Help needed Megajolt has stopped working

Steve d · Post by **Steve d** » Wed Oct 14, 2009 2:30 pm

Over the weekend I fitted my megajolt to a other car.

It powered up ok. But would not talk to the laptop, and the car was running on the edis not the megajolt.
I have looked in side the unit and the Ic1 uln2003 transistor had burnt out, which I have now replaced, Still had no joy in getting it to work. I have now replaced U1 and U2 but still no joy. I have checked the voltage outputs as per the assembly guide and all would seem ok.

Hope someone has a idea as to why it is still not give a signal out to the edis or the laptop.

Thanks

Post by **brentp** » Wed Oct 14, 2009 3:11 pm

Hello Steve,

Sorry to hear your problems. Some questions first-

Are you running a V3 or V4 controller? MAP or TPS version?
Was it working prior to you installing into the new vehicle?
How could you tell the ULN2003 was burned out- was it visibly damaged?
What features of the MJLJ are you using- User Outputs? TACH_OUT?
Which connections on the Molex connector are you using- can you double check the pins are wired into the correct destinations in the car's electrical system?

Steve d · Post by **Steve d** » Wed Oct 14, 2009 3:27 pm

Hi

I am running V4 controller and a MAP version.
The unit was running before great.
The ULN2003 was visibly damaged.
Only using the tach out.
The wiring is all ok as we tried a friends megajolt which worked fine. On the megajolt which stoped working we did connect a tach to it, on the second megajolt we did not connect the tach and had no problems with that one.

Hope this helps

NITROPIXIE · Post by **NITROPIXIE** » Wed Oct 14, 2009 8:31 pm

What make/type of tach did you connect and how did you make the connections??

The ULN2003 should buffer the signal between the processor chip and the tacho. If you have wired in the tacho incorrectly then you may well have fried the 2003 as you rightly said you have. It should protect the processor chip from harm.

What advance is the engine running on, is it the set 10 degrees like in limp home mode?? or does it vary with load and rpm as it should??

You could try reloading the firmware and see if this helps if problems persist.

Steve d · Post by **Steve d** » Wed Oct 14, 2009 8:44 pm

The tach is a standard Rover Mini 3 clock tach. In the other car it was running on a aftermarket tach with no problems.

The advance was just on limp home mode, if you disconnect the megajolt the car just stayed the same.

How do I reload the firmware?

Thanks

NITROPIXIE · Post by **NITROPIXIE** » Wed Oct 14, 2009 8:49 pm

I shouldn't of thought the mini's tacho should cause a major problem to be honest. Sorry just reread some of your earlier stuff and you did say it was running in limp home mode.

To reflash the firmware go to

http://autosportlabs.net/MJLJ_Firmware_ ... x_hardware

making sure you choose V4 firmware obviously.

Hope this does the trick

Steve d · Post by **Steve d** » Wed Oct 14, 2009 8:54 pm

will try and let you know thanks

Steve d · Post by **Steve d** » Sun Oct 18, 2009 3:10 pm

still no go.

NITROPIXIE · Post by **NITROPIXIE** » Sun Oct 18, 2009 3:24 pm

Bad to hear there is still no luck so far!!! how far can you get when trying to reflash the firmware??

Are you definately getting 5v at the voltage regulator and on pin 1 of the processor chip

What is the voltage at pin 4 of the processor?? should be around 2.4V. This shows a signal from the oscillator.

Post by **brentp** » Sun Oct 18, 2009 3:35 pm

Steve,

when you say 'still no go' - can you elaborate? What were you observing with the firmware programming software- were you able to flash the firmware? if not, what was the error message?

Also- with the ULN2003- if you are only using the tach_out *and* the chip appears burnt out, it was likely the chip was overloaded somehow.

How is it wired to the tachometer? Is the original coil still in the car? if so, is the original coil still connected to the tachometer as well?

Steve d · Post by **Steve d** » Sun Oct 18, 2009 7:03 pm

I was unable to flash the firmware as the computer can't see the megajolt. The coil was not on the car when we fitted it. Will test the voltage supplies in the morning and let you know the results. If I need a replace all the chips can I get them from here.

Thanks for your help so far.

Steve d · Post by **Steve d** » Sun Oct 18, 2009 7:37 pm

The voltage outputs on the voltags regulator are left = 4.95 mid = 0 right = 7.66, I have the megajolt conected to 9v battery, on the U1 as per the assembley guide I have 4.95 on pin one and ground as the photo. The voltage from pin 4 if I have it right is 4.91 volts. Hope this helps

NITROPIXIE · Post by **NITROPIXIE** » Sun Oct 18, 2009 7:50 pm

Now i'm pretty sure it should be around the 2.4v mark. Are you able to get hold of an oscilloscope to double check there is a 16MHz signal coming from it?? Its important as the processor chip wont clock.

When reloading the firmware did you go through the old DOS window with the power supply disconnected and then apply power when you get

c:\mjlj>hc08sprg.exe COM1 mjlJunior_V3.2.1.s19
Waiting for HC08 reset ACK...

then after you apply power you should get

c:\mjlj>hc08sprg.exe COM1 mjlJunior_V3.2.1.s19
Waiting for HC08 reset ACK...received 0xfc (good).
Calibration break pulse sent. Count: 1
Bootloader version string: KX8-IR
Available flash memory: 0xE000-0xFC7F
Erase block size: 64 bytes
Write block size: 32 bytes
Original vector table: 0xFFDC
Bootloader user table: 0xFC80
Bootloader data (hex): 82 80 00 00 00 66 20 f3
Are you sure to program part? [y/N]: y
Memory programmed: 100%

Or are you lost at this part????

Steve d · Post by **Steve d** » Sun Oct 18, 2009 8:27 pm

computers have never been my thing really. I am lost