mega squirt no connection with lap top

[larry b]

port checker reads com3 opened 9600baun no connection made 115200baun no connection made 1 valid port found.I'v tried to connect using com port 1-4 and still no connection made how do I find was port was found?

[Matt Cramer]

At this point I'd see if the outfit that built the ECUs would be willing to check them under warranty.

[vincenthoulihan92]

Hi

I am new to the site. I am having bad communication issues with my MS1 v2.2 which I purchased from DIYAUTOTUNE.com.

I assembled the unit and it ran my engine fine on two occasions.

I tried again a week later and found that firstly when the ecu was powered up the injectors just opened (even when the engine wasn't on!), the engine failed to start but the ecu was still connected with the laptop (all info from engine still working) and the leds on the ecu flickered. Fixed a dodgy solder joint for one of the FETs (removed the CPU when soldering). When I tried to start again the ecu would not connect with my laptop , no leds came on when I powered it or when I was cranking and still no start!

I have tried the loopback tests with the serial to usb cable and that all seems good and same doing it through the PCB. On the laptop it says "No Response" when I try to test the connection in the settings for communication. I have the correct port selected (COM3) and a serial data rate of 9600 for the MS1. When I try use the port checker app, it makes the connection with port 3 and then says "No connection made".

I have been trying over the past few weeks with the trouble shooting guide on communications (http://www.megamanual.com/connect.htm#ms1) and still have not found the issue. There are no noticeable shorts/breaks on anything.

I have tried using alcohol to remove any excess flux from the soldering as this is a issue I believe where the flux absorbs water and shorts connections, but still no difference.

I have bought another CPU from DIYAUTOTUNE as I thought this may have blown but still the same issue.

I really do not know what to do now and there isn't much help here in Ireland for Megasquirt Any help from you guys would be greatly appreciated.

Any suggestions?

Thank you.

Vincent Houlihan

[Matt Cramer]

I'd start by checking for a short in the board. 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: 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

[vincenthoulihan92]

I am getting 12.82 V at the small hole to the right of the larger three holes marked X11, X12, and X13 and at the non banded end of D20.

I am getting 12.14 V at the left leg of U5 and the banded end of D12.

I am getting 5 V at all the other point you recommended to check (the right (non-banded) end of D12, the right leg of U5, and pins 1, 20, and 31 of the CPU)

Would the small drop in voltage on the 12 V system mean a short?

[Matt Cramer]

No, there's a diode with a small voltage drop.

Next step - try loading firmware using the boot jumper. If you get an error message, post a screen shot.

[Ollie8974]

Open the computer Bios, Check the serial port to see if it is enabled.
Enable the port. The computer should connect to MS.