Mackie Powered speaker problem

[argonrepublic]

I have a problem with Mackie SRM 350V2 powered speaker
We used it last week in Christmas parade. It stopped played and power LED flashes now.
I left in in my garage for a few days. I brought it in and while cold it turned on.
I tried a couple of other times and it just flashes.

I managed to get it to play yesterday. Here is what I have found:

1)At low level, it will play for 30 seconds max. If I turn it up at all, it shuts down immediately.

2)With from power indicator disconnected, amp doesn't power up at all.

3)With no input and gain all the way down, I attempted to check +/-15VDC. When I put black probe on ground, pwer light began to flash. When I put second probe on the clearly marked +15VDC terminal light came on and stayed on. that seemed odd because black probe only was connected. I tried a small screwdriver on the same terminal and got same results. I also toughed screwdriver on -15VDC terminal and light began blinking.

 

[pacificblue]

Check the fuses.

Ask Mackie for a service manual. They usually give you one, if you state the serial no. of the product.

 

[!]

I suspect a stress fracture of either the PCB, a solder joint, or a component body. Temperature change or pressure points may temporarily complete (or break) the circuit. When/while it is not coming on, probe around gently to see where the circuit is broken.

 

[argonrepublic]

Thanks very much! Silly me! I recently work on a synthesizer that would play a note just by touching a terminal on the key sensing circuit until I replaced a resistor network. You were right. I insulated my skin and touched around the board and was able to locate a dry joint on leg of a transformer.
Thanks