Rancilio S27 electrical/computer problems

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
jgrosjean

#1: Post by jgrosjean »

Things were going so well!

After getting my machine working: Rancilio S27 - Restoration?

It's been working well for a few months. But this morning this happened:

1. It was dark
2. I plugged it in... power switch light illuminated
3. I flipped power switch on and when I did this I noticed that all green on indicator the lights in the control pad panel flashed for just a sec. I'm not sure if this always happens, or if I only noticed it because room was dark.
4. The main (boiler is full) green light also turned on as normal.
5. I went back to bed.
6. Came back to machine 40 minutes later and it was at temperature, but control panel to make water come out of head doesn't work.
7. I turned/on off a few times, and also notice that at some point green (boiler full) indicator light no longer turns on (orange light is also off).
8. I let it cool down and pulled the boiler water level sensor half way out. Turned machine back on.. and pump doesn't kick in as I would expect.

So what I have working is:

1. Machine turns on
2. Heating element boils water
3. Pressure stat regulates pressure

But not working is:

1. Control panel to make water come out of head
2. Hot water dispenser button
3. Green/orange boiler water level indicator lights are both off
4. Pump isn't turning on even when water level sensor is pulled half way out of boiler (so I know it's tip not in water)

Help! :( I feel somewhat confident messing with pipes and boilers after my previous restore work, but I have no idea about the this other part of the machine that seems to be failing. Any suggested steps on figuring out problem?

Jesse

jgrosjean (original poster)

#2: Post by jgrosjean (original poster) »

I did look over the computer board, and to my eyes I don't see any obvious problem. No burned looking area. And the three fuses all seem to still have a wire though them.

ira
Supporter ♡

#3: Post by ira »

Definitely measure the fuses with a meter, I've seen good looking fuses measure bad. Can you measure voltages on the control board under power?

Ira

Coffcarl

#4: Post by Coffcarl »

Hi, I can confirm that on my similar system all the green LEDs flash on the control pad when switched on.

So neither the below minimum (orange) nor the above minimum (green) lights come on. But the machine still heats up? I would have thought if above minimum did not come on then the boiler would not heat up as a safety.

Perplexing. My first guess would be that prior signals being sent to the GICAR, but the control pad, and maybe the level lights routed through control pad (?) Were not reflecting that. But pulling the level out halfway out to have started the pump in that case.

You have the other machine - swap components to test?

GICAR and control panel I would think. If there is a bad relay on the GICAR, the cost effective solution will be to identify the relay and solder in a new one.

jgrosjean (original poster)

#5: Post by jgrosjean (original poster) »

ira wrote:Definitely measure the fuses with a meter, I've seen good looking fuses measure bad. Can you measure voltages on the control board under power?
Thanks!

This was the problem, though it took me a while to figure it out. I measured the fuses while they were still on the board... one had about 10x the resistance, but I thought a broken fuse would measure at infinite so I thought maybe that particular fuse was just a different type. After looking at lots of other things I then looked again and noticed that the fuze was definitely burned out. When I took it out of the machine it measured infinite resistance... when installed I guess some electricity travels though some other route on board? I have no idea about these things.

Anyway good news is that after replacing that fuse the machine "works" again! Quotes explained in following post.

jgrosjean (original poster)

#6: Post by jgrosjean (original poster) »

Coffcarl wrote:Hi, I can confirm that on my similar system all the green LEDs flash on the control pad when switched on.
This was encouraging to hear! Gave me the energy to look at the darn thing this morning... and in the end it was just a fuse on the board. Looking at the board I also learned that there is a "programming lockout switch" on the board ... which I think might explain why I couldn't program doses. Haven't tried that yet, but good to know for future.

jgrosjean (original poster)

#7: Post by jgrosjean (original poster) »

"works"

Everything works again, unfortunately there's also a little extra.

The motor seems to activate on its own sometimes. Kinds sounds like it's trying to turn, but the pump is frozen... but that can't be because the pump and motor seem to work normally when activated directly... such as when I press a dispense button on the control panel. If I shine a flashlight through the side of the motor I can see that it's turning (fairly slowly) when making this noise.

Here's a movie of the problem. In the movie I am turning on the motor though the control panel twice. But you will also see a couple of times where the motor turns on by self. There's a good case of it towards the end of the movie.
Any idea what that might be? If the boiler water level probe wire was loose could it make this happen? (it did seem a little loose, but I tightened it and the problem still happens)

Coffcarl

#8: Post by Coffcarl »

I don't know, maybe this?

Rancilio S27 motor stays on

Wow though, for a rotary pump that sure is loud. As loud as my vibe pumps.

jgrosjean (original poster)

#9: Post by jgrosjean (original poster) »

Cross fingers... problems seems to have gone away...

Not sure what to make of it. But when I turned on this morning the problem didn't happen. I've had machine on for a few hours and problem hasn't come back. Pump only activates when I tell it too, or when boiler needs level up. Odd and not confidence inspiring, but espresso's are being made :)

I did get a NEW problem though, but just once and it hasn't seemed to come back either. That particular problem was that after being at pressure for maybe 45 minutes I walked over to the machine and noticed that it had lost all pressure. The pressurestat switch was engaged, but the heating element wasn't heating. The rest of the machine was working normally... I could dispense water, etc.

I turned machine off, flicked the pressurestat switch manually a few times, turned back on and all is working again. Not sure what to make of that... problem with pressurestat or heating element I guess? The pressurestat contacts are pretty worn, so I'm hoping that is it.

Question... where do I find replacement contacts for pressurestat? I have found a few pressurestat membrane rebuild kits, but they don't seem to include contacts... and I think I just need contacts.

Jesse

jgrosjean (original poster)

#10: Post by jgrosjean (original poster) »

Coffcarl wrote:Wow though, for a rotary pump that sure is loud. As loud as my vibe pumps.
Yeah, I think it probably needs a rebuild. It also drips slowly when running. I've just been delaying sending off for rebuild since it does seem to function.