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IMPORTANT: enter the case-INsensitive alphabetic (no numbers) code AND WRITE SOME SHORT summary of changes (below) if you are saving changes. (not required for previewing changes). Wiki-spamming is not tolerated, will be removed, so it does NOT even show up in history. Spammers go away now. Visit Preferences to set your user name Summary of change: [http://megasquirtavr.sourceforge.net/manual/Basics.Install.Mechanic.html [Manual: Basics.Install.Mechanic]] GND and GenBoard/Manual/DDFlyback are the most important things when playing with inductive loads, and several A current. It's very easy to ruin hundreds (or thousands) EURO of equipments with bad (or lacking) connections. Don't power anything until everything (possible without power) is tested. * GND5 must be connected with at least 3 connections (EC36pin5, EC36pin21, EC36pin32). Usually, EC36pin22 (according to our standard, on the v3.x board, EC36pin22 is connected during final assembly to EC36pin21 and with a 0.61mm2 brown wire to the GND5 near the IGBT-s) is also used for GND5. Connect EC36pin22 as GND5 if unsure. ** With ECM removed, on the EC36-wire connector, measure ohm between EC36-wire side GND5 pins (EC36pin5, EC36pin21, EC36pin32, EC36pin22) and the battery-. Must be very low, <=0.1 Ohm. Do this for all 3..4 GND5 connections. ** '''If all GND5 connections break''' (eg. loose screw, or something; in worst case, never been connected!) ''''during engine (or WBO2) running, there is a huge problem, the board can be damaged.'''. One reason we use many GND5 connections is that if one breaks, HW will not be ruined. The other reason is high current capability of output drivers. Output current can be especially high with many low-z injectors and many ignition channels. * GND must be connected as well. ** With ECM removed, on the EC36-wire connector, measure ohm between EC36-wire side GND pin EC36-pin26 and the battery-. Must be very low, <=0.1 Ohm The above means that GND and GND5 are connected hard in the harness (eg. at battery-, but other point can be OK). However GND and GND5 are not connected hard onboard v3.x (a weak, appr. 1 Ohm connection exist inside the TPIC6A259 aka. P259 chip). If GND and GND5 are connected hard onboard (eg. the GND-GND5 bridge that was applied for safety on unassembled v3.x until around 2005Q1 is not cut), the VR trigger signal can be noisy at very low RPM (cranking). ---- '''See also''' * GenBoard/VerThree/Installation * GenBoard/Manual/InitialTesting/VerThree * TODO: some pages have some ground discussions. Make those minimal and point them here. Maybe try search for ground in wiki ? Optional: Add document to category: Wiki formatting: * is Bullet list ** Bullet list subentry ... '''Bold''', ---- is horizontal ruler, <code> preformatted text... </code> See wiki editing HELP for tables and other formatting tips and tricks.