(If yours is not a Samsung, please reply back with your brand and model!)
Sadly, we hear of this over and over.
is due to a defective or loose magnetron causing electrical
interference and disruption in the control circuit board.
your magnetron was recently replaced, it may have loose mounting nuts
or bolts or maybe the wire mesh RF gasket was not installed or got
It may also need a new high-voltage diode and stirrer, and the cavity may be affected.
you or someone you know decide to look into it, we have critical
information on safety, disassembly and door switches at our site, and
our link is at our listing here on FixYa
it's within the magnetron portion of the warranty (usually 5-9 years)
but out of the original full warranty (usually 1 year), then your
manufacturer will cover the part cost, but not the cost to visit you or
the labor charge to do the work.
They may even send you a replacement magnetron.
You can order Samsung parts here
. You can find your nearest Samsung-authorized service center here
.We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.