faulty security light

[someonelse]

My mum has a security spotlight (not this one but similar looking):

http://www.qvsdirect.com/170-LED-PIR-Floodlight-Black-pr-25557.html

It has two dials on the PIR: one to alter the time on period and one to alter the light sensitivity.

When I visited today (afternoon) I noticed it was on, and staying on.

Clearly
a) it should not have been on as there was no movement activating it
b) it should not have been on as it was daylight and
c) it should have switched off after a few minutes but didn't

I adjusted the dials (no response), switched it off, and then later on again (same result, stayed permenantly on).

Has the PIR and other functionality died?
Or is there some other possible reason/remedial action?

My instinct is a complete replacement is needed, but thought I'd ask here first.

Cheers!

 

[EFLImpudence]

I adjusted the dials (no response), switched it off, and then later on again (same result, stayed permenantly on).

If it did, indeed, stay permanently on then it would appear that the PIR is faulty.

However, when turned on (after a while off) normally the light will stay on for the set time (upto 20 minutes?) before reverting to automatic mode.