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MS2 V3 on Megastim 2.2. No PRM or O2 input.

Posted: Tue Jan 26, 2010 2:43 pm
by nicad
Running firmware 2.891 on a MS2, V3 board. Testing done with MegaStim board V2.2 with 12v feeding it. The Stim board was purchased fully assembled from a supplier "confirmed works". I purchased the MS2 board from someone who had someone else build the kit for them. It is built for Ford EDIS ignition and GM Stepper ICV. They never ran or tested it.
I have gone over the board and checked all the joints and verified all the component placement that I can. Verified all polarized cap and Diode orientation. Cleaned off pretty much all solder flux. But, as always, I am not 100% certain that the board was built 100% correctly.
Jumpers I have verified:
Tachselect <-> Optoin
Optoout <-> Tsel
XG1 <-> XG2
IGN <-> JS10
S12C <-> JS9
D1 jumpered
D2 jumpered
IAC2B <-> JS3
IAC2A <-> JS2
IAC1B <-> JS1
IAC1A <-> JS0

I have done only the basic configuring in MegaTune.
What works from the Stim board (according to MegaTune Gauges): MAP, TPS, IAT, CLT, Bat voltage.
what does not work: RPM, O2. (With S1 and S2 in NPN, PNP, or NB, WB)
I have never seen any of the 3 LED's on MS light up.
when I power up the Stim board, only the IGN LED lights up on the Stim board.

I found a post where someone said to get his RPM to work he had to insert a 1k resistor between the Base of Q1 and pin 1 of U1 on the Stim board. I tried this, but still no change.

What should I do next???
Any help is appreciated!!

Re: MS2 V3 on Megastim 2.2. No PRM or O2 input.

Posted: Tue Jan 26, 2010 3:49 pm
by nicad
Never-mind. After digging deeper, it looks whoever out this thing together simply stopped at step #55. There are about 19 required components missing (that I do not have). I just figured they were for optional configurations that were not being used.

So yeah... I have bigger problems that no RPM and O2 signal.... :-( :-(

Re: MS2 V3 on Megastim 2.2. No PRM or O2 input.

Posted: Wed Jan 27, 2010 3:20 pm
by nicad
Update: I have confirmed that every component and jumper should be in place up to step #55, which should at least give me all inputs into MegaTune from the stim board. All of the capacitors and resistors are correct values-- the diodes and transistors are much harder to read the numbers tho to verify values.

Again, the MAP, TPS, IAT, and CLT all respond correctly in Megatune from the Stim board. I have tried powering the Stim board with both a 9v battery and a lab 12v regulated power supply.

I am not seeing any RPM response from the Stim board. Megatune shows RPM at 0 no matter what I try.
I measure a pot-responsive tach pulse when I connect a scope between battery negative on the stim board and the "Tachselect <-> Optoin" jumper on the MSII V3 board. So the pulse is being generated from the stim board. Where do I check next? I have a DMM and an O-scope to check anywhere on the board for signals.

The O2 sensor value is set to whatever position the pot is at when the board is powered up, but will not change real-time by moving the O2 pot. Is this normal? Is it because I have no RPM?
Please help! :) :)

Re: MS2 V3 on Megastim 2.2. No PRM or O2 input.

Posted: Thu Jan 28, 2010 5:06 am
by Matt Cramer
I'd check the configuration and settings. If you post your MSQ, I can have a look at it.

Re: MS2 V3 on Megastim 2.2. No PRM or O2 input.

Posted: Thu Jan 28, 2010 9:08 am
by nicad
Thank you for the offer to help. It would be great if it is just a software or firmware setting that I have overlooked. That would mean that my hardware is so ok. :)
This is my first attempt at all of this, so if you see anything glaringly wrong, please feel free to point it out!
.MSQ File should be attached.

Re: MS2 V3 on Megastim 2.2. No PRM or O2 input.

Posted: Thu Jan 28, 2010 3:08 pm
by nicad
It turns out my board had been damaged.
After looking at the schematics for the optoin line, I followed the problem to a broken PCB trace between D1 and D2.

Bridged the trace, and now I have RPM input and O2 response... so far looks like everything is responding as it should! :yeah!: