All four (IS215T)of the pir's not working thus setting the zones as triggered, i tested the board and you get 13v across the two terminals, if you loop out each zone the alarm works fine.
But obviously has a fault on it, to wipe out 4 pirs all at once.

 

There is no explanation to why they have been set off, as the room was empty, then another pir would do the same, but on a different time of day etc this is without the alarm being set, no tamper is being recorded on the LCD key pad.
Now all four zones with these pir's fitted have the alarm triggered on walk test and the alarm wont set, there is 13v power at the panel and the pir end all wires have been continuity checked and are ok.
No red movement led is lighting on any of the four pir's, the fuse has continuity also.
If i disconnect any of the pir and loop them out with a staple at the panel then that zone goes to unset/not triggered.
i have got a door contact on another zone that is working fine, along with the internal extension speaker and PA button.
Is it possible something is faulty on the panel and thus caused the failure of the four pir's.

Could be but id be surprised.
First I check day mode current
Dc supply voltage at the detectors
And ac ripple on the cabling
What do you have connected to the panel?
If you could post the readings above please

the voltage at the board is 13.3v dcwith no voltage drop to the PIR's at 13.3v dcas very short runs of cable, the Ac is 235v ac with not much variation at time of test.
All i have connected to the board are the 4 PIR's supplied in the kit model IS215T and the door contact.
A Honeywell PA button and a Sonit1 Speaker .
Everything else is working apart from the PIR's, but regarding the system false triggers, which show no fault recordings, i have no way of telling if this is fixed or still at fault, due to not being able to set the system, apart from the door switch.

So are the pirs still all in alarm?

All the PIR's are in alarm activated position, as if someone had walked into the room and activated them.
if you disconnected from the zone they are connected to on the PCB, the alarm will set if you place a staple across to complete the circuit on the PCB zone. so the Zones on the PCB are working correctly.
If i connected a door contact to each zone the PIR's have been connected to and activate the make and break of it each zone works perfectly.
No LED lights are showing on either of the four PIR's, the only common factor these PIR's have is they are all connected to the same power supply on the PCB, that has come to my conclusion the PCB is at fault hence the fault on all four PIR's

I cant prove the power at the PCB for PIR's etc is not also the false trigger the alarm is getting in the first place,as it may not happen at time of visit.

Have you removed the End of Line Links?

It does sound like the pirs have no power. On a pir if there is no power they will be in alarm. Do the walk test less illuminate on the pirs