Re: Altec Lansing ATP3 Speaker system transformer failed.

On 4/29/2024 1:28 AM, Liz Tuddenham wrote:

Bob F <bobnospam@gmail.com> wrote:
 [...]

No output. Ohmmeter resistance shows infinite on primary and secondary.
2 leads on primary, 2 on secondary, going to 4 diodes on the circuit board.

 Does it look badly burnt or is there no physical sign of stress?

No sign of either. I just pulled out the circuit board, and no visual sign of damage. The diodes and cap on the power input to the board test OK.

 It would be very unlikely that both windings would go O/C simultaneously
unless it had failed catastrophically and that would be rather obvious
from the outside.

Kind of weird. It worked one day, but not at all the following morning.

 Simple question:  Did you measure the resistance between the two ends of
the same winding or are the terminals laid out in a confusing way, so
you measured resistance between two different windings?

I measured across the wires going toward the power cord for the primary, and the wires going to the circuit board for the secondary. 2 pairs of wires completely different wires, one pair from each side.
I moved a system that used to be used in my exercise room up, and it fit in my space, so no crisis. Maybe I will try unwinding the transformer coil some time I'm feeling bored.