Our Valued Sponsor
OpinionsConsumer ReviewsGuides and How TosCoffeeGeek ReviewsResourcesForums
Espresso: Espresso Mods and Restorations
Repairing Rancilio S27 - help please!
Donate to Coffee Kids
Coffee Kids works with farming communities around the world, improving lives. Donate today.
www.coffeekids.org
 
Not Logged in: Log In to Postlog in
New Topics updated topics   New Posts new posts   Unanswered Posts new unanswered  
Search Discussion Board search   Discussion Board FAQ faq   Signup sign up  
Discussions > Espresso > Espresso Mods > Repairing...  
view previous topic | view next topic | view all topics
Author Messages
norwood27
Junior Member


Joined: 10 Jun 2014
Posts: 5
Location: Pittsburgh
Expertise: I love coffee

Espresso: Rancilio S27, Delonghi EC155
Posted Tue Jun 10, 2014, 10:34am
Subject: Repairing Rancilio S27 - help please!
 

As background on the machine, I bought this S27 in complete but known broken condition. It was being sold by a church cafe, whose new manager said she had found it in the storage room when she started work there. She said someone had said something about corrosion; for $50 including the two portafilters and a manual, I figured I couldn't go too far wrong. The plan was to get it working as a baseline, then take it apart and descale it thoroughly.

After bringing it home, I opened the case and found to my delight that it really didn't look too bad in there. I had been concerned that "corrosion" might mean a complete disaster waiting on the inside; instead, it looked pretty healthy for a 20 year old machine. However, the Procon pump had clearly seen better days. It had seized (and showed signs of, yes, corrosion!) and fallen off the bottom of the motor. We sent the pump off to JC Beverage for a rebuild, got it back a few days later, and hooked it up to the motor with great anticipation.

And.... nothing. Hmm. The pump turns freely now, as does the motor. I had initially suspected some sort of gremlin in either the motor or its capacitor, but a friendly local motor shop invited me to bring both down, and they worked just fine when given 120v on the bench. The technician also offered that the bearings sounded like they were in great shape - no funny noises. (This was also reassuring, since the bottom of the motor had looked a bit dirty.)

Getting out the DMM and poking around, we find that:

- The motor is getting 120v. (However, not at sufficient amperage, as we will see in a moment.)
- All 3 solenoids are getting 120v, and at sufficient amperage to drive them.

The contacts in the pressurestat appeared to have some oxidation, but cleaning them up did not affect things one way or the other, nor did (momentarily) bypassing it entirely.

Studying the factory wiring diagram further, I found that one of the solenoids (which Rancilio calls "electrovalves") gets power via the yellow and white wires, using the same ground wire as the motor (and everything else), which is the yellow and green one.  The motor gets power via the black and white wires. Since everything else linked to the white wires seemed to work, I tried swapping the yellow and black wires for a moment. (I wouldn't normally do that, but the circuit board appeared to have identical components running those two circuits.)

Sure enough: the motor started immediately and ran fine. Powered the machine down, returned the wiring to the way it had been, and here we are now.

This is why I conclude that the black wire is not supplying sufficient amperage: black-to-white measures at the proper 120v, but the motor doesn't turn.

Does this definitely mean that I should be investigating individual components on the control board? I figure that the board 'knows' it should be running the motor, hence sends 120v to it, and thus it isn't a sensor issue. Moreover, nothing else runs on the black circuit except the motor.

Nothing on the control board is visibly damaged, although that of course doesn't mean nothing is wrong. All 3 fuses on the control board test good.

Any help would be much appreciated! Thanks in advance!
back to top
 View Profile Link to this post
calblacksmith
Moderator
calblacksmith
Joined: 25 Nov 2007
Posts: 7,672
Location: Riverside, Ca, U.S.A.
Expertise: I live coffee

Espresso: ECM Vene. A1, La Cimbali M32
Grinder: Azkoyen Capriccio, Major
Vac Pot: 40s era Silex
Drip: Msl. Com. brewers
Roaster: gave it a try, decided no
Posted Tue Jun 10, 2014, 12:17pm
Subject: Re: Repairing Rancilio S27 - help please!
 

It sounds like you are pretty well versed in troubleshooting.
You are on the right track, the motor works so when you find the issue, it will spin.
The internals of the boiler, lines, flow meters, valves and heat exchangers will most likely need a good descaling but that has nothing to do with the motor issue.
It also sounds like a pretty good deal, slightly better than the one I got on my 2 group... $75 and a 1.5 hour drive each way to get it.
Just keep tracking the power back to the source. The pressurestat only controls the temp of the boiler so it is logical that it did not affect the motor.
There may be a relay with faulty contacts or something similar going on.
Good luck :D

 
In real life, my name is
Wayne P.
Anything I post is personal opinion and is only worth as much as anyone else's personal opinion. YMMV!

