Pasquini Livia 90S with dead control module (Fixed)

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
austinado16
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#1: Post by austinado16 »



Recently, I stumbled across a nice, one-owner, 2002-2005 Pasquini Livia 90S. It was being sold because it no longer controlled it's pressure, and an attempt at repair, had failed. It's arrived and I'm looking forward to learning about it, repairing it, and of course, making some espresso.

While waiting for it to arrive, I found a non-working Salvatore "Italia" SES grinder that I think will look nice along side the Livia. I laughed when it arrived, because it's literally the guts of an ASCASO 54mm flat burrs grinder that this guy (a boutique shop in the tourist community of Solvang, CA) has very crudely "re-boxed" into an internal fame of his own making, and a stainless metal skin that he bends up.

austinado16 (original poster)
Posts: 387
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#2: Post by austinado16 (original poster) »




The machine is completely dead, even though the photos on ebay showed it worked, except wouldn't control the pressure. I have the machine opened up and based on the wiring diagram I found here on HM (I added the current flow arrows), it appears the control module is dead. It is receiving 120v, and it's connected to the neutral circuit. It's also grounded to the chassis, and receiving it's 3 ground signals from the water tank, and boiler. For those of you who have worked on these, would you agree that's a dead controller? The previous owner had a shop replace the clear plastic control relay, the pressure stat, and it looks like both of the water flow control valves that have magnet relays on them, have also been replaced, because they are very new looking. The inside of the machine is in excellent condition, except it is showing a small crusty leak area at the bottom of the boiler. It's not bad though, and hasn't turned the machine into a giant corroded mess.

I've read in other repair threads here in HM that people are using a different control module. Looks like those are $255 plus tax on ebay. Is it better to rebuild this original one through the site that people are recommending? Or would that cost and wait time, not really make it worth the effort?
Thanks for reading!

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Jake_G
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#3: Post by Jake_G »

Hey Todd,

From the schematic, it looks like the relay and pressurestat are receiving their power from the "securezza" pin from the control module. The first thing that will shut you down is the tank sensor. You can check that by first ensuring there is water in the tank and that the probe is clean and able to read it. If that looks good but the machine is still DOA, try shorting the water probe in the tank to ground. This should appease the safety circuit and allow the boiler fill to kick in and send power to the pressurestat.

The boiler fill may not work either, but if the tank circuit is not satisfied, it looks as though the whole machine will appear dead.

Check that before looking into replacing the controller.

Cheers!

- Jake
LMWDP #704

austinado16 (original poster)
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#4: Post by austinado16 (original poster) »

Hi Jake,
I did have just normal city water in the tank, and did try grounding the wire on the tank.

Maybe I'm using the machine wrong, because I've never had one? I wound up jumping to the water pump circuit and then turning on the pump using the brew switch. I ran the pump until I had moved about 1/2 a cup of water out of the brew group. I assumed that that would fill the boiler, and then with boiler level switches (both are clean, bare metal) dipped in water, the machine might function. It didn't.

When you say; " ...allow the boiler fill to kick in." Does the machine NOT use the pump to fill the boiler? Does it somehow sort of gravity feed the boiler, by just the weight of the water in the tank, and that (what appears to be a )magnetic type of solenoid pulling a pin out of the water supply from the tank to the boiler?

I have the owner's manual and it says to fill with water, turn on the machine, and the orange light will come on...the boiler will be filled automatically and the water heated. It also says the green light will be on. My green light doesn't work. I did leave the machine just "on" and the orange light never came on, nor did any water appear to leave the tank.....until I jumped the pump and made water come out of the brew group.

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Jeff
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#5: Post by Jeff »

There is typically a solenoid valve that lets the pump fill the boiler rather than just pump out the group. The "three-way" solenoid valve connects the group to either the exhaust vent or the pump water circuit. It sounds like that one is working. The one that connects the boiler to the pump water circuit looks like L/A on your schematic. It will usually only have two ports on it.

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Jake_G
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#6: Post by Jake_G »

austinado16 wrote:Maybe I'm using the machine wrong, because I've never had one? I wound up jumping to the water pump circuit and then turning on the pump using the brew switch. I ran the pump until I had moved about 1/2 a cup of water out of the brew group. I assumed that that would fill the boiler, and then with boiler level switches (both are clean, bare metal) dipped in water, the machine might function. It didn't.
Ok. So the brew switch works. That's good, because it gets its power from the same controller as the pressurestat, just a different pin.

First, let's explore what you have on your hands. You have what's called a "heat exchanger" machine. As such, pulling water through the group head does not affect the boiler level, as all the brew water passes through the heat exchanger that is mounted in the boiler, but separate from it.

