MSefi.com read only forum (Jan.15,2018)

So I am building my first MS and I have it fully completed but I noticed after the Input construction and testing that I am no longer able to able to get it to connect to my computer. I was able to test the clock circuit and connected and saw it counting in the real-time variables.


I have triple checked all the voltages and the 40 pin and went completely through the connection troubleshooting. I do get a loop-back in HyperTerm & Mini Terminal. Any suggestions?

Try a port check test. To do this check, you'll need the program portcheck.exe, which comes with most MegaTune versions, including the one on the DIYAutoTune.com website. You'll find it in the MegaTune2.25 folder. If you don't have a copy, download it here:

http://www.DIYAutoTune.com/downloads/tu ... tCheck.zip

Power up the Megasquirt and connect it to your PC. You do not need to open the case and should not put the boot jumper in place for this test. Close MegaTune if it's running, and run the portcheck.exe program. When this program starts, it will scan the available COM ports.

If the port it's scanning is not connected to a working Megasquirt, or it's on the wrong speed, it'll say "No connection made." If it's on the right port and right speed, it will give you the version of the Megasquirt firmware that's on the Megasquirt. Note that some Megasquirt firmware versions will look like earlier versions with this test - for example, 029V identifies it as 029Q. This is for backwards compatibility.

If you get a port where it replies with "S" or something else that doesn't look like a firmware version, this port is probably a fake COM port that echos back everything that's typed.

Let me know what results you get.

Matt,

Thanks for your reply

This is what I am getting after doing a port check. Stim battery is good and I am getting voltages at the 40 pin.


COM1 Opened
9600 baud
No connection made.
115200 baud
No connection made.

1 valid port found.

Hit return when done...

Try a voltage check. 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: the small hole to the right of the larger three holes marked X11, X12, and X13, the top (non-banded) end of D20, the left leg of U5, and the left (banded) end of D12.

You should have 5 volts at the following points: the right (non-banded) end of D12, the right leg of U5, 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.

Battery Voltage 8.52
Small hole next to x11,x1,x13 8.5
Left Leg U5 7.76
Banded D12 7.74

D12 Unbanded 4.97
Right Leg U5 4.97
U1 pin 1 4.97
U1 pin 20 4.97
U1 pin 31 4.97


Thanks For you help

Your voltage looks OK. Try reloading the firmware. If you get an error message, let me know.

I tried to reload it using easytherm no dice.

There is no LEDs coming on or anything would this be a dead CPU?

The LEDs aren't particularly meaningful here. Have you tried reloading the firmware with the MS2 download utility? (It works very well for MS1 as well, and is easier to use than EasyTherm.)

This is what I am getting.

Thanks for all your help


Download failed:
Expected response "
Boot>",
but received this "".

Exception caught: 4

Is the boot jumper firmly in place? Sometimes you have to press down on it when you turn the ECU on to get a good connection.

Matt,

I actually have a CMOS jumper in place used to clear the BIOS on a PC so I am sure that it is jumper-ed. I checked it with a multimeter and it shows that there is a closed circuit through the jumper. I tried again and got the same results on the MS Downloader.

Thanks
Scott

Please check to be sure the downloader's speed is set to 9600; it defaults to 115200 and the MS1 will not communicate at that speed.

Matt is it possible for me to ship this to you for repair? and what would your hourly rate be?

Thanks

Scott

We are not set up to repair customer assembled MegaSquirts ourselves - I would recommend contacting Peter Florance at PFTuning, as he's one of the best guys at fixing MegaSquirts out there.