my ferroli optima 701 has eaten another pcb board 10 months this time?

Also i have search Radio Spares and the required relay is from RS 253-4151 will do the job nicely....

shane-mcr
October 2010

The relay chattering is caused by the half cycle rectifying circuit though a single diode. The large capacitor is used as a smoothing circuit. To make it more like dc to activate the 48v dc relay. Once this goes it doesn't smooth it out and you get more of variable dc wave, causing the relay to make and break at the relay tolerance level. A temporary solution I found is to put a piece of plastic between the relay ry1 and ry4 ( one relay going vertical and one going horizontal). PLEASE NOTE BE VERY CAREFUL AS THIS AREA OF THE BOARD IS MAINS PROTENCIAL 240V AC...

shane-mcr
October 2010

The chattering Relay is the one to the far right of the PCB and often looks burnt due to the sparks caused as it chatters. After much searching and testing I've managed to cure this fault for about £6.

The chattering relay is actually caused by a breakdown in the small blue capacitor located close to it. This can be replaced for about 20p with a 10uF 100v (or bigger) electrolytic Cap. Don't worry if the replacement is physically bigger, just bend the legs. This may cure the fault; if not and the relay's knackered, replace the relay with a 48vDC 8A double pole one. The SCHRACK original seems difficult to locate in the UK but I got a similar spec one off ebay for £5 and it works great.

Thanks to Mr Bardwell on Abbeydale Rd Sheffield & Hartley Electrical Repairs on London Rd Sheffield for diagnosing the capacitor as the cause of the problem. Saved me £'s! :D

Helli
March 2010