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Well, oddly I now have 2 Novak esc's from the same vintage with almost the same problem.

One of them, the 410 m1, I have had this issue since about 92 and the m5 I received from ebay in this condition.

They both have had one component fall off the pcb, the m1 component is lost to the sands of time so I don't even know what it is, but the m5 component was actually inside the ESC. The problem with that is it appears to be polarized with the white band and I do not know which direction it should go on the board, should the band go towards the fets or away from them?

On the m1, if someone has one laying around that they can see what goes in that spot and what orientation I would be thankful.

I am not sure sending them into Novak at this point would be at all useful

Red arrows point to the missing surface mount component and in the m5 picture the red circle in the lower left corner circles the component that fell off.

Thanks.

I've got a 410-M5 Sport if that's close enough.
Might take a day or two before I have a few minutes to open it up...
If no one else jumps in before then, I'll see what I can do

I was hoping the m5 would be close to the m1 when I bought it.. but it was completely different, I would assume if your sport is not the solder pop version it will likely be completely different as well.

I don't have it handy to check...it's buried in my workshop. We'll see - hopefully it can tell you something.

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Agreed with tamiyadan. I can see pH and then 22 on the diode on my unit, but it might have another digit facing the bottom between that. your part should have a part number on it. Should be able to get another for your other unit. If you can read the whole number, put it in the thread and we can find a suitable replacement.

ph- and 22 is all the writing there is and there is a space separating them on both ends so I could not say if the ph- or the 22 is first.. it just goes round and round and...

not very accurate info I can find on the internet because the parts are old. It's likely a zener diode so this part may be a suitable replacement:

http://ph.rs-online.com/web/p/zener-diodes/0508658/

you should be able to find it other places, or some other 16-22v zener, 500mW or close to those values. I would not go above 22v or below 16v.

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the 22 nomenclature on the existing part determines the zener voltage, and yes, it's to prevent a voltage spike from damaging the FET gate.

you might get lucky and all you need to do is add the part back in. i doubt you are using this for the highest level of competition, so it's not a big deal if it just works OK.

do either of them work as is? they should work without that part if it's just a snubber circuit, though repeated use will eventually damage the FETs.