piezo worn out issue

[harp]

I wonder if it is real, or missleading some other problem? ?............... https://m.youtube.com/watch?v=ceb09rxPohA ?....... in video is presented claims that new piezo fix problem of poor production of moist, what is electronic science stand behind that conclusion? Can piezo be worn out and hot to tested it for that condition.............. in the past I see video where is piezo torturing through test vith high voltage, various frequency, and it is amazing what can survive and operate after damaged.

[harp]

https://m.youtube.com/watch?v=-G16BPb2PKw ?.................. Piezo Speaker vs 1000v

[CapLeaker]

nothing surprises me in that vid. He probably bought it on Wish.

[stj]

piezo elements can fail for several reasons.
drive them card enough and the ceramic wafer can crack,
if they get really old the silver layer can tarnish and flake off,
and if they get wd40 or some other things on them the silver layer can flake off.
NEVER solder to them without solder that is atleast 5% silver or it will desolve the plating btw.

[harp]

Yes, the video dont explain too much, but on many places people have same problem, and on some they claim that replacing piezo fix it... https://www.shroomery.org/forums/sho...umber/27864401 Short stoty... Before a few years ago I was received a ultrasonic difusor to repair, the fault is described like "first few seconds produce mist, than rapidly reduce, still working (boubling in bath) but nothing mist came out...".................. http://www.youtube.com/watch?v=jJS8D6AHpOs ...from that description, I only briefly check with water in bath if they initialy work (and it was), and promptly open device for measurement (so I do not check for fully initial claims in fault description)....... I see nice burned pcb behind mosfet, but mosfet is reading good with dmm and transistor tester. I managed to make a copper heatsink on it, and after assembled I tested over 8 hours in continuity, full power, where hour by hour got stable production of mist about 30g/h, stable temperature in bath and on mosfet heatsink (no any noticable heating)............... So, I think that simptoms is connected with previous overheating of mosfet, and belive that I fix device, certainly I have proof because filming video, where is mist produced flawlessly............... But, after transport back I got information that nothing changed, same fault description............ Because device is from my friend, he send me device again and tell let it keep it for myself. I now collecting information, because, after cleaning it well (with water, vineger, its clean like new) I can confirm the original fault description, and can not understand what happend to it that in some case work ok, and in some not... If the piezo is worn out, why initialy work well? I am sorry for the mess, from recently I cant quote properly... https://www.badcaps.net/forum/genera...28#post3474728