m4 not firing??????????

tomaswatkins

hey lads put an 11.1 lipo in my gun today and was goin great i have it made well able to take it. Firing away and it stops. Checked motor conections and tryed diffrent batterys nothing. Not a sound like its trying to go either the mosfet made a few beeps aswel (its an active break). Think it could be the trigger switch. also the motor would not spin on its own and tryed diffrent motor but no good. i think the current is not reaching it please if you no anything coment
thanks
tomas:D

mafo

blown fuse or burned trigger switch contacts

tomaswatkins

thanks for the speedy reply! how did that happen to you reckon? that meen a new trigger switch? didnt use fucses so must be

mafo

Frequent single shots could lead to excessive contacts burnout, particularly in combination with 11V li-po. Clean the contacts with fine sandpaper, remove the fuse and use 7.4V li-po.

THE MINDER

Dont mean to to contradict mafo - he has a mosfet installed which should protect the trigger contacts.Assuming you checked the fuse and its okay you have a break in the wiring or faulty trigger switch-failing that maybe a problematic mosfet??

Rooky1

What make of mosfet is it?
If it is beeping at you, it might be telling you the problem.
Check your mosfet instructions to see what those particular beeps correspond too.:)

mafo

THE MINDER wrote: »

Dont mean to to contradict mafo - he has a mosfet installed which should protect the trigger contacts.Assuming you checked the fuse and its okay you have a break in the wiring or faulty trigger switch-failing that maybe a problematic mosfet??

You're right. I missed the part about the mosfet.

tomaswatkins

thanks for the replies lads. Opend the gearbox and as suspected no problems must be mosfet dont no enough about them. Does anyone no much about mosfets?

maciek87

Depending on how the mosfet is connected, you can always waste some time on disconnecting it, and try to re-wire replica - see whether its gonna go for you without it. You`ll eliminate than every single other possibility (as to the state of wiring etc.) - you`re saying you`ve opened it up already, but I would try to actually shoot from it as well.

Re-do wiring, than you can work out new mosfet/warranty replacement (as some brands give unlimited warranty for them).
You`ll need to provide some additional information with regards to the mosfet model and brand, and/or search for common faults/issues with them.

tomaswatkins

i disconected the mosfet and reconected it still nothing. Checked the wiring seems grand will ring the fella i got it off tomorrow and find the brand etc.:)

maciek87

Did you re-wire it? I meant, remove the mosfet completely from the circuit, re-wire back to original, manufacturers state...
I guess coming back to your man is better option anyway

tomaswatkins

didnt get a chance to rewire as in desoulder the mosfet ?

maciek87

Well, depends how its connected. Basically, the point was - remove the mosfet from the circuit completely, and try to use the rifle without it (wiring back to the original state)... re-soldering shouldnt take long at all...

Anyway, you still have that beeping from the mosfet - did you check that already?

tomaswatkins

i will unsoulder it at the weekend. The beeping stoped on sunday after beeping twice i will ring the man that put it in tomorow and repost:D

tomaswatkins

just after puging out mosfet and pluged in a regular tamiya and wires that are on standerd AEGs. pluged in a battery and without doing anything it started firing pluged it out imediatly and did it again same thing. should it do this????

glicster

yes that should happen.your aeg is connected straight from the battery to the motor but inbetween is the mosfet, kinda like your on off switch controlled by the trigger.youve removed your on off switch(mosfet) so when you connect the battery the juice goes straight to the motor fireing the aeg. does the mosfet have a fuse? maybe thats blown or id imagine the mosfets burnt out

tomaswatkins

thought that!!!! it looks like a yellow chip fuse and the filament looks like theres a piece gone ! might have fixed it! thanks lads!

tomaswatkins

is this yellow bit the fuse? looks like a broken bit in it http://imgur.com/DKREZ

Rooky1

Yep that is a blade fuse.

The same as used in cars/motorbikes.

glicster

yes thats it.there should be a number on the top of it to let you know what amp it is.and yes if the wire in it looks broke/burnt its blown and needs to be replaced.im not entirely sure but it should be just pull it out and push in a new one.
if a slight pull doesnt make it come out you can(of your own accord) peel back some of the black heatshrink and see how its held in and take it from there

but then you still have the problem of why it blew.maybe the mosfets not designed take the current from an 11.1v

Rooky1

Yellow is a 20amp fuse.

Link below gives you the info on the colour codes etc.
http://en.wikipedia.org/wiki/Fuse_(automotive)

Yours is probably a mini one.

tomaswatkins

just got it out thanks fellas for all your help will have it going in the morn

Rooky1

tomaswatkins wrote: »

just got it out thanks fellas for all your help will have it going in the morn

It looks very similar to a JG Mosfet unit.
http://www.evike.com/images/large/Gearbox_JG_Mosfet_M4_F_lg.jpg

I am not confirming it is that one, but looks very similar.

tomaswatkins

it does indeed il give Kris a shout tomorrow i cant remember what he said it was but twas a whill ago:)

Rooky1

tomaswatkins wrote: »

it does indeed il give Kris a shout tomorrow i cant remember what he said it was but twas a whill ago:)

Sure it doesn't really matter. Replace that fuse and see how it works then.:)

tomaswatkins

yup will do il have er spinnen in the morn

tomaswatkins

got it goin fellas thanks for all the help:)