You can check a FET with a DMM with diode test. First short the 3 pins with your finger. Then apply the negative probe to the source pin, it will be the the right pin on this fet, apply the positive probe to the left pin (Gate). This should power up the fet. Then move the positive probe to the middle pin (drain) you should get a reading or beep or whatever your dmm does. But if you short the pins again you should not get a reading between the drain and the source. On mine I get no reading even after charging it up.

Also to not, I can only find the one fet, which confuses me. I figured this would be a triple bridge with a fet controlling each phase. But it looks to use low voltage dual supply fast switches to control the phases. I am just starting my journey into electronics, so I am not quite sure how that works. But I do plan on ordering a fet for mine. But regardless it looks like someone at one point replaced one of those switches on mine as well sense the board trace is missing and instead has a piece of wire soldered into the input pin from the resistor.

In case someone was wondering, here is the number for the fet. IPD135N03LG

Edit: Those switches are fets as well.

According to a data sheet I found for si4564dy, which match the 4564 number on the part, they look to be 40v 10a N and P channel mosfets. I wonder if we can replace these with 30v 30a fets and up the current level they are capable of...
Anyway, according to the data sheet you should have s1 g1 o nthe top right and the drains on the bottom. If you are looking at the board with the inputs at the bottom. I tested resistance between the 4 bottom pins and they are all connected together so it makes sense for those to be the drains. Top right pin has a trace coming from the the resistors so those make sense to be the source.

All 3 of the fets on my board give different readings. If you probe the S1 with the negative probe and any of the drains with the positive I get a high reading on the two outer fets. I get no reading on the middle fet. But on the right fet if I probe the S2 I get continuity.

Just as a follow up. I received the new fets and switched them all out. Still has the same error...

On a positive note, I made a load tester that can be used with the Motolyser 2. It is the same old idea that has been used before. Test motor connected to a slave motor with resistors off the phases.

Here is a pic of a 13.5 with a USGT motor as the slave motor. I have 2ohm 100watt resistors off the slave motor. According to Motolyser, the unit can handle up to 20 amps. This setup is pulling roughly 12amps. For higher turn motors I have 1ohm resistors.

I am working on a sensor kit that would allow this to be run from an ESC and give output.

Did you make that slave motor stand?

Wrong thread

.

Yes I did.

Resurrecting the thread, has anyone managed to fix the overcurrent / over-temp problem?
My friend gave me a unit, and it's exhibiting the exact same symptoms.
It's able to spin the motor fine for the sensor test, but the full current test faults out after a second.

On the latest firmware, it wouldn't finish ever.
I downgraded to 2.1.1-gc1dd, which lets it finish once or twice before faulting, depending on the motor.

Is it a hardware problem in the end, or just terrible software progressions?

Small update, I went all the way back to version # 144, and it's at least consistent now.
2 runs and it over-heats, but then give it a few minutes and it works again.

Good enough I guess, is this how the units always were even when new?

Can you tell me where I can download the firmware files?

Can anyone share the old FW version? I too get the overcurrent warning if I go above 42deg on a 17.5 motor. Thanks for any help

I have version 148, but I will say the same thing Motolyser told me. Update at your own risk.

booted up 148 , back in business. I dont do a load of tuning so should be fine.