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Old 09-17-2009, 07:14 PM   #201
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You're getting voltage, which makes me thing the NPN isn't turning on. It doesn't look like anything is backwards. Well, check voltage, then current, across the two pins for the jumper to the idle valve. You should see something.

Even if the valve polarity was wrong you should see something.
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Old 09-17-2009, 07:49 PM   #202
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Quote:
Originally Posted by AbeFM View Post
You're getting voltage, which makes me thing the NPN isn't turning on. It doesn't look like anything is backwards. Well, check voltage, then current, across the two pins for the jumper to the idle valve. You should see something.

Even if the valve polarity was wrong you should see something.
Ok, i pulled the jumper and checked for voltage, amps, or resistance. Im getting nothing. I think the NPN is dead. :(

EDIT: I have a spare TIP120 lying around that I bought from radioshack a while back. Im thinking of breaking off the current NPN and installing it in place, possibly route it with wires to the proto area.

Last edited by Marc D; 09-17-2009 at 08:04 PM.
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Old 09-17-2009, 08:07 PM   #203
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No reason to break it off, it can be soldered.

I'd suggest putting a volt meter on the jumper on the MS board, make sure the MS is putting out its signal. if you move the DC up and down you should see the voltage change from 0-5V. other thing to check is base of the NPN, which is the same point electrically.
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Old 09-17-2009, 08:07 PM   #204
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i.e. it seems the transistor isn't turning on.
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Old 09-17-2009, 08:18 PM   #205
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going to double check the voltage and try to change the DC.
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Old 09-17-2009, 08:36 PM   #206
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OK, so I checked the jumper wire that you gave instructions to solder, and it sits on pins "2-3" coming down on Q4.

At first, I checked the voltage, and it comes out at 0.30V. When I change the DC, the voltage remains the same. WTF.

Maybe I should try installing those Q20 and the Resistor instead of the jumper. It might have an effect.. Hell, I dont know anymore if the problem is with the MS or the adapter board anymore. Maybe there's a problem on the MS board.

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Old 09-17-2009, 09:11 PM   #207
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The resistor and second transistor are only there to limit current. I don't think it's going to be your answer. Jumpering over it just means more energy goes into the coil and less as waste heat in the resistor cooking your processor. :-)
It's only 1 ohm, it's main goal in life is to turn Q4 on and off.


Certainly it makes sense if it's not responding and there's no voltage there, that means the problem is likely with the MS internally somewhere. Things to check - try jumpering over R19.


Ok, it doesn't work at all, or it stops working after a bit? I'll assume not at all. It could be the transistor is overheating, but I doubt it.

If you really want to go all out checking it, take the "S5" or any 5 volt source in the MS, and touch it to the jumper. The 1k resistor in R19 will protect the processor. That should make it turn full on in a hurry. Tapping it should have the idle valve going crazy.

Have you checked yet what the MS *thinks* it's putting out? Idle valve duty cycle is something you can pull up a gauge for in MT.
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Old 09-17-2009, 09:12 PM   #208
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Also, check the resistance from the jumper to ground. First with the adapter board unplugged, then with it in. Perhaps in running one of the jumpers something got shorted or partially so. That would kill the voltage (0.3V) to the transistor and keep it off.
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Old 09-17-2009, 09:32 PM   #209
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Ok, i tried jumpering S5 to the idle area. The ms resets, but I can hear the IAC click. Looks like its a problem with the MS. Ill try jumpering R19 (the top portion) to the jumpered area correct?

If that doesnt do it, could the MS2 daughterboard be damaged?? Im hoping thats not the case, hell i havent even USED it yet. If that turns out to be the case, DIY is gonna hear from me.
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Old 09-17-2009, 09:38 PM   #210
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It's pretty interesting the MS would reset.

Yes,jumping R19, really, just over itself. Clip or solder a wire from one side of it to the other.
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Old 09-17-2009, 09:39 PM   #211
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I wonder what's going on here - I wonder if there's some settings or something. It's pretty frustrating without a stim or an oscope.
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Old 09-17-2009, 09:54 PM   #212
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Alright, I think Im getting somewhere with this.

The top, no matter what DC i set the MS at, reads at 0.30V. Im thinking a trace/resistor value is damaged or incorrect here, because...

On the bottom end of R19, as the DC changes (as you describe it) the voltage moves along up and down 0-5V. I set a strong slope to see if i get a serious change in voltage. I set the "current" temperature on the table at 90% DC, and then the next temp reading at 5%. The voltage jumps to 4.17V on the bottom portion of the resistor, and the top portion remains at 0.30V. Then as it moves closer to a smaller DC, the voltage drops significantly.

