Gaggia Vision Platinum Dead Grinder Resolved

This is another one of those issues with no answer as seen on coffee machine forums around the internet, so I thought I’d post this solution as it will help somebody. This is going to be a quick story about a dead grinder motor which when replaced with a good one, still does not work. The machine throws up the little spanner  and says “restart to solve the problem”. Don’t do it as it does not solve the problem, its a complete fabrication. If this is familiar to you and you don’t want to buy a new power board (assuming you can find one), read on.

Grinder failure gaga

I had not seen a Gaggia Vision Platinum before in the work shop. This one arrived on a day when I wasn’t busy, which was a good thing as it was a real pain. Getting into it seemed difficult but actually its bloody easy when you know how. The lid just pops off, in theory that is but this particular unit was stubborn and I did as the Russian guy demonstrated in a youtube video and took the sides and front off as well. Don’t do this unless you really have too. You know how Russians like to suffer and do things the hard way, like shovel snow by hand. It had also defaulted back to Italian just to complicate things further.

Anyway fast forward. Once I had removed the grinder I found the motor was dead (test it on a DC power source or meter it), although the grinder blades and mechanism were ok. I replaced the motor and also changed the little reed switch that counts the grinder rotations. This was not necessary but I had a spare one and felt like doing it.

To my shock the new grinder did not function, no voltage. I got the little spanner flag on the display again. Ok this will be easy I thought a FET or something dead on the board. The Gaggia like the similar saeco’s has a CPU board with all the logic (located in the front behind the display) and a power board. The power board is the one located in the top that the grinder etc plug in to. On inspection there was no apparent drive circuitry for the grinder. The element and pump had obvious drive components, not the grinder. I have no idea how it is switched on but I’ll find out.

So I pulled the board out anyway and tested obvious components (the ones I know how to test). I got lucky and found an open 5W 4.7 ohm resistor. See the photo below, you can’t miss it. Its the big white ceramic resistor. In the second photo you can see the one I got from Jaycars to replace it. Just a plug for Jaycars. Anyway getting to the point of  what this blog is really about. If you have this issue, don’t pay $170 for a new power board, meter the resistor and change it. If its not the resistor then its something else, does that help.

This resolved the issue on this machine and it was up and running again making surprisingly good coffee, although still defaulting to Italian. That was a harder issue to resolve, no the battery was ok. These machines have very good software so it is possible to go into a test mode and test components like the grinder, the brew unit motor and open valves etc. You can also get flow rates. I rate this machine and now I can get into it I’d work on them in the future. It is a shame parts are hard to find.
When I work out how the grinder is controlled I will post it here.