As a newbie I haven't seen many ESC variants. The one I have exhibits 4 MOSFETs in line. They come in many packages but TO-220 is cheap and common. They are usually connected in a H bridge ( google that). You can test or just replace all4. Get a soldering iron and a solder removal pump. You also need a DVM if you are going to test. Then you can remove all 4 noting the numbers on the package as you go and test individually. When removing, if you are just going to replace, cut the pins, remove the MOSFET body and then remove individual pins. Google the numbers to find which is N and which is P. You can then get a datasheet. Ignore everything except VDS and Id- that's Volts and Current which is power.
Any decent electronics supplier AKA CPC.co.uk will have a selection of spares. You need 2 P types and 2 N types. Get the lowest possible VDS rating above 20Volts and an Id of at least 50Amps. Similar to the values you had originally. Hope for £1 or less each.
Solder them in, doing the OUTER 2 pins first. Do any adjustments then solder the middle pin.
Good luck....

Hi,
Belay the last. I have been on line and have identified what a MOS-FET looks like. If you think that is likely to be the problem I may have a go at removing and ordering a new one to solder in.

Thanks for the info
Kevin

Hi
I have in the past built an electronize controller bought as a self assembly kit. Could you describe what a mossfet looks like. I might be able to effect a repair. Would you be able to advise on how to test for a blown mossfet.
Regards
Kevin

As a newbie but good at electronics I am making my own speed controller for a brushed motor. I was a little surprised to see that heatsinks are often not used.
I'd guess that most faults will be due to blown up MosFets and these can be replaced as a set for a few pounds. On my device I am adding a current limit/ cut out so a stalled motor or stuck propeller does not cause blowups.

Thanks Ian.
Yes I agree a quality product andbritish made.

Regards
Kevin

Hi,

There was a thread on Mayhem last year about this. I have copied a bit from it below.

The situation with Electronize is this :-) they are doing very small numbers of speed controllers on request - there is no website now though - but, there is a telephone number available - but - this number is only available during office hours throughout the week = i.e. 9 a.m. to 4 p.m. (UK time).
Tel:
0121 308 7411

I don't know what the situation is now. It is a shame as they are brilliant speed controllers and I snapped up a couple on ebay a while ago- always worth looking out for, absolutely bomb, and in my case, idiot proof!😊

Good luck in your search.

Ian