looking for help fixing MS1 problem

[AkRev]

Alright, I had my brother in-law over helping me put the Z back together. After everything was ready to go I got in and turned the key. The Megasquirt did not turn on, I immediately turned off everything and noticed a small puff of smoke come out of the box. After going through all the wiring, this is what I found out; my brother in-law took the gray wire from pin #2 labeled IGN and thought that meant to wire it ignition.

 

Alright so here are the main details.

Running MS1-e 3.0 (worked five years ago before the car was put to rest on jack stands)

Power was on for about 3 seconds through the #2 pin before I turned off the key. (Dime size puff of smoke came out)

It is now wired correctly but MS will not turn on.

 

Really what I am looking for is some direction if anyone has seen or had a similar experience. I do not have a simulator board. Visual inspection of the board it appears that everything is normal. I will start going through http://www.megamanual.com/ms2/V3trouble.htm tomorrow. I am just looking if to see if I could get some pointers.

 

Also, I am sorry I have not introduced myself here on the forms, I will shortly, just trying to have a car to introduce.

[Matt Cramer]

To check for a short in the Megasquirt PCB, power up the Megasquirt on a Stimulator or on the car and check the following points for voltage with a multimeter.

 

You should find the same voltage as the battery voltage on the following points: S12, S12C, the center legs of Q9 and Q12, the left (non-banded) end of D3, the left leg of U5, and the left (banded) end of D9.

 

You should have 5 volts at the following points: S5, the two +5V holes in the proto area, the right (non-banded) end of D9, the right leg of U5, the left (banded) end of D19, and pins 1, 20, and 31 of the CPU.

 

Let me know where you find the correct voltages, and where you find the wrong ones.

[AkRev]

To check for a short in the Megasquirt PCB, power up the Megasquirt on a Stimulator or on the car and check the following points for voltage with a multimeter.

 

You should find the same voltage as the battery voltage on the following points: S12, S12C, the center legs of Q9 and Q12, the left (non-banded) end of D3, the left leg of U5, and the left (banded) end of D9.

 

You should have 5 volts at the following points: S5, the two +5V holes in the proto area, the right (non-banded) end of D9, the right leg of U5, the left (banded) end of D19, and pins 1, 20, and 31 of the CPU.

 

Let me know where you find the correct voltages, and where you find the wrong ones.

 

Matt you are the man, I will check those tonight.

[s30red240z]

Check all diodes, to be matched, the diode banded side with PCB banded printed (correct side)

[AkRev]

Alright, I get to own up to this one. First of all thanks for the help. The MS is fine, turns out that there was a burn on the board under the DB37, ended up nothing serious got damaged. During this whole process the fuse to my ignition blew and that is why MS would not turn on. (it is always the easy things that get overlooked)

 

Thanks again and sorry to waste your time.

[dexter72]

Its never a waste of time to ask for help,

 

It is a waste of time when you never ask for help. Happy Motoring.

[NewZed]

Alright, I get to own up to this one. First of all thanks for the help. The MS is fine, turns out that there was a burn on the board under the DB37, ended up nothing serious got damaged. During this whole process the fuse to my ignition blew and that is why MS would not turn on. (it is always the easy things that get overlooked)

 

Thanks again and sorry to waste your time.

 

So the battery had a direct short to ground through Pin 2 and blew the fuse? Doesn't the smoke mean that there is a damaged component?

 

I found this quote on the msextra.com site - "If you have any smoke then its likely you’ve put a diode in the wrong way round, this will mean finding it and fitting a new component. Once any component smokes it is no longer any use!"

 

Just trying to add a little to more to a my own limited Megasquirt knowledge. I don't know the pins so don't know what was on Pin 2 in MS1.

[AkRev]

So the battery had a direct short to ground through Pin 2 and blew the fuse? Doesn't the smoke mean that there is a damaged component?

 

I found this quote on the msextra.com site - "If you have any smoke then its likely you’ve put a diode in the wrong way round, this will mean finding it and fitting a new component. Once any component smokes it is no longer any use!"

 

Just trying to add a little to more to a my own limited Megasquirt knowledge. I don't know the pins so don't know what was on Pin 2 in MS1.

 

Sorry, I will explain better. It was pin #2 on the DB37. This is the shielding wire is labeled IGN on the harness. 12V power got connected to it and burned a small section of the board under the DB37 (about 2mm wide burn). As far as I can tell nothing else got ruined. The Megasquirt was assembled about eight years ago, and has always worked great.

I got the car started and seams to idle fine.

 

I plan on taking her for her first drive in about three weeks (got to get the rear end finished up)

 

I have not really posted anything about my car, and I know everyone like pictures, the first picture is my car back in 2001, and the second is close to how my car looks today. I will explain the story soon in the members projects forum.