Dead power supply was the easy part

[Guest]

The AC mains adaptor for our S4 failed. They then used a separate external 12V DC supply which seemed to be successful for a few hours until the unit began to complain that the adaptor was not connected. INFO shows the battery voltage dropping as time passes.

I now suspect that the supply they were using was not regulating the current and only the internal impedance of the batteries kept it from being a complete short. There was some noticable heat near the power plug and now the PCB is browned near the bridge diodes. They may be open.

What are the common components to suspect in a failure like this? Is seeking some matching SMT diodes a likely course or should it be discarded and replaced?

S4 Burnout

[Dataman (Neil Parker)]

Hi,

It is difficult to say in these circumstances without actually examining the board. I can only suggest that you return the unit to us for inspection/repair, there is a flat rate charge of £95 +VAT + Carriage. There will be no charge if the unit cannot be repaired. We will simply return it to you if you wish.

Hope this helps.

Neil