Feed the newbs, starve the trolls and above all enjoy what you drink!
back to top
 View Profile Visit website Link to this post
calblacksmith
Moderator
calblacksmith
Joined: 25 Nov 2007
Posts: 7,672
Location: Riverside, Ca, U.S.A.
Expertise: I live coffee

Espresso: ECM Vene. A1, La Cimbali M32
Grinder: Azkoyen Capriccio, Major
Vac Pot: 40s era Silex
Drip: Msl. Com. brewers
Roaster: gave it a try, decided no
Posted Tue Jun 10, 2014, 12:18pm
Subject: Re: Repairing Rancilio S27 - help please!
 

Mod note, moved to mods and restorations from espresso machines.

 
In real life, my name is
Wayne P.
Anything I post is personal opinion and is only worth as much as anyone else's personal opinion. YMMV!

Feed the newbs, starve the trolls and above all enjoy what you drink!
back to top
 View Profile Visit website Link to this post
norwood27
Junior Member


Joined: 10 Jun 2014
Posts: 5
Location: Pittsburgh
Expertise: I love coffee

Espresso: Rancilio S27, Delonghi EC155
Posted Tue Jun 10, 2014, 3:01pm
Subject: Re: Repairing Rancilio S27 - help please!
 

calblacksmith Said:

It sounds like you are pretty well versed in troubleshooting.
You are on the right track, the motor works so when you find the issue, it will spin.
The internals of the boiler, lines, flow meters, valves and heat exchangers will most likely need a good descaling but that has nothing to do with the motor issue.
It also sounds like a pretty good deal, slightly better than the one I got on my 2 group... $75 and a 1.5 hour drive each way to get it.
Just keep tracking the power back to the source. The pressurestat only controls the temp of the boiler so it is logical that it did not affect the motor.
There may be a relay with faulty contacts or something similar going on.
Good luck :D

Posted June 10, 2014 link

First off, sorry about posting in the wrong part of the forum. This is definitely turning into a restoration, so thanks for moving my post there.

Wow, a 2 group for $75? No, I think you definitely got the better deal - that's awesome! Did you have to do any work on it?

And oops on the pressurestat. What you wrote makes sense, given both the physics of it and the color of the wires to the heating element. I was starting to grasp at straws by that point.

Do you know if the blue items on the circuit board, near the point where the wires leave to head toward the motor, are relays? They're about the right size and shape, but efforts to google the markings on them were not fruitful so far. Or is a diagram of the circuit board available, i.e., with specifications for the items Rancilio put there?

Thanks again!
back to top
 View Profile Link to this post
norwood27
Junior Member


Joined: 10 Jun 2014
Posts: 5
Location: Pittsburgh
Expertise: I love coffee

Espresso: Rancilio S27, Delonghi EC155
Posted Mon Jun 23, 2014, 6:26pm
Subject: Re: Repairing Rancilio S27 - help please!
 

And... with many thanks to jpboyt, who kindly answered my PM with a valuable clue that helped me find the bug in the circuit, we have a working machine! Or had - I took it apart to descale =)

I have one quick question about the boiler as I disassemble it: two things (level sensor, and ?thermocouple?? for the heating coil) seem to pass through porcelain insulators, rather tightly fit, as they go through the lid. I have seen pictures of an S27 boiler lid with absolutely nothing on it. Do I indeed just remove these two things? And how do I get them back in place, then?

Thanks in advance!
back to top
 View Profile Link to this post
view previous topic | view next topic | view all topics
Discussions > Espresso > Espresso Mods > Repairing...  
New Topics updated topics   New Posts new posts   Unanswered Posts new unanswered     Search Discussion Board search   Discussion Board FAQ faq   Signup sign up  
Not Logged in: Log In to Postlog in
Discussions Quick Jump:
Symbols: New Posts= New Posts since your last visit      No New Posts= No New Posts since last visit     Go to most recent post= Newest post
Forum Rules:
No profanity, illegal acts or personal attacks will be tolerated in these discussion boards.
No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum.
No SEO style postings will be tolerated. SEO related posts will result in immediate ban from CoffeeGeek.
No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum.
Who Can Read The Forum? Anyone can read posts in these discussion boards.
Who Can Post New Topics? Any registered CoffeeGeek member can post new topics.
Who Can Post Replies? Any registered CoffeeGeek member can post replies.
Can Photos be posted? Anyone can post photos in their new topics or replies.
Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts.
Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
Don't suffer bad espresso
Package deals on the best machines from Izzo, Quick Mill, VBM, La Marzocco & more.
www.clivecoffee.com
Home | Opinions | Consumer Reviews | Guides & How Tos | CoffeeGeek Reviews | Resources | Forums | Contact Us
CoffeeGeek.com, CoffeeGeek, and Coffee Geek, along with all associated content & images are copyright ©2000-2014 by Mark Prince, all rights reserved, unless otherwise indicated. Content, code, and images may not be reused without permission. Usage of this website signifies agreement with our Terms and Conditions. (0.204288959503)
Privacy Policy | Copyright Info | Terms and Conditions | CoffeeGeek Advertisers | RSS | Find us on Google+