I think we found our problem.

So are you suggesting that I jumper R19 across and forget the 1K resistor all together? Or should I snip the lead to the top of R19 (as it seems to have a problem) and jumper that to Q2/3?

If we bypass R19 entirely, is there a possibility that the MS may become damaged in the long run from voltage spikes or the like?

Last edited by Marc D; 09-17-2009 at 10:12 PM. Reason: Added some info.
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Old 09-17-2009, 10:12 PM   #213
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I feel weird doing this. :-\


Um, just bridge across the resistor, even an aligator clip with do. First see what that gets you.

You could leave out D8 if you want, desolder or clip it, you're not using it. It does seem like the transistor is sucking all the current away, but, that's only 3 mA which sure isn't much. Do you have any high quality pictures of both sides of both boards?
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Old 09-17-2009, 10:15 PM   #214
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Check the resistance, with the adapterboard unplugged, from your jumper to ground....

i.e. If when you put in your jumper, it shorted to R39, that's a problem.

If it's not shorted, plug the board back in and (with the car off) make the same measurement. That should tell us the state of the transistor.
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Old 09-17-2009, 10:18 PM   #215
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Yea, sorry to ask yu with help on this, its not even related to your board anymore. (at least I think its not) Which transistor would be draining all the power? FOr the idle circuit, the only transistors that are in line would be the one on your board, but if that is sucking the circuit dry, maybe something is wrong with the transistor. Ill go ahead and jumper then to see what i get. I hope I dont damage teh processor.
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Old 09-17-2009, 10:22 PM   #216
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Please measure those resistances. That's the best thing you can do. when the board is unplugged, it won't matter, when it is, measure it both ways (swap + and - probes)
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Old 09-17-2009, 10:33 PM   #217
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I'll measure them soon, i gotta make a quick errand then ill be back. Ill let you know the out come then.
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Old 09-18-2009, 12:42 AM   #218
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Ok, what the hell.

I checked the resistances to see if there was any grounding or shorts from the board. Nothing. Weird. I then hooked up the board to see if there are any resistance/grounding changes. Nothing, i couldn't even get a reading. This is with R19 jumped, touching the jumper with a DMM, and grounding it out.

But had the craziest idea (probably not a good one but hell). What if I tried to just leave it jumpered and start my car with it?

Whaddayaknow. It idle works.. Ummm? So what should I do from this point? You did mention that R19 is required to protect the processor IIRC. Should I ask the guys on the ms forums about this problem?
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Old 09-18-2009, 01:00 AM   #219
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Ok I checked again the resistances one more time to see if I would at least get a reading.

Im using a lousy HF DDM, but it works. Anyway, I double checked the jumper with a ground to see if I get any readings. With the board disconnected, I get no readings whatsoever. Dont know what thats supposed to mean.

When I hook up the board, I get a lot of random readings of 10-170ohms for a split second, then no reading. I dunno whats going on. Maybe my DDM is crap, but when i measure the voltage of some things and resistors to double check, it works good.

So bypassing the R19 resistor allows the idle to work, but I dont know why in the first place. Im thinking just saying "**** it" and jumper it without that resistor in place. But I'm worried that I may damage the MSII CPU over time. I think it might be a good idea to check with the MS gurus over at MSextra about this one.

Maybe the transistor is drawing too much power? who knows. But jumping R19 and bypassing the resistor all together makes my idle work.

To the other guys what are using abe's board:

It would be great to have input/feedback from other people using abe's board. If it all checks out on abe's board and everyone else's MSII set up, then its safe to say that my MS board may be faulty somewhere, or just the resistor is fucked up or something. I might have a spare resistor to replace the other one, but I dont think it will make that much of a difference.
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Old 09-18-2009, 04:13 AM   #220
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Well, I got this response from Jean on the MSextra forums:

"Not knowing what is on the external board (circuit and components) it's very difficult, if not impossible, for anyone to help you. You need to talk to Abe because the issue is on his board (or on how you connected your MS to it).

Having said that, connecting a transistor directly to a CPU pin without some sort of current limiting resistor is a good way to damage your CPU."

Great. So theres something going on with that transistor, or that specific trace. I highly doubt that the trace on that board is bad, but theres something going on with that specific transistor, maybe sucking too much current. Should I swap out that J13007 resistor for a TIP120 resistor?
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