MS2 V3.0 jimstim 1.5. Step 23 zero, zip, nada

[tmoble]

hooked up to a 12V SLA battery. step 23, no nothing.

jimstim pilot light comes on bright when switched but not connected to MS. with the stim plugged into the MS the pilot light just comes very briefly, goes out. If I turn on the stim, get the bright pilot light, them plug in the MS the pilot light goes out immediately.

Is the MS maybe drawing too much current?

which pins on the board can I check to see if I've built a short to ground?

any other bright ideas? just shoot myself?

[tmoble]

I notice an anomaly. the jimstim seems to be OK pilot light lights up bright, has 12v at the 12v screw connector, 3.3 at the pin labeled 3.3. When I plug the MS in the 12v terminals/pins drop to 1.64. the 3.3 drops to nothing. The pilot light becomes very dim, apparently is getting the 1.6V.

on the MS board there's not 12V or 5V at the regulator at all.

the thing I have in U5 is marked "05ccd 231h48" is this right?

[slow_hemi6]

U5 should have LM2937ET-5 or LM2940CT-5 on it.

[billr]

Is the daughter-board removed, and you are powering the mainboard up to check voltages at the 40-pin CPU socket?

[tmoble]

>>> U5 should have LM2937ET-5 or LM2940CT-5 on it.

That's what I see in the instructions. I don't seem to have any such animal. Guess I better go thru all the bags again. BTW, google comes up empty on that number off the part.

>>> Is the daughter-board removed, and you are powering the mainboard up to check voltages at the 40-pin CPU socket?

never got that far. still on step23, checking the voltages.

Thx for taking time to reply, still need help.

[tmoble]

Found the bag in the bag of empty bags I keep from the build. it says:

(1) U5 +/-
Regulator LDO TO-220
LM2937ET-5.0

Doesn't look much like 05ccd 231h48

Dunno if this means anything or not. These numbers change a lot depending on manufacturer and vendor. Think I'll call DIY Auto-tune tomorrow and ask.

[slow_hemi6]

Looks like it is a generic version of the LM2937ET
http://www.msextra.com/forums/viewtopic ... 32&t=55030

[tmoble]

slow hemi, (are you a 426 or one of them new-fangled hemis?)

>> ...generic version..... Thanks for taking time. I searched and found nothing, I bow to your superior magic.

Any bright ideas?

For some reason the 12V rail on the jimstim is being pulled down to 1.6V as soon as the MS is plugged in. The power LED on the stim goes very dim but not completely out.

I think I'll pull the generic gizmo and try it like that.

One odd thing, I have a decent Fluke meter that has beep continuity test. Between pin 19 and 20 I get a brief beep. About a second, I'd guess. This is similar to the amount of time it takes the power LED on the stim to go out when the MS is plugged in. The troubleshooter part of me doesn't like coincidences.

Or maybe even a 392? A red-head? Do tell.....

[DaveEFI]

I take it the board is fully assembled but the daughter board not fitted? Did you build the Jim Stim too?

If using a SLA as a power source, do include a 1 amp fuse in a lead from it. Better to use a power supply that limits maximum current to this or less - as fuses blowing can be a PITA during fault finding.

Most likely cause of a short is a diode fitted backwards. Print out the V3 layout drawing, and go through them one by one, and put a tick on the drawing as you go. if you have a pal good at electronics, get him to do it too. A fresh pair of eyes can see something you've missed.
Check the tantalum caps are installed the right way round.
Then all the small transistors. Very easy to get a solder bridge at any of these. A strong light and magnifying glass helps.
Next - are all the mica insulating washers correctly fitted to the power transistors where needed?

It's possible you have a faulty component - but unlikely. Finger trouble is almost always the most common fault on assembly.

[tmoble]

ah yes, 10:30 AM in the UK? 2:30AM here. Thanks for taking time.

I pulled the suspect U5, it didn't make any difference at all. Re-inspected the whole board, one component at a time. Ima doofus once again. D11 was in backwards. Pulled it with some effort, it was in-between a couple other pieces. once out, the anomolous behavior of the power LED on the Jimstim went away instantly. reinstalled it and the voltage regulator and all is wonderful. the little truth table works with the pins vs. voltages correctly.

Moved on to serial comms. seems simple enough, but I'm getting local echo with no cable hooked up at all even though it's turned off in the config file ms2.ht

Parked it for the night. Supposed to up with my son at dawn to paint the interior of the 57 Chevy truck cab we're working on. That's less than 4 hours, dang.

[tmoble]

on another note completely, I got the 57 12V AM radio working. A guy in minnesota is an expert and sells parts. The vibrator goes bad, he's got a solid state version. Couple caps and Viola! it works. he's got a speaker too, hooked it all up with jumpers and a 66 El Camino antennae and sure enough, AM radio sounds as crappy as ever. But WTH, it works.

[tmoble]

And Dave, No, it wasn't all built. I stopped at step 23 when I couldn't get any voltage on the board.

[DaveEFI]

And Dave, No, it wasn't all built. I stopped at step 23 when I couldn't get any voltage on the board.

Excellent. Always follow the instructions fully. Fault finding as you go is always so much easier.

Over here, I was enjoying my mid morning coffee while you were burning the midnight oil.

[slow_hemi6]

slow hemi, (are you a 426 or one of them new-fangled hemis?)
Or maybe even a 392? A red-head? Do tell.....

In Australia the successor to the slant6 was the hemi6, 265ci inline 6 cyl. So yes I got a hemi, but not one of the fast ones.
Good job finding the reversed diode. Currently 11:30pm at my locale.

[tmoble]

Dave, sorry, somehow I thought you were in the UK. Even when I worked in mainframe ops at AXP I never could remember the time differences to AU/NZ.

I've never seen even a pic of the Hemi 6, is it vertical?

[slow_hemi6]

Here you go.
http://www.hotrodders.com/forum/attachm ... 1401516251
https://i.ytimg.com/vi/htHgs10AHXU/maxresdefault.jpg
I only have smallblock cars now. Still have the hemi6 but my block is toast.

[tmoble]

Hi again, got my issue fixed, continued the build per the instructions. Go to the part where I install the CPU, bring it up, install firmware, bring it up on TS, loaded the default tune, all appears OK. no action on any of the dials on the display, but that'll come with getting the rest of the board built.

One thing, during the bit where I loaded firmware, loaded a default tune, I never saw any reference to the .ini file. Did it get loaded automatically?

one other thing, I can't find any sample tunes besides the defaults. Didn't there used to be a place where a guy could find a sample for a 350 Chevy or whatever?

[tmoble]

OIC, finally. I've been using the instructions for assembling the regular MS2 board while posting questions in the MSExtra section. I didn't realize there were separate build instructs for the two. They're written differently but end up with the same result. The non-Extra instructs are much more detailed, which I'm comfortable with since I'm new at this.

Does anybody reading this know if there's any critical differences between the builds? I did load the Extra firmware and default tune.