Next let's talk about the controller. It has two primary functions.
  1. Protect the machine if it runs out of water.
  2. Keep the boiler topped up with fresh water as needed
The sensor in the water tank handles the first part, and given the fact that the pump switch works, I suspect it may be working.

There are two similar sensors in the boiler that handle the second part and they might be working, too.

Before going too deep, I'd check the safety thermostat on the boiler and make sure it has not popped. It kills both the phase and the neutral to the element. If that looks good and if you have a multimeter, and are confident in using it safely, you can see if the controller is sending power to the pressurestat. If it is, great. You can the see if the pressurestat is sending power to the relay. And finally, if the power is making it through the relay.

The pressurestat is a simple set of contacts that will open when the boiler is making sufficient steam pressure, so when it is cold, it should have continuity across its contacts.

Hope this helps!

- Jake
LMWDP #704

austinado16 (original poster)
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#7: Post by austinado16 (original poster) »

Thank you Jake!

So to be clear, this machine is completely dead. I was only able to get the brew switch to make the water pump work, by removing the wire that would feed the pump, from it's position on the controller. I then jumped 120v (from the on/off switch) to that wire. I could then turn the brew switch on and off, which made the water pump turn on and off.

The green light doesn't work at all. The orange light doesn't work at all.

The previous owners made an attempt to repair the machine's original issue, which was that it didn't control boiler pressure and would just go up into the red and then blow the pressure relief valve. They had "someone" replace the pressure stat, and the big relay below the controller (the clear plastic relay). It almost looks like the 3-way water switch and the one that fills the boiler, have also been replaced, because they look so nice/new, but I can't confirm that. The inside of the machine is very new looking, so that may be why they look so good.

In the ebay ad from a couple weeks ago, they had photos of the machine working, and in speaking with them on the phone, they said that it could actually still be used, as long as you just turned it off when the pressure got to high in the green area...and that's how they'd been using it. They also said the green light didn't work.

However, when it showed up (it was packed incredibly well), it did not work. I filled the tank, turned it on, sat and waited, and nothing happened. No clicks from relays, no orange light, no green light, no pump running to fill the boiler (if that's what is supposed to happen upon start up?) Just completely dead.

I have a fluke meter and used that to test out the wiring, the grounds, test the on/off switch, test the brew switch, etc. It appears the controller is just dead somewhere inside, even though visually, it looks really nice everywhere on the 2 circuit boards (I popped it apart).

I guess part of my problem is that I don't understand how it fills the boiler. Can you explain that? Does the pump do that, with that first "L/A" unit clicking "on" and allowing water to flow to the boiler, instead of to the heat exchanger? That's how it appears it would work based on the wiring diagram.

In the diagram, it looks like the water pump always has neutral, and then receives 120v via the controller at position 7 (if the right conditions exist in the controller: Water tank level switch is creating a ground/Water level rods in boiler are reporting in) and the power is also sent to "L/A" during this same time, directing water to the boiler..........again, as long as water tank level and boiler water level "grounds" are reporting in. And then when the boiler water level rods report "full," the controller will cut off power to "L/A" and to the water pump, ending that filling cycle. The pump will then not work until the brew switch is turned "on" or until the boiler needs more water.

Is my understanding of this correct?

So what I believe I have, is a controller that doesn't output 120 to the pump, or to "L/A" or to the pressure stat and the green light.

Both rods in the boiler look brand new. There are no breaks in the green wires from them to the controller and they ohm fine. Same with the water tank level green wire.

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hankbates
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#8: Post by hankbates »

When the boiler fills the pump must run and the boiler fill valve must be energized to the open position.
If the boiler fill valve is not open and the pump runs then the water will first open the low pressure spring loaded check valve in the OPV assembly and send water through the heat exchanger to the brew group. If that path is blocked, then the high pressure spring check in the OPV will send water to the drain and limit pressure to about 9 bar, depending on adjustment.

If you have a Gicar control box, Pat Boyt at boytenterprises.com should be able to fix it for a whole lot less than buying new. If it is a Giemme, I'd still give him a try.

From what I have seen, most Livia 90s don't have a safety thermostat on the heating element, but I'd certainly check it.
Seems like Bezzera only supplied these for European markets

Hope this helps....
Some people rescue dogs and cats, I like to rescue Livias…

austinado16 (original poster)
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#9: Post by austinado16 (original poster) »

That does help, a lot, thank you!!

It has the original Giemme controller, and I mailed it to Pat this morning. It'll arrive on Sat. If I have to spend up and buy one of the Gicars on ebay, that