There have been several reports of Pieps DSP avalanche transceivers accidentally turning off due to the design of the Off/Send/Search switch's "release tab." This tab is supposed to prevent the switch from inadvertently changing.
Pieps transceivers with press-to-release tabs include:
Of the above transceivers, only the Pieps Sport is still being sold.
There are two possible problems with the release tabs on these older transceivers. One is that the plastic tab can crack or fail to lock. This should be identified by looking for cracks during periodic physical inspections and by checking to make sure the switch can't be moved without pressing the release tab.
This Instagram post contains a video explaining how to inspect the switch on DSP transceivers. The video points out that forcing the switch to move, without pressing the release button, can damage the switch.
The second possible problem occurs when the tab is inadvertently pressed (which releases the switch) and then a force causes the switch to slide to the Off position. This can occur if the transceiver is put in its harness backwards (i.e., with the screen facing outward), something presses on the harness's buckle which in turn presses on the release tab. You can see this in this YouTube video.
This problem is more likely if the transceiver is in the harness with the screen facing outward, because the buckle can then press on the release switch. However, there are online videos showing that the release button can be pressed when the transceiver is correctly inserted in the harness. This has undeniably happened to people, but it does seem like an outlier situation (pressure on the beacon sufficient to press the small release switch and then an inline force to move the Off/Send/Search switch). On the half-dozen or so DSPs I own, the sliding switches are extremely stiff and difficult to slide.
Pieps is offering to upgrade DSP Pro and Sport transceivers. Depending on the age of your Sport transceiver, it may be covered by warranty.
Bottom Line: (1) Physically inspect your avalanche transceiver periodically regardless of the model. (2) Insert your avalanche transceiver, regardless of the model, with the screen facing toward your body. (3) If your transceiver has a press-to-release switch tab, consider whether the release tab could get inadvertently pressed.
If you do encounter a problem with your transceiver's switch, please send me a note.