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MJLJ Repair?
Xtreme Kermit - 8/6/13 at 06:12 PM

Guys, I've just been round to a friends (I'll call him Unlucky Dan) to 'tweak' his megajolt map to find that he has had an 'incident' that involved a mains electric jolt going throught the chassis.

The upshot is that the Megajolt is fubar'd. Chip U2 looks like what is left of Krakatau...

Who is the best person to diagnose/repair or let us know if it is a write-off?


dave_424 - 8/6/13 at 06:26 PM

These two people spring to mind http://www.megasquirtuk.co.uk/ and http://baileyperformance.co.uk/


Xtreme Kermit - 8/6/13 at 11:01 PM

Cheers Dave, I'll pass on the info.

Ian


MikeRJ - 9/6/13 at 09:39 AM

It should be easily repairable if it's the earlier through-hole version rather than the surface mount (which is still repairable, just a little more difficult to de-solder and re-solder the parts).

U2 is a 'MAX232', which is the device that converts between the +-12v levels from your PC's serial port to the 0-5v levels for the on board microcontroller. This (or it's equivalent from another manufacturer) is cheap and easily available from almost any electronics distributor (or e.g. eBay).

However, if the MAX232 has been blown up to that extent, then it's entirely possible that it's also taken out the microcontroller U1, which is a 68HC908KX8 (for MJLJR Versions 2 and 3 anyway). This device needs to have a bootloader programmed into it before you can download the Megajolt firmware, so unless you have a suitable programmer you would need to buy a pre-programmed device from Autosport labs or one of their distributors. Worth replacing the MAX232 first to see if the micro is still ok.


paulf - 9/6/13 at 11:08 AM

I used to build afew of these and have most parts for the earler versions.
Processors are not available any longer but i have at leat one and a programmer so could sort that.
paul


Xtreme Kermit - 9/6/13 at 11:39 AM

It's the later surface mount board, so I guess repairs will be more difficult...


snakebelly - 9/6/13 at 12:42 PM

Sounds like it might be time for a Nodiz upgrade?