In article ,
phantomzone writes:
I've recently been doing some redecoration which necessitated the
removal of a PIR.
When I put it back I seemed to have damaged it somehow.
The alarm panel is now showing a constant tamper fault light which I
can't deactivate.

Usually just removing and replacing the cover does the trick but this
time it's with no effect.
I don't know how the tamper sensor works so can't work out what else
to try with the PIR itself.

In most (particularly cheap, home) PIRs, it's nothing more than
a mechanical contact, e.g. a microswitch, piece of bent metal,
or a spring pressing on a PCB mounted minature push button
mechanisn.

In some more expensive PIRs, it's a signal generated by the
microcontroller. It will operate if the unit loses power
(probably not in the case of a wireless sensor) or if the
microcontroller detects a fault in the unit.

The system is, quite an old, Scantronic 4700 system with wireless
PIRs.

I don't have the engineer code for this box only the general activate/
deactivate code.

Some panels will require (or can be programmed to require) the
engineer code after a tamper fault even if the fault is cleared.
Sounds like you know from past experience that isn't the case
with yours though?

Can I replace the PIR using something generic? I'd rather not have to
replace the entire system as this one does the job very well normally.

Wired ones, yes. Wireless tends to require the exact same part,
which are usually no longer available by the time one breaks :-(.
However, I don't know about your Scantronic.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]