Cycle Analyst V3, backlight but no text

[Sparfuchs]

Hello EV friends,

I build a bike with a unlocked Sabvoton SVMC 72150, a CA V3, a mxus 3k Motor and a 19s battery with a bluetooth ant bms.
I connected and programmed everything and it worked great when I tested all the functions (on the bike stand/ no load).
Then I organized and zip tied all the wires and when I finished I closed the ignition but neither the Sabvoton nor the CA worked anymore. The CA backlight of the Display was on but without any text and the Sabvoton led was flashing red and green and said "throttle release err" in the software (but normal values measured on throttle. 0,8V- ca. 4V)

I've no Idea what might have happened from everything works great to nothing works.

Just to mention it.. while I organized the wires I charged my programmable battery for the first time but it seemed to work like expected. And the Hall test always showed "in progress" but didn't do anything so I set the values manually. But I don't think that's related to the problem ?

++++++++++++++++++++++++++++++++++++++++++

I've already opened a thread for the Sabvoton problem, so I'd like to solve the CA problem in this thread.


I disconnected everything and minimized it to the Battery + and GND and tried again but it did't work (only backlight).

I thought that there might have come something loose in the Sabvoton AND as a coincidence also the CA, so I opened them both up and checked all the wires, solder spots. Everything seemed fine to me.



I've no idea what to try or do and need your help

Best regards
Sparfuchs
Top

 

[amberwolf]

The CA backlight of the Display was on but without any text

That happens:
when the battery voltage is reversed (which usually blows up the regulator so correcting the polarity won't make it work)
or
when the load on it's 10V output (like for torque sensors, etc) exceeds a certain amount (less power available the higher the battery voltage is) (which also usually blows up the regulator, so removing the load won't make it work)
or
when the load on the 5v (throttle, ebrake, etc) exceeds the available current (this doesn't usually blow up the regulator, unless it's kept too heavily loaded for too long).

Shorting any of the non-battery-voltage-level controller/shunt bundle of wires (shunt +/-, throttle, speed, ground) to battery voltage can also blow up the regulator, or the MCU itself, and give you a backlit but blank display.


There may be other miswires or shorts that can cause it too, but those are all ones I've seen myself or in other people's problem threads.

 

[Sparfuchs]

Thanks a lot for your helpful reply amberwolf,

so even if I haven't found any problem all the symptoms seem to indicate that it's however it happened damaged now ?

I'll see what grin says about the warranty.

Does anyone know how to repair that ? Could I somehow change the regulator ?

And as I haven't got any answers on the thread with the sabvoton problem... Do you maybe know what might be the problem there ?

 

[amberwolf]

Assuming it's the regulator it can be repaired as long as that is the only damage--if there was reversed voltage it might not be the only thing, but once it's fixed you can test everything else to see what is or isnt' working. There is some info on that part of the circuit in the CA repair thread I started some years back, I think at the top of the second page.

Note that the CA can work without the regulator if it's just the pass transistor that failed--but you have to use an external low-voltage source to power it; it can't directly run off the battery voltage anymore without it. There is info on how to do that in that thread, too.

There could be some other problem instead, of course, that I don't have experience with.