losing signal with psp290

hi,
i bought a psp290 from ebay and i remember that i was actually happy when trying it out.
Now it seems a bit different, because my psp290 seems to lose its signal. even AFTER having fixed about 3 satellites gps status switches back to off, then activating again.
This once happened about half an hour (could also have been the initlocation i changed).
I also noticed that it turnes itself off when screwing it in with its screw too tight or when pressing it down a bit harder onto the psp.

Do you think its broken, tuning out me to be the lucker again ^^?
or is it normal and its just some sensitive tool?

This is something that I noticed when making my own extension cable for the GPS unit. if i pushed the wires I was using into the psp too firmly then it would cut out and restart and sometimes it would simply cut power to the GPS device like you describe in your post. but a device that's firmly screwed into the top of the psp shouldn't randomly loose it's signal assuming it had a fairly strong signal (usually 5-6 satellites for me)