Hi.
June 2015. Hotpoint Aquarius 541 bought about 2008. Stopped working with all lights flashing. Based on the advice here I did the following.
Located the control panel with the C17 capacitor. On my machine, this was done by going around the back of the machine and opening the screws around the bottom oval shaped plastic cover/panel, the one where the hose comes out. The circuit board is enclosed in a white plastic case inside this hole and on the left hand side. You have to take off all the connectors. I took photos. However, the connectors are keyed with slots in the circuit board so would be hard to get them wrong. I did find the photos helped so really suggest you take photos. To finally get the white plastic case out, you have to undo a screw on the bottom left back on the outside of the machine itself. There is also a white soft plastic cover on the bottom left outside. Lever this off. Underneath is four plastic clips in an oval shape plastic holding type ring helping to hold the white circuit board case in place. These clips are released by sliding the plastic oval upwards. The metal hole into which the oval fits is wider when you slide it up and so the plastic oval just slips inside the machine. The plastic case with the circuit board is free to come out. (Note to reinstall push the plastic oval out through the hole from the inside and then slide it down). Once out, open the plastic case which is just held like a clamshell with clips. Having taken off the top cover, C17 is very evident, it is in the middle of the board and is marked C17. It is a 680 microfarad electrolytic capacitor at 10 volts. Note it is polarised so the replacement has to go in the same way. Specifically, the negative pin of the capacitor goes on the side of the Integrated Circuit (IC), i.e. the negative pin goes into the hole marked with a white round O around it. The capacitor itself will have a minus sign on the side to show which of the two pins is negative. Remove the circuit board from the bottom plastic clam part. Remove the faulty capacitor by unsoldering it and replace with same (I used a 680 microfarad at 25 volts). Reassemble in reverse. Mine seems to be working fine. Powered up, no red lights and machine is back on its first wash. I just wanted to thank all the good, kind folks on here who contributed and especially whoever worked out C17 was the problem. I am very grateful indeed and I hope the above may help someone else in turn.
Vincent S, June 2015