his post & see if you are willing to do that.

[daniels75]

does anyone know the code and data of the fuse?
I would not like that was what was different and it burns

[plec.22]

I've got the diagram some where for this mackie I'll look it out and check the fuse ratings and post it here..

[plec.22]

Evening all...

so after repairing this sub amp all is ok now..so for those of you who are pulling there hair out trying to get there's to work.

Here is a break down of the repair work carried out on this mackie swa1501 sub amplifier.. to start, with all the fuses blown black?? so it was down to cold checking of the many parts with out schematic to hand. The was many many shorted parts to the main amplifier pcb plus burnt tracks and it was in a right mess.

main o/p devices short circuit followed by the following components==
Q7 is the bias tracking transistor(Darlington)t122.
Q17/ Q14/Q5/Q18/Q12/...damaged Q9/Q8 these are found to be leaky..
R64(56 ohm times 2 o/c even the 2.2 ohms feed resistors o/c. many many diodes had been s/c D29/27 3.3v zens s/c D26 o/c. even found D44 this is a small led o/p.

plus replace ic hcpl-3100 within the floating ht rail.

Now after powering it up only one led lit up d15 this is the -15 rail volts so no + rail?? this turned out that its track under the cap feeding it's +/- volts supply was o/c so linked wire from power cap to bridge rectifier then powered up using lamp limiter all came up nice so.

Sometimes it takes lots of time to get into things so don't give up!!

Happy trail's.

[Jazz P Bass]

By the way, the fuse, F2, is a 1 amp, slow blow (time delay).

[plec.22]

yep..someone stuck a 6.3amp in the 8amp place plus 2.5 in the 1amp place...not good..

all correct fuses are in..