Saeco Royal Professional. It has a false "grinder blocked" error. - Page 1
Forum section: electronics / repair

author: dupczyciel1
author_rank: Newbie
timestamp: January 19, 2023, 09:32:08 am
content: I get this error message. According to old post I cleaned grinder and out chamber - not helped. So I disassemble grinder to motor and cleaned once again - not helped. Grinder motor is working, after 2-3 sec of working machine stops with this error. Probably CPU doesn't get the signal that motor is okay. How does the CPU get this information, there is some sensor or there is current measure? Any ideas? Please help.

author: wraper
author_rank: Unknown
timestamp: January 19, 2023, 09:38:09 am
content: If it's a brushed motor with only 2 wires, then only current sensing is possible. Also note that if motor is still spinning, it doesn't necessarily mean it's OK.

author: Pfriemler
author_rank: Regular Contributor
timestamp: January 19, 2023, 12:36:12 pm
content: With the Saecos, the upper ball bearing under the grinder often gets dirty. The very stiff bearing then generates the error message via the current monitoring.Check in any case.

author: VeloSol
author_rank: Newbie
timestamp: November 04, 2024, 10:21:21 pm
content: Pfriemler, thank you for this!I had completely torn down and put back the grinder burr assembly and it hadn't solved the grinder blocked message, looking at the service manual (https://www.commentreparer.com/doc/13908/SAECO-ROYAL-service-manual.pdf) I was able to go into the service menu (from energy saving, press preground, medium coffee, small coffee all at once then tap Menu...maybe) it briefly displays the firmware version then shows input switches on the first line (eg dregs drawer, doser, brew unit presence, etc) and the second line will light as you press buttons. The buttons trigger doser electromagnet, grinder, brew unit direction, etc. This way I was able to confirm the motor (and attached burr) still moved OK.The automated cycle still didn't like it so I gently backed off the left-hand thread torx-10 head screw (ie screwed it slightly clockwise to loosen) and I was then able to pull shots again! Almost 24,000 coffees on this unit and this was the hardest repair (not that any of them have been too bad).The bearings and their tensioning springs can be seen athttps://imgur.com/a/UZfPoFzalong with the body underneath the lower burr holder. Be sure to vacuum up any coffee without vacuuming up the rubber shock absorbers before reassembly (the holder and springs go in then balls on springs then burr, nylon screw cap and lefthand thread screw.

author: VeloSol
author_rank: Newbie
timestamp: January 25, 2025, 01:08:48 am
content: Well, turns out that wasn't the (only) issue. The motor truly gave out after another day or two. I was lucky to source a new motor (no transmission) from AR Global Parts in eastern Europe but looking at the service manual it says 'motor will always be delivered with transmission'. Oops. The seller was able to help out with a how-to, you have to carefully remove the ball bearings at the top of the transmission (I think there were 31). Once you have most/all of them out the gears come apart really quite easily allowing access to the screws that hold the transmission to the motor.Then you have to get the drive gear off the old motor and onto the new one; I used a combo of strong thin screwdrivers, chopsticks, and colorful language to get the gear off without damaging the teeth. Pretty easy to get on to the new one.The transmission doesn't seem particularly sided but I did make sure to clock it relative to the positive and negative terminals (which were fun to get on/off, there's a small leaf-spring type latch that has to be gently and barely lifted to release and then remove towards the transmission) and keep that clocking when going to the new motor.I believe the motor coil failed open but I didn't make a note; certainly no motion when powered. Beware if testing a working motor out of its mounts; it will jump!A little food safe grease might help getting in/out of the shock mounts. I used the tried and true method of buying replacements so of course none of the old ones tore.