Shimano STEPS malfunction

[colinb4987]

Hoping someone can help me out here.

I have a Shimano driven cargo bike with DU-EP800, SC-EM800, and battery BT-EN606. I've had it for a few years now, it's never been reliably trouble free.but I've always managed to fix any electrical gremlins.

Recently though, it's got me completely stumped. Here's the situation:
* Battery is fully charged
* Powering on from battery, computer beeps, displays boot screen for approx 7s, before going blank
* At this point both computer and battery are blank with no power delivered to pedals
* SM-PCE02 can connect, and always detects drive unit and computer. Firmware up to date,.4.1.11 and 4.3.0 respectively
* PCE02 sometimes detects an Unknown battery, reporting Firmware versions unknown, 2nd Gen Battery, SUPPORTED BY SHIMANO
* PCE02 sometimes doesn't detect even this much
* No errors reported in Drive Unit error log
* Battery error log is inaccessible

Anyone have any clue what on earth might be going on?!

 

[wenna]

I would try to reinstall battery firmware as well as check all the cables and connections.

 

[colinb4987]

I would try to reinstall battery firmware as well as check all the cables and connections.

Cables/connections all checked, nothing obviously loose or damaged.

How do I reinstall battery firmware?

 

[RustyIron]

I suspect the battery in your Power On/Off switch.

 

[colinb4987]

I suspect the battery in your Power On/Off switch.

The only on/off switch is on the battery itself, no remote on/off. No obvious way to replace a (I assume coin) cell for the battery mounted switch, unless I'm going blind