ija

Jetpilot, thanks for volunteering to help. It's very much appreciated.

I actually enjoyed Erwin's excellent service in the beginning - he was able to stretch his schedules and shipped my delivery faster than he promised and he was always very responsive. Therefore the disappointment was even bigger when the troubles started.

Believe me, I know very well what means to provide these hobby stuff to people - noone reads manuals and many of us are not so technically aware. That's why I was very polite especially in the beginning even his first responses were very offensive. My understanding about the potential root causes developed during the (mostly one-way) email discussion with Erwin when I further investigated the PCB. Eventually I gave very clear error description to Erwin and I was actually blaming his Electronics design house about very bad design, not blaming Erwin. I asked Erwin to verify my diagnoses with his electronics provider. At this time I wrote that I'm not actually interested in to get any warranty replacement because the electronics quality is so horrible that I could not use it anyway. I provided the further information for him in order to enable him to understand the actual problem in design so that we could save some serious accidents in future. At the end I asked if he could somehow compensate my troubles: I left the ball for him. I would have been rather happy basically for anything, 50 euros or some spare parts for future needs, Or maybe just apologies. But no responses at all to the final diagnoses email but instead some further offences and statement that my warranty ends. Erwin is in "denial phase" to accept that there is design/manufacturing problem in the controller and refuses to accept any input. And I think people should know about the fire hazard hence my report here. See some comments inlined below:

Low voltage actually explains why you have so good success with the gear! Electronics has been designed so that controller voltage is within the operational specifications in such a case.
rc4flying: your 5.9V is also saving you: Zener shunt is not yet doing anything but the associated series resistor further drops the voltage and wires & connectors contribute also to voltage drop. Therefore your actual controller voltage is probably rather near to maximum operation voltage of 5.5V and not high enough to cause troubles. I propose not to upgrade to 2S LiPo....

It's actually 5.0 - 7.4 written now. It's a big news to me that 4.8 was preferred and we all know the reason now! Erwin indicates 2S LiPo is perfectly ok also in his video here:
https://www.dropbox.com/s/g5r3o8vymj...6_low.MP4?dl=0
It's rather common way in the industry to speak about nominal voltages (7.4V is nominal for 2SLiPo) instead of actuals so I wasn't worried. And Erwin has been stating 3S is the problem not my 2S. Anyway due to design everything above ~6.0V is real problem as then operational voltage of the controller is too high in any case.

Any of those using 2S LiPo?

Erwin indicated that it's not going to work with 2S: When I asked about weak performance with 2S from Erwin I received the following response: It seems to me that there are several versions of the brakes...

Like explained above I was not actually eventually after anything. Erwin wanted to charge me 50EUR for one controller board instead of warranty replacement. Eventually I'm not interested because I found out that the controller itself is so poor quality that I need to create my own solution anyway because I want to use 2S LiPo. Everyone who understands electronics well knows how high risk of uController malfunction is when VCC is significantly above permitted range. Of course I cannot be sure what got broken but I explained above the most probable scenario. Maybe this is not Erwin's core competence and therefore I asked him to verify the problem description with his electronics design house. No response...

There really is a very bad problem in the electronics but Erwin doesn't believe. I don't know if it applies to small batch or to every single unit but it's definetely important for Erwin to investigate it. Now Erwin has been made aware of this problem but he actively ignores it. This could eventually cause big financial hit to Erwin if he is not going to take any actions. Especially in US but also in EU product liability penalties will be very high if you knew about the problem but you didn't do anything for it. It's just matter of time when some potentially serious accident is caused due to this controller design (if this is with all the gears, not just small amount) and then Erwin may find himself at the court of law. AND our hobby is under loop of officials and they create new laws & restrictions all the time: we won't need any serious accidents to provoke further control. I want to minimize the risk of accidents regardless of the cause hense this thread too. Please talk to Erwin to take care of this issue.

Ilkka