I was hoping it would be a 4-wire one because 5-wire ones can be analogue or digital.
OK, we're going to have to find out. There are two ways. either way you have to follow the green and yellow wires to where they're soldered either in the controller or in the control panel.
As the the panel is unserviceable, I'd go there . You need to open it up. if you're lucky, it'll have screws otherwise it'll be glued and need to be cut open. If screwed, they normally have some sealant between the two halfs, so you need a bit of leverage to open it agter the screws are out. Once open, you can see where the wires are soldered, and you might be able to see an obvious fault, like a wire off or water damage. What you need is the markings on the pcb where the wires are soldered. Tx and Rx means digital. Anything else means analogue.
As there is no light switch, it's most likely digital, but we need to be sure before telling you which one to spend your money on.
That looks like a KT label grinning at us from under the red Batribike one, and the engraved serial number also looks typical KT. I don't think I've seen a KT on a mainstream OEM bike before. If it's not too much trouble, see if you can steam off the red label to see what's on the one underneath.
I'm pretty sure that it's a Batribike-branded KT 880 LED display, but you still should check. if it is, there are lots of options for replacement.
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