S4 in loop turning on and off

[mgarnett02]

Hi,

I have an S4 that is continuously turning on and off in an endless cycle and the beeper beeps each time.

So, when I turn the S4 on, I see the start up screen, then the S4 resets after a fraction of a second back to the startup screen, the beeper beeps and the cycle continues. I have tried pressing the reset button down for 30 seconds both with and without the charger plugged in, before and after turning it on, but it doesn’t change the behaviour. If I am quick enough at pressing the INFO button I briefly see that the charger is is OFF, but the voltage still seems to be around 8.8 volts but it is hard to read it flashes so fast.

The only way I have found to stop the cycle is by pressing the REC key to change to communication protocol, but is soon as I escape from that option or press INFO, the cycle resumes so there’s no way for me to change the battery charger from OFF to ON. I have followed the procedures for recharging completely dead batteries, but without success. There doesn’t seem to be a way to interrupt this cycle other than this.

When the charger is not plugged in, the reset cycle is a fraction of a second slower than when it is plugged in (it resets on ons off faster with the charger plugged in so it seems to “know” it is there).

Could this be NiCad battery related? The internal lithium battery is still showing at around 3.7 volts.

If I could describe this in one sentence, it looks like something is causing the device to continuously reset.

Any ideas? It’s a banged up ,unit but I would really like to keep it going.

Cheers

Mark

[Dataman (Neil Parker)]

Hello Mark,

Thank you for reaching out to us regarding the issues you're experiencing with your S4 device. I apologize for the inconvenience caused by the continuous resetting and beeping cycle. After thoroughly checking our repair logs, I couldn't find any similar reports or documented solutions for this particular problem.

Given the symptoms you described, it seems like there may be a hardware or internal component issue causing the continuous reset. However, without further diagnostics and examination of the device, it's challenging to pinpoint the exact cause.

It might be worth running the unit from a DC bench supply in place of the nicad. Set the supply to about 9.2V @ ~1A and see if the unit powers on and stays on.

Perhaps another user might have a suggestion on how to troubleshoot this.

If you have any questions please contact me.

Best regards,

Neil Parker
Dataman Programmers

[mgarnett02]

Thanks for the reply, much appreciated.

This is a very beat up old unit, having suffered massive corrosive damage on the PCB, I’ve managed to keep repairing it and keep it running, but think the underlying corrosion is still eating away and is causing damage slowly over time.

I think the only way to really fix this now is to replace the PCB, so if you know of a source for a bare or populated PCB for the S4, then I’d love to track one down and fix this device once and for all.

Thanks again.

Cheers

Mark

[Dataman (Neil Parker)]

I would suggest setting up a saved search on eBay as we see the S4 come up on there from time to time in various states, sometimes fully working.

If you have any questions please contact me.

Best regards,

Neil Parker
Dataman Programmers