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Discussion Starter · #1 ·
Hi Guys ...... what would cause a motor to spin up to max revs as soon as you place it on the track??

Presumably some thing is not quite right ........ any clues???

Cheers - Greg
 

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If the motor spins up, then there's obviously power, so either the track wiring is faulty, if you haven't plugged in your controller or your controller is faulty, if its plugged in. If its an electronic controller, maybe a transistor has blown or if its a resistor controller there's a fault inside the controller. Without a bit more info, it's difficult to tell.

Just noticed you've posted in digital so anything is possible, there's more educated people than me on this forum where digital is concerned.

Mike T
 

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Hi Greg,

Assuming it's chipped, it's maybe the chip blown. My first saloon chip did this after I shorted it out while testing with temp wire connections and the chip fell out and the wires touched the live rails.

Cheers
Chris
 

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Thanks guys ....... time for some more information.

I am embarking on fixing my dead chips, my success rate so far is 5 out of six; 3 x F1s, 1 x Saloon and 1 x DPR. The sixth one burst into flames whilst I was testing Icar-Pro v3.0 for MIH. Here is the picture:
View attachment 9665
The NO2 mosfet was nuked so I replaced that one and the PO3 just for the hell of it. The diodes also had a makeover for some high amp ones with a forward voltage of 465mA


I was only half expecting this one to work and low and behold it didn't .......... it just revved up to full speed. This was more than it did before though
.

I was just wondering if there was anything else that could be done.
 

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Hi Greg

Lots of racing last night...In warm up session using Boxsters one of the cars took off on its own with no input from controller at full pelt...

Placed it on track today and still at full throttle..It has a saloon chip in it factory fitted with leds still on legs,looked at board but nothing seems to be showing as fried

Its sounds like the same problem???any ideas

Cheers MikeD
 

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Funny you should post this one... I was just about to post the same(ish) question.

I have a saloon chip that I had previously upgraded by replacing the diodes with some schotkys and replacing the two mosfets with the super MOSFET in the RichG post on the topic - it was to power up a chip for a SCX Seat cupra that seriously sucked juice to make it go. The upgrade worked a treat but finally "blew out" when the chip went 'full on'

I will post some photos of the blown chip soon, but I who uld be grateful for some thoughts on the matter...

Cheers

Andrew
 

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It sounds like the same issue I had here....Mind you that is for a "un-modded" chip.

I've tried the upgrade as well, and 2 out of 3 worked fine for me the last one did the same as yours....I guess somewhere along the line my soldering wasn't "petite" enough.....
 

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Quick up date

Placed car in freezer for 2 hours!!!!!!

placed it on track it ran very slowly but managed to assign it to another throttle position

Bingo all seems to be back to normal?!?!?

Any ideas

MIKEFI
 

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Righto ..... the wife's out, back in a minute!

OK ..... one chip in a bag hiding underneath the ice-cream ....
 

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no not chocolate .... but Raspberry ripple
............ anyway, two and a half hours in the freezer ............. didn't work!


However, don't let that stop the suggestions from coming in ..........
 

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Don't you mean whasberry whipple.......
Sorry It didn't work out for you......but thats one extra chip i do not need to buy......
 

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..... but that's not all. Armed with Ian's circuit diagram of the Saloon chip, I investigated some more. The NO2 mosfet drives a transistor and then the motor, whilst the PO3 mosfet is used to work the brakes in conjunction with the other transistor. Not being sure which was which, I canabalised another chip for the TR3 and TR4 components.

Fired up the test rig and the motor did not move
........... then I noticed the smoke


My conclusion is that the PIC controlled has had a jolly good rogering ............ but is was great good fun trying to sort it and my fine soldering skills has improved immensely.
 

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In my case, I have reflashed the firmware post 'fly away' and it still reprogrammed fine (which might suggest the PIC controller is fine(?)). The mosfets had previously blown (hence the upgrade) but the upgraded chip worked fine for a long time... then... 'away it went'
 

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I would.

Remove P03, to take it out of the equation, motor will run, but without brakes.

If that does not get things going and you have changed N02, then suspect the A8E transistors, sometimes a failing mosfet will take them out as well.

As has been said, if the chip can be reflashed than it's basically working.

However.. it is possible that it accepts an upgrade but one of the outputs that drives the A8E transistors has been blown, more likely if you have a failed A8E, at which point use the board for spares.

Rich
 

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Discussion Starter · #18 ·
Hi Andrew,

I've already asked that one and the short answer is no. That is why I decided to nick them off another known working chip to test my flamed saloon chip. Luckily the resulting smoke show was not from them so I was able to return them back OK.

Greg
 
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