Cequra Super plus strobe problem

[timop001]

Odd problem.
Changed 10yr old Cequra1 box about 18 months ago for a Cequra Super plus. All seemed to work but on routine check after a few months I found the strobe was only working intermittently - flash a few times then give up or not at all. I thought it was a board fault and swapped to a new identical unit I keep as a spare. This appeared to work initially but soon developed same problem. Tried a third - same story. Never a problem with the siren circuit. Checked wiring to box is good.
Bench tested with 12vdc and the strobes worked but did appear a worryingly flakey at times. Cequra customer service say that there are no known strobe problems with this unit.
Checked Comfort outputs (PC01-070A ULT 7.x)
RTN -- tamper
Hold off+ -- SRN+
Hold off neg -- COM
Siren -- SRN-
Strobe -- STB-

With 1k resistors fitted and connected to box;
SRN+>STR- 1.2v off, 13.1v on
STR->COM 12.5v off, 0.6v on
SRN+>COM 13.7v
On open circuit with resistors, the values are about the same.

This looks correct to me. Comfort is pulling the STB- output to <3v when on.
Can\'t fathom out what is the problem here. 3 bell boxes with dodgy boards ? Excessive current requirement ? Anyone else come across this? Should I ditch the boxes and try a newer LED unit - I understand these are 10yr old design? Thoughts appreciated.

[slychiu]

Measure the strobe voltage STR- after the strobe light goes offIf the voltage is still close to 0, then there is voltage applied to the strobe but the dtrobe is not working so it should be a strobe problem

[timop001]

Not quite sure I understand Chiu.

Do you mean the SRN+ to STR- voltage ?And \"goes off\" is strobe active or inactive?

When the strobe is active SRN+>STR- is 13.1v meaning STR- has been pulled low as expected.Whereas inactive it is 1.2v.
This suggests a strobe problem.

[slychiu]

when the strobe is turned on/active SRN+/STR- is 12V and when off/inactive it should be close to 0
That is the correct voltage for a working strobe
You say the strobe turns off when it should not. So does that mean that the voltage is still applied? That would mean the strobe is faultry
The strobe may also become inactive due to a timermij which case Comfirt will rturn off the voltage.
So I am trying to establish which case is is

[timop001]

Ah..

Comfort appears to always apply the correct voltage.

When strobe stops unexpectedly, SRN+>STR- is still 12v i.e. the trigger voltage is still applied. It is not a Comfort timer problem. I am not aware of a timer on the Cequra which would only allow a few flashes before stopping.

I think we are agreed that Comfort is working correctly and for whatever reason 3 Cequra units have failed.

[timop001]

Just to close this thread - I have fitted a new CQR Senza with LED strobe which appears to be working as expected.


Learning point - 3 bell unit failures, including new units, is exceptional but obviously does occur. Must be a design fault which has taken me several months to bottom out. As Sherlock said, \"Once you have eliminated the impossible...\". Thanks for the input Chiu.

[timop001]

I think I have solved this conundrum.

Mea culpa

During my refit I must have set the SystemSet alarm response to have the strobe on - this meant the strobe was on ALL the time the system was armed. The xenons only have a life of 1million flashes and I didn\'t notice the strobe flashing when armed. The xenons expired from running all the time and were therefore flaky.

Only just noticed this on the new LED strobe and spotted the alarm setting mistake.

So 3 boxes DO NOT failure but this installer frequently does!hock: