Problem with PIR-sensor

Hallo! Recently bought a PIR-sensor, DYP-ME003. I tried lots of scatches from network, read lots of articles - but PIR still doesn't work properly. I don't use any additional resisters etc, just do everything straightforward. Here is a description of what I get as a result: PIR sends a High sygnal whenever it wants to. Have got a feeling that movements, appearing/disappearing from a field doesn't influence the result. Sometimes PIR turns to low signal, but it also happens whenever it wants. There are two mods of work (jumper on PIR defines it). The description I gave above concerns a first mode, when H pin is covered with jumper.

The symptoms in another mode are even worse - PIR just sends low and high signals one after another with the same period. What's the matter and the reason of such a behaviour? Is my PIR broken?

btw, question about another sensor - a bare gas sensor, MQ-5. What's the best way to connect it to board? Distance between pins doesn't allow me to insert it to the breadboard, and I don't wanna solder it anywhere.

Did you test it:

Hm. I've just tested the same way as in given article. Without program, voltage only :) The same behaviour in both modes. BUT! I tested it by using Arduino's 5v and gnd pins again as currently I don't have such a battery-holder thing (and batteries, by the way) as on picture.

So, there are two variants, I suppose: either the PIR is broken or the voltage is instable (have just read some topics about Paralax instability cause of voltage problems. The symptoms were very much alike). In case if PIR is ok and problem is a power, is there some way to fix it (besides trying to use another power-source)?

The power from the Arduino should be fine. My guess would be that you got a bad PIR.

Thank you, you were right! I just bought another sensor and it works really the way it has to! Thank you!