Mackie SWA1501

[av.sorong]

yupp sir...

Dear sir,

Thats right as your explaining. I worry if my friend still have stock... Sure if i have a chance to take a shoot, i will upload to this thread...

[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 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...the only thing I have see is the "R1" (where is write "ROYAL 252 5W 4K7J") wich is hot...
can you help me to find the problem and repair it???
thenk you very much..

[J M Fahey]

As you might imagine after finding 121 earlier posts about this module, you are getting yourself into boiling water.
Why did you buy a non-working module?

[daniels75]

As you might imagine after finding 121 earlier posts about this module, you are getting yourself into boiling water.
Why did you buy a non-working module?

Unfortunately I found this forum after buying the amplifier module ...
I bought it because I paid little and I thought the problem was solved...

[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 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...the only thing I have see is the "R1" (where is write "ROYAL 252 5W 4K7J") wich is hot...
can you help me to find the problem and repair it???
thenk you very much..

I think I have found what's the problem...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???

[52 Bill]

The copper trace has been damaged because the transistor has drawn too much current.

Please start a new thread and there will be a lot of people here that will help you.

[daniels75]

The copper trace has been damaged because the transistor has drawn too much current.

Please start a new thread and there will be a lot of people here that will help you.

ok I open a new tread..thank you...

[jonberrier]

Just opened one of these up and on the 15v rail the filters are 10000uf 50v instead of 4700uf 50v as the schematic states. Trace from - on rectifier to the cap has burnt. I'm going back to the 4700uf caps. Anyone seen this before?

[J M Fahey]

Well, having 10000 uF caps instead of 5000uF ones most certainly is not your problem
Something else shorted and burnt that track.

[jonberrier]

You're right. One of the OP transistors was completely shorted as well as the fet on the high voltage rail. Also found R1 with a cold solder joint.

[Master Mechanic]

Got a question for the experts,
I have a sense of humour and plenty of time on my hands so have taken on the task of repairing the amplifier on my mackie SWA1501.It seems to have suffered from most of the problems previously mentioned with blown components (there are transistors with no legs on).I've removed all the soot and dust and have started fault finding by checking all the resistors on the amplifier and this is where I run into my first problem.
My question is can anyone confirm the values of resistors R14 & R22?The schematic says they should be 4.7k but both resistors fitted to my board are 5.6k,which value is correct?.I wondered if this has caused my amp to eventually fail.

[Jazz P Bass]

I would kindly advise that you start a new thread.
It is a PITA to navigate 130+ posts.

[MarkusBass]

I'm looking for a schematic of the preamp used in SWA1501. I fixed the power amp thanks to this thread (thanks to Enzo and others ) and now I'm looking at the preamp. Most probably fired opamps but I'd like to see the schematic.

Mark

[Jazz P Bass]

This is what I have.
SWA1801 preamp
It should be the same as the 1501?

[MarkusBass]

It looks like the preamp is the same but the problem is rather with the speaker (the amp owner brought me the cabinet). It's Mackie LC15/3007-8 and I think that it should be 8 Ohms speaker but measured with a multimeter it's less than 1 Ohm. Looks like shorted speaker. Should it be really 8 Ohms? I'm asking about it because in some posts in the Internet it is mentioned that the speaker is 16 Ohms. And I think that on the schematic it is listed as 12 Ohms. Which one is correct? I have to ask someone to recone the speaker but I need precise info on the speaker impedance.

Mark