step #1 Buy a micromodule
step #2 wire it to a DB 37 pin conector
step #3 wire up a DB 9 pin : pin #2(txout) pin#3(rxout) pin#5 ground
step #4 power it up and connect to laptop.......
step #5 spend an hour trying to figure out why the stim wont work all of a sudden
step #6 replace stim CPU with a spare load code, everything works! play with it for a while and pack everything up for a work related trip
step #7 two days later, after it has been running on the stim for 2+ hours, attempt to hook it back up to laptop to see what the new TS looks like.
step #8 exactly 2 sec later notice that it quit working again, voltage regulater is hot and poly fuse kicking in again.
step #9 heave a big *sigh* and wonder just what the f@^k is going on, get wallet ready to order another dozen or so CPU's
step #10 post an easy to follow "10 step plan for frying a jimstim" on forum......
So what the heck is going on?
It worked for a coiuple of short sessions using TS after loading a couple different code versions ( just playing with it, out of town for work so just brought it along to play with ). Nothing got shorted, the bottom of the board is sealed. literally it had been running on the stim for 2+ hours, but as soon as I pluged it into the laptop it fried.
The only thing I can think of is that it was powered up when i pluged the serial cable into the laptop.
I am now convinced that the origional CPU was fried by the same problem, and not static discharge like I had previously though.
quite frustrating.
Jean, I will be ordering another couple of CPU's from you ( this is starting to get expencive ) but I would realy like to figure out what is going on before throwing another one in.
Thanks,
Joe
Yet another way to break your jimstim......
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Re: Yet another way to break your jimstim......
How are you powering the Module? and your laptop?
With the JimStim CPU out, what voltage are you seeing between ground and the CPU power pin (3) and what voltage on the "VREF" screw terminal on the JimStim.
James
With the JimStim CPU out, what voltage are you seeing between ground and the CPU power pin (3) and what voltage on the "VREF" screw terminal on the JimStim.
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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New users, please read the "Forum Help Page".
Re: Yet another way to break your jimstim......
first time it blew, stim was powered by a 12v power supply, was ~11.2 v when powered up, had used this PS for 100's of hours. this time when it blew the stim was powered by a vehicle accesory adapter plugged into my work truck (12.598v).How are you powering the Module? and your laptop?
Laptop is powered by a laptop power supply, first time was plugged into wall at work, this time its powered by an inverter i have plugged into the truck.
3.3194 on my Fluke 189, tested all other pins with RPM pots turned fully clockwise, voltage on them is never greater than 3.3194.what voltage are you seeing between ground and the CPU power pin (3)
4.9077vand what voltage on the "VREF" screw terminal on the JimStim
Thanks James
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Re: Yet another way to break your jimstim......
Nothing seems wrong there.
James
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
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Re: Yet another way to break your jimstim......
There may be a transient that goes above the 3.3V you're seeing when you plug the laptop in. That would be very difficult (or even impossible) to see without a recording scope. That shouldn't happen with the regulator and the caps but maybe one of them is marginal.
Jean
Jean
Re: Yet another way to break your jimstim......
Yea, stim has worked for a long time with no issues. All i can figure is that there is some kind of voltage spike that is intermittently hitting the CPU, but the strange thing is that there is no real connection between the stim CPU and the rs232 on the module....jsmcortina wrote:Nothing seems wrong there.
James
frustrating to say the least.