Megasquirt 1 V2.2 no power

[849charl]

Have had this megasquirt for a while, It use to run modded for MsNs , recently modded it for GM 7 pin HEI Module as per the manual. Tried bench testing it this morning by applying 12v (car battery) to pin 28 and ground to pin 18 but this time the LED didnt turn on. I dont know the first place to begin to diagnose this. Any help will be greatly appreciated. Thanks

[849charl]

Anyone ?

[slow_hemi6]

Post the msq that is currently being used in the ecu. Note as standard none of the leds are a power indicator. Are bench testing with or without a stim?

[849charl]

I am bench testing without stim.Applying 12v to pin 28 and ground to pin 18. I also have the MS connected via serial to usb cable. How to I upload a tune with the HEI settings if I cannot get the MS to power on.

Here is the tune on the MS now,

[849charl]

Also when i had the MS set up for MSnS, I powered it up the very same way and thhe LED's lite up, so i figured the same would be possible with the HEI mods

[slow_hemi6]

Okay that msq is not set up for hei, which is shown here http://www.msextra.com/doc/ms1extra/MS_ ... htm#gm7hei
The msq when opened shows MSNS for code type and HEI is off.
The LED 17 is set to squirt, LED 18 is IRQ trigger and LED 19 is acceleration.
You have no TPS or MAP connection so 19 won't illuminate, you have no tach pulse in so IRQ won't illuminate/flash LED18 and with no rpm there won't be any squirt on LED17.

[849charl]

I do have a new base map I made with correct HEI settings, how do I upload the correct map if I cannot get the megasquirt to power up in order to connect to tunerstudio and upload the new map ?

[DaveEFI]

[quote="849charl"]I do have a new base map I made with correct HEI settings, how do I upload the correct map if I cannot get the megasquirt to power up in order to connect to tunerstudio and upload the new map ?[/quote

If it won't communicate with TS, not much point in trying to load a new map. You need to sort that fault first. What doe the TS port checker say?

It's often a problem with the USB to serial adaptor. Do you know yours works OK? Have you got access to a desktop with a proper serial port? That would be the easiest way to check if it is a problem with the USB adaptor or PC USB driver for it.

[slow_hemi6]

You can also do the voltage tests indicated in James picture. Note processor is removed for test.

[849charl]

Thanks for the reply. I have to say that first and foremost i am not to tech savvy so bare with me. The serial to usb cable i had working fine a few months ago. I used it to connect to the current MS1 and got the tune off of it.

Can you explain to me how to varify the com port check in TS ?

Here is the map i created to fire up the MS with the HEI

[849charl]

thanks . Will check board for these voltages and will report back in a short while

[849charl]

I get 0v on pins 1,20,31 with processor removed, pins 2,19 and 32 also get 0v

[DaveEFI]

Right - you appear to have lost the 5v rail. Very careless. Just to be sure check at the proto area between 5v and ground ( both marked on the board.)

If that's not there either, check at U5 (that's the regulator at the top left hand side of the heatsink)

Pin 1 should read approx 12v
Pin 3 approx 5v

If 5v is present there, check either side of the polyfuse, F1, for 5v.

[849charl]

Right - you appear to have lost the 5v rail. Very careless. Just to be sure check at the proto area between 5v and ground ( both marked on the board.).

Is the 5v rail an easy fix ? Dont know where to get the 5v on the proto area but i did check the right side of r23 cause often times I have read that you get 5v there. When u checked there to ground I got 0v.

If that's not there either, check at U5 (that's the regulator at the top left hand side of the heatsink)

Pin 1 should read approx 12v
Pin 3 approx 5v.

I got 0v on all pins on the underside of u5.

If 5v is present there, check either side of the polyfuse, F1, for 5v.

Don't know where that is

[DaveEFI]

Sorry - the pic shown earlier was of a V3 board - I forgot you have a 2.2. So ignore the bit about the proto area.

However, if you've got 0v on all the pins of U5, you've not the 12v supply to it.

Find D13 by referring to the layout given in the manual, and check for 12v either side of it.

[849charl]

0v on top of D13 and 0.7v to bottom.

[DaveEFI]

0v on top of D13 and 0.7v to bottom.

Pretty certain the anode of D13 is connected direct to the 12v input pin on the D37 via a track on the PCB. So you need to check for continuity between those points. Is there any sign of burning on the board?

[slow_hemi6]

Also check at the supply terminals. If it is a smart supply and you have a short inside MS it may be shutting down it's output.

[849charl]

I see two burn traces. One from a hole coming off pin 1 of U5 to the bottom of D13 but I still get continuity, the other is from top of D20 to what looks like left side of C30, no continuity across this two points. You think soldering a wire to replace that burnt trace will fix it ? Will post a pic in the morning?

[DaveEFI]

If a component has failed short circuit, and you didn't have a suitable fuse in the supply to MS, there could be damage to the PCB in several places. But you have to find that short before repairing anything.

I'm not that familiar with the V2.2 to know the likely places so I'll leave it others who are.