RESOLVED: JimStim voltage issue.

[HidRo]

Everything is working fine, and then voltage drops.
On the jack I see around 16v almost.

on 3.3v it has 1.2v
on 5v, it has 3.3v
on 12v it has 4.4v

Recycle the power on jimstim, and it works again, then goes out again.
On TunerSTudio, it will kill the RPM, but TPS works.

What gives?

[racingmini_mtl]

Check if anything gets hot. By the way, didn't you just solve other issues with your JimStim? If so, are you sure the fix is still good?

Jean

[HidRo]

The only fix I did to my JimStim was the power led, that had a bad solder joint, but that is rock solid.
I did not change anything else.
The MAT will be jumping up and down, and I have no idea why. From my memory, MAT is solid when on the car, so, I'm guessing this is a JimStim issue, but was not able to track it down.

[racingmini_mtl]

If you unplug the MS from the JimStim and still get the same voltage values then it's a JimStim issue. Otherwise, not likely.

As I said, is anything getting hot? A low voltage usually means there's a short so you will have something heating up. In any case, remove the JimStim CPU and redo the tests. If you then have normal voltage, you found the issue.

Jean

[HidRo]

Following up on Radics1 questions offline, checked the voltage on the voltage regulator, after the issue starts:
1-2 legs - 2.4v
1-3legs - 3.3v
2-3legs - 0.89v

Also, F1 is getting hot.

[racingmini_mtl]

... remove the JimStim CPU and redo the tests ...

[HidRo]

I will try this, but one question.
This only happens after Jimstim is working for a while, and I can see everything working fine on TunerStudio.
Only after a while, this goes bananas...

[HidRo]

So, I tested this again.
The voltage drops with MS connected, without MS connected, and also, without the CPU.
When the issue happens, F1 (in Jimstim) gets really hot (too hot to touch), but if I touch it for a second, RPM will get back (tested blowing on F1 directly, and also gets RPM back to life).
WHen this happened, I removed JimStim from MS, and tested. A few seconds later, the voltage dropped.
Removed the CPU from JimStim, and the same happened, a few seconds later, voltage dropped.

I noticied that the voltage regulator get hot as well.

So, what do I need to test next?
Thanks!
Gonçalo

[racingmini_mtl]

Remove D4 (one leg) and check again.

[HidRo]

I did not have the chance to remove one leg of D4, but checking the voltage on the Voltage regulator, I see that the led will dim and brighten, and when it dims, the voltage at the 12v pins will be 8v, and when it brightens, it will be 13v.
Maybe the regulator is shot?

[racingmini_mtl]

It could be the regulator but you'd have a similar behaviour with a faulty diode. So try the diode first and then the regulator.

Jean

[HidRo]

Will do and report back.
THanks!
Gonçalo

[HidRo]

Resolved.
It was the voltage regulator that had a bad solder. Somehow the soldering is becoming nasty after all these years ahah
Resoldered it, and all good!