MS3 Loosing Sync

[poroos]

Hello! I bought a used Megasquirt 3 from a local guy. I installed on my car and burn the same tune I had for my 2nd car, both are running the same engine B18C on a mini cooper. The tune work perfectly on the other car and trigger is lock on solid. But there is some problem with this new unit, I can start the car up normally and it will run for about a minute and then it lost sync and die out. This happen every time I try to start it and it seem to die exactly at 1 min. I try to tune the VR pot but it doesn't help. Another weird problem with this new unit is that if I left the ECU on for ~3min it won't start at all, seem like it can't see crank / cam signal. When I swap the megasquirt from my other car, it start and run fine. So I think something wrong with the unit I just bought.

Sync error log


Things I tried:
-Reflash the firmware to 1.5 and 1.4.1 - problem still persist
-Check the Cam/crank signal with scope - Signal is clean and noise free
-Look for bad solder joint - Can't find any bad joint
-Tune the VR - doesn't affect

[poroos]

Got it fix by a local tuner. Problem was one of the pin of the chip wasn't solder on correctly and pop loose. He said that pin 126 wasn't solder on correctly on my board and it trigger a protection feature inside the firmware that cause the timer to reset and the trigger to loose sync. Pin 124,125,126 must be connected to ground.