SX 1250 Start Up Issue

[C J Brown]

About a week ago when starting up my SX 1250 I heard a loud "pop" noise from behind the unit.

Similar to what is heard in a home electric system due to a fault of some kind creating an arc.

This happened right at start right after the soft start relay but before the speaker protection relay clicked.

The system came on and played OK.

Since then when starting up I hear the second relay popping sound in my right speaker only. Not in the left channel.

This occurs when using speaker A, B or C. Or when using headphones. Placing the balance all the way to the left produces silence - no pops heard.

Today I first noticed that a pop created by static electricity when first touching the SX 1250 was heard on the right speaker before turning the unit on.

Does anyone have any cause theories?

 

[mrk229]

A couple of thoughts.
Initial pop noise from a failing or failure in the soft start.
Initial pop noise a capacitor exploded. You can usually smell them.

Second popping sound. Check for DC voltage on the right channel speaker output. If it is more than 50mV time to pop the top and dig deeper.

 

[zebulon1]

I wonder too.
The first thing I would check is the protection board for that possible damaged cap. The pop from the right channel might be normal but it’s not muted as it should be on start up. The protection relay might be engaging too soon?
Regardless. Any Pioneer piece of equipment that hasn’t been checked out by now probably needs a good going through.
Check the amp settings to make sure they are correct and stable. Then go right to the protection board.