Faulty 3D Touch sensor

[buliwyf]

Hello,

i ordered the sensor via Aliexpress and it arrived two days ago.
But i seems to be defective. After powering on the printer it does the selftest, but only two times.
After that it sometimes shows an alarm and sometimes not.
When no alarm goes off the sensors seems to work.
This is also the case if it goes to alarm and i reset the sensor with M280 P0 S160.
I then can start e.g. an autobedlevel with G29 but it might happen that during the leveling the sensor does not put out the pin
an so the nozzle hits the bed.
If i test the sensor with M280 P0 S120 the sensor works forever.
I don't think this behaviour is normal. Especially that during the selftest the pin goes out only 2 times.
So might the sensor be defective?

Thanks for your help.
buliwyf

[Saikerone]

I also received a faulty sensor. It retracts twice. And then no alarm no red light nothing. When I give gcode commands nothing happens. When I give a g28 command the nozzle slams into bed. Can you send me a replacement or my money back please? Ordered here at geeetech.com

[bang]

Why do you guys think the self-test is three times not twice?As far as i know,it is twice on this sensor and differs from other sensors.

Then concerning eliminating the alarm,refer to this post:
viewtopic.php?f=27&t=18371

[Saikerone]

I thought so because it's written in the geeetech manual. But anyway last night I took out All the connectors and soldered everything. After that it worked! Guess I got a bad connection somewhere. Will try to level bed today.

[bang]

Great.

[buliwyf]

Why do you guys think the self-test is three times not twice?

Because it was mentioned on the seller page at Aliexpress. Which was altered by now to two times.
i can still look at the original text which clearly says three times.

And the linked documents in
viewtopic.php?f=27&t=18263&hilit=3d+touch+manual
both say:

Self-test: The push pin is operated three times to test when the power is on

I'm going to test the sensor today again just to check weather i get faulty reading.