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.

Some weeks ago I noticed that my scope had the #2 channel not working. It’s a Tek THS720. Nobody has touched this scope except me. Measuring the bnc connector impedance on the scope probe inputs, found that the #2 channel was at 1/2 meg ohms and the #1 channel was 1 meg ohms. Both should be 1 meg ohms. Something was up. So I took a brave step and took it apart. What makes this brave is that the scope is all solid state and portable. So it’s compact. Every step of the way I kept checking the bnc connector impedance. Right after I unsoldered the two short pieces of coax from the board, the bnc impedance went to 1 meg on the #2 channel. I could not see what the cause of this was. So after a serious inspection I soldered the coax leads back onto the board. The #2 bnc’s impedance was now at 1 meg. Sweet! When I finally got the scope reassembled, the #2 channel worked perfectly!! Man was I relieved! It appears it was just a bad solder joint. Although the solder was very nice when I inspected it.

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 yahoo.com

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.

I finally got around to putting fuses in the P12V_Bat and Key_On_In lines on the #1 truck. I tried to use 1/4 amps fuses, but the current drop was so much that the Dolphin would not boot. They measured 5 ohms on each fuse. I measured several and they were all the same. So I went with 1.0 amp fuses that measured about .3 ohms each. Very clean. I’ve done the same thing to the #2 truck. It was much easier to spend 3 minutes removing the junction boxes from the trucks and doing the work on a bench.

I also put a spring inside the 3/4 inch heater hose that was kinking. It now has a nice curve to it. The spring is just plated steel. We’ll see how long it lasts. At least this way the new high performance heater will always get adequate coolant flow to protect the heater element from overheating.

Here is the #2 truck Junction Box with it’s new pair of fuses.

« Previous PageNext Page »