Simplex 4903-9361 Strobe issues

I also received a Simplex 4903-9361 Speaker/Strobe and need it to be set to free run until I get a smart sync module, since the 4005 cannot output a smart sync signal. I have confirmed it can be set to Free Run or Smart Sync, however when I flip the switch below the strobe to free run, it still acts in smart sync mode (NAC turns off and strobe flashes once). I also have a 4903-9427 and had a similar issue but was resolved by really pushing the switch the highest it can go without breaking and works fine. That didn’t work with the Speaker/Strobe. This device was bought used and is dusty so it had to of been working during service but it was in smart sync mode.

The drawing below is the switch setting in the installation instructions. It is possible the little switch is not making connection internally. The free run position is ON and it was in sync mode so the switch was OFF all these years. It is also possible the circuit that reads the switch is not working correctly. Double check the switch position and exercise it a few times. If it still will not go to free run I probably can come up with a way for the panel to flash it.



Thanks for the info. I’m just gonna leave it alone til I get the smart sync module. On another note, not related to this topic, how would I go about changing the default message on the 4003? Could it be done myself or do I need to call Simplex and have them do it?

The Simplex designed 4003 uses a custom chipset made for that voice controller board. It is labeled CSET600. That chip only has two messages in it. The evac message and the all clear message. To get a different message would require a sales order for a different custom chipset which would cost $$$.



You could flash the strobe every 3 seconds by changing the strobe NAC to SVISUAL or RVISUAL point type. Then in the SYSTEM OPTIONS programming menu setting Visual Evac to SMARCH. That gives a 3 second cycle with a 50% duty cycle which is 1.5 sec on and 1.5 sec off. The strobe cannot keep up with faster codes like temporal or march time because the duty cycle is too short for the circuit to completely charge up.

Looks like the default message is staying for now. I’ll see what I can do with the strobe circuit, but most likely I’ll just get a smart sync module next week. Thanks for all your help though!