SakisMx said:
BobBob said:
I would compare the blown channel with the good ones. It is likely that voltages on the control circuits will be similar and you have 6 sets of the same circuit so hopefully can see if something is different.
Can you guide me as to what I have to check? I only have a multimeter but I can give the board to a shop to get checked.
Set the meter to volts
measure the volts on the FET next door, then the one next to that and work out the pattern
see if the blown one is the same or different.
The way the controller works is there is a microcontroller that is the brain but has weak signals - it switches some little tiny switches (small FETS) which are three pin black rectangles connected to the big FET gate.
To figure out whether it is working you need to know if the brain is working, if it is signalling the little FETs and if they are signaling the big FETS. You can start with the big ones and work back. If you find that the micro (lots of pins big chip) is signalling but the little FET is not then you may need to very carefully replace that FET - I've soldered lots but use lead solder and you will need a steady hand and either good eyesight, glasses or a magnifier.
Best of luck
SakisMx said:
JackFlorey said:
One thing you might try is to cut all the MOSFETs off (assuming they are leaded) and try running it again; also spin the wheel by hand (if it's sensored.) You won't get any output. But if you have access to a scope, take a look at the gate drive pin for each of the MOSFET legs. If at least the bottom side is wiggling up and down* then the FET drivers are probably OK.
(* - to check this use a scope, or if that's not available, use a regular voltmeter. It should be some intermediate voltage, like 6V.)
So If understood correctly, If I remove all the mosfets and run it like that I should get 6V on each mosfets gate pin,right? Also when I spin the wheel I should look again for 6V on the gate pins, right? My motor has hall sensors and controller works both sensored and sensorless.My multimeter however is for 10A maximum and if I pass more current through I will fry it,so can I check gate voltage or I will fry it?
First, read up on how to use a multimeter and don't use the amps setting until you understand why I am saying this or you will indeed blow the (hopefully fuse in the) meter.
Use the volts setting to check for voltages, if you ever need to check amps then suggest you get a clamp meter
All the mosfets? I assume you mean the blown ones?
Easiest thing may simply be to replace the blown mosfets and see if it works if it's a cheap controller
or check if the voltages are the same on the replaced ones as on the others, if not replace the drivers, if so maybe it's fixed.
Another alternative is, as you say, take it to a shop - pretty simple circuit for them to figure out - might be best to take the bike so they can check with the motor and battery
Get a quote for the work first etc, insist on good quality mosfets to replace the blown ones.
Note that this is not a detailed troubleshooting guide and assumes you are not too bothered about learning the detail of how it all works. If you are, dive into some online tutorials first about how to use a scope, how to diagnose electrical faults etc. Lots to learn.