How to debug a completed unit?

Megajolt Kit assembly Question and Answers. Be sure to review the <a href="http://www.autosportlabs.net/MJLJ_V4_kit_assembly_guide">Kit assembly guide</a>

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nickj
Posts: 32
Joined: Sat Feb 17, 2007 7:52 pm
Location: Norway

How to debug a completed unit?

Post by nickj »

Hi,

just finished soldering together 3 Megajolt units and before I mount them in the boxes, I wanted
to verify that they were ok. I verified voltages at each step and all were good, but when I connect
them to the laptop now only 2 of them will communicate. The third just sits there.

Are there any further checks I can do to determine where there may be a problem, after the
voltage checks in the assembly instructions??

One possible odd bug in the controller software: The software allows you to change map values
on screen, write to controller and commit to memory, even though the unit and controller software
are apparently not communicating?

Nick

brentp
Site Admin
Posts: 6274
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Nick,

The primary test after assembly and voltage checks is to verify communication with a PC.

If you cannot communicate with the unit, check the components and related solder joints around the MAX232A and all of the 0.1uF capacitors around that chip.
Also check the proper installation of the oscillator- check installation orientation and solder joints. Also verify that you see a clock signal going into pin 10 of U1- with a regular DC voltmeter you should see about 2.5V.
Finally, do a general check around the board for bad solder joints, especially all of the pins on U1.

Regards,
Brent Picasso
CEO and Founder, Autosport Labs
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