This P1 Dolphin board has the Mach220 chip that’s seriously damaged and the main relay fet vaporized from the board. Both instances left some low impedance paths between some traces. The Mach220 removal solved many of them. But the fet traces are damaged inner layers of traces. So the fet will have to be isolated and jumpered back into the circuitry.

All of the power supplies work with the Mach220 removed. So now the debug process starts. With a massive pile of projects on my plate, I don’t know how much more work this board will get until I have more of the projects completed.

This is how the board arrived. The 5v rail powered this Mach220 to death. Amazingly the 5v reg still works.

Here is what a correctly removed Mach220 location looks like. Zero lifted pads or traces. A socket will get installed here.

This fet had to have been jumpered to try and operate the main contactors directly. This is what happens.

The board did not squeal when it was tested again. It works fine now.

The #4 IGBT driver on the 4th board had a bad opto coupler on it. Now it’s in line to be tested in a truck.

Now for the squealer.

Three of the P4 50kw boards booted up without issue. Their next step is to be test driven along with some other boards.

The 4th P4 50kw board has an issue with IGBT driver #4, so it’s faulting. Disconnecting the IGBT driver allows the board to boot fully.

The 5th P4 50kw board squeals when powered up. Been down that road before.

The 6th P1 50kw board has a crater in the middle of the Mach220. I’ve de-soldered a few of the 68 pin Mach220’s and put down surface mount sockets, but there could be some toasted traces too since it took so much power to damage that chip.

Powered up one of the 65kw boards. They use the J1850-VPW bus for communication, so I could not watch the activity on Buscom without a J1850 to RS232 converter. Plenty of these on the market to fix that. More than a level shifter is needed here apparently.

One of the boards that nearly boots up, Is showing an IGBT fault during bootup. It has an issue in the #5 IGBT driver.

This evening I tested 5 of the 6 50kw Dolphin main boards. Three work fine in initial testing. 2 nearly bootup, but fail. The sixth board has a crater in the middle of the Mach220 chip. I’ve replaced 2 Mach220’s in the past. So it will be easy. But the chance of some board traces being damaged is very high.

Today was all about cleaning house, so to speak. The spreadsheet that maps every component on the Main Dolphin board, is done. I also added many links for the schematics that cover the various circuits. It’s far more organized and quicker to look things up.

Due to the spreadsheet I found many differences in component values. This could help with the finding the dropout issue.

One thing I looked into long ago that I want to revisit is getting a board X-ray’d so that I can find out more quickly where the traces are going. If some are damaged an Xray may help to locate where the trouble is.

The 8 main boards arrived today. Not packaged well. Several took shipping damage. Sigh. Second time I’ve seen this. I’ll never understand why people don’t care about this valuable hardware.

The 65kw boards have completely different checksums for all 3 of the main IC’s. So they may not swap with a 50kw board. Once I get them running on the test fixture I’ll then swap the chips over to the 50kw boards to see if they will work at all.

Most of these boards are P4 revision. Which means they are the second generation with all of the improvements built in from the first generation. I’m running a P4 second generation board in my truck for close to a year I think it is, and it’s never ever had a dropout issue. That’s a clue unto itself. My new spreadsheet is helping me to uncover the dropout issue.

Owners of US Electricar vehicles take a chance with Chris Zach’s quality of work. In his own posts he mentions that he damaged 3 of his customer’s boards. Remember that these boards are NOT available new anywhere. I have never, ever damaged a customer’s Dolphin board. Chris has charged $1000 for a board, but claims his group is non-commercial in nature, so beware.

If you want some technical help email me at

mikep_95133 at

or join my US Electricar group at

I’ve spent about 6-7 hours tonight working on an idea I have for helping to find the cause of the classic dropouts. It’s tedious but will be worth it later. Here’s the details. I’ve made a map, using a spreadsheet, of the locations of every single component on the main board. That way I can search for the value of a component or for the component identifier itself. This effort’s biggest value is in comparing the first generation P1 board components to the P4 board components. So far the P4 board I’m using is more reliable in that it has shown zero classic dropouts after being operated in the winter and summer without a dropout.

This spreadsheet also will make it easier to find out where the DCN’s were applied. Usually, a DCN’s intention is to improve the operation of a specific circuit. So all of the components that are changed in that circuit would be part of one of the DCN numbers. This is standard engineering practice. If they followed it, then the DCN’s will not be hard to find and then document.

All of this will help identify why one revision of board is less effected by constant use, than another revision.

If you look on your main boards, some of them have decals on them that list 3
DCN numbers. That stands for Design Change Number. One of the 3 numbers is for a
firmware upgrade. The other 2 are for parts changes. This exercise will help me
to understand the even more extensive changes made to the 65kw boards.

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