Thanks Philippe for the update.
I can't remember where HK said they will not provide support. Instead they told a forum is going to provide help on rchouse.com, and in fact very few answers there from HK but mainly from buyers, and in addition the web site is almost useless (performance, presentation ...)
In my situation i manage by reading content and asking question in forums to educate myself enough to do problem determination. I found first a problem of condo soldering on the RAMP 1.4 (bought a new one) then the pololu and finally arduino card died almost. I asked for a replacement of both (around 50$) but after 6 weeks while HK told me the supplier is going to answer, they said the supplier gave NO answer. Which means this product has no guarantee.
I sent it back waiting for their technical analysis and decision either to send a brand new one, tested and validated (i think electronics components are very bad ... excepting motors).
It cost me 60€ to send it back, they are compensating with 10$ in bonus point.
I expected better support from HK company. That is my point.
Pierre