GenBoard/BuildProcedures/Stepper

This page is the checklist for GenBoard/VerThree with stepper driver chip

[SN754410NE stepper driver chip available here]


D45 options - OBSOLETE (since v3.3 stepper driver supply is connected with direct trace).

The "D45 southern pad" (referred below) is at the board-edge, 70mm from the left side. This goes to the 12V supply pin of the stepper-driver chip.

EC36-pin25 (corner pin of EC36, closest to the PCB edge, and closest the EC18) is the 12V mains supply. The advantage of using this pin (below) instead of the "northern pad of D45" is that the stepper current is drawn directly from the EC36 supply pin, and not going through the small fuse. Therefore the small fuse can be really small (eg. 450mA) providing really effective protection.

Chose one of the 3 according to your taste:

A: D45 is on the bottom side, between ec18 and ec36 below the F1 on the top side. - DB

TODO: picture


Burned stepper chip Question

Q: I have connected a vems to a 4 cyl Audi 1.8T engine.

If it is belongs to stepper, can i use the ecu via removing this chip, when using 34,36,24,10 pins?

Make sure the EC36/34,36,24,10 (or whatever used) pins match the ignition transformers, (IGBT or logiclevel) for YOUR controller (depends on options you purchased with), check [assembled controller webshop product page] that actually points to GenBoard/Manual/IgnitionOutput

Some experts on ChatViaIrc were trying to find out what's happening with your install, but totally uncertain of what ignition coils you have. Apparently [ICM delete] means using logiclevel outputs with logiclevel coils instead of the factory "Power output stage" + power-input coils.

But how did the logiclevel coils burn the stepper chip ? Assumedly power-input coils were used (that explains why stepper outputs got burned). Check the type of coil. To be sure please also measure resistance of coil pins (all combinations). If you find 2 pins (other than multiple-grounds) that have appr 0.3 Ohm between them (often same in both directions), than it's not a logiclevel ignition coil.

Thanx KevinBlack? for the clarifications.

If he otherwise has enough (4) power-IGBT outputs, it's definitely worths to try to remove stepper chip. (replacement chip not needed if he does not need the outputs). The other parts of the board survive in 80+ % of similar cases. If other parts also get damaged, it's very likely to show up anyway (eg. if cannot connect via RS232 port at all). With small chance it might not show up (even with thorough bench-testing), and cause insidious problems later. Although most drivers accept that small chance to live with, obviously it rules out any critical application (especially aircraft), needless to say.

Study [v3 retest-repair] for more options.

I would: