The label on the transformer indicated that it was a 230V-12V step down. I chose the latter since the laminated core appeared to be of good quality. So, the transformer needed to be either replaced or re-wound.

When I finally removed the transformer, I found the primary winding burnt and damaged. Since the wires weren’t long enough, I had to remove the fuse holder PCB too and then desolder the primary connections of the transformer from the PCB. So, I proceeded to remove the transformer, which was held in place with two screws. It would be foolish to replace it with a new one without investigating why it blew.

Also hidden away from view was the AC Power Transformer, which was fitted inside the same wall as the sub-woofer. Once done, there was this small PCB with just a fuse fixed inside. I needed to remove the sub-woofer to see what was connected to the bunch of wires. But, the AC Power cord along with a bunch of wires were routed into the speaker enclosure with some kind of adhesive glue to seal the gaps around the wires. The PCB appeared to be quite normal and healthy. Once again, I repeated the ‘Pre-Surgery’ checks – visual, odour, etc. Two 2-pin connectors on the PCB itelf provided connections, one to an AC Power transformer, and the other to the sub-woofer. On removing the screws, I found the sub-woofer speaker mounted facing down on the speaker cabinet and the amplifier PCB mounted inside the bottom cover that I detached. I found the only visible screws on the bottom cover with the speaker grill. I figured out that the power supply must be the first suspect unless the amplifier IC had gone up in smoke too. Next, a passive electrical check to see if there are any abnormally low resistances that could create an unsafe condition when powered up.

Details of this process could wait for a separate post, but I will briefly mention these steps.įirst, a visual examination to capture what could look like broken or damaged or burnt or incorrectly handled gadget. I refer to this as “Pre-surgery examination”. So, I carried out the customary preliminary checks. She said that it was working beautifully till there was an AC Mains surge that knocked out not only this amp but also a few other appliances around the house. This consists of three units – The main unit with the sub-woofer, amplifier and power supply, and two separate satellite speaker units. This is about an Altec Lansing audio amplifier ATP3, that my daughter brought to me for repair.

Speaker better than altec lansing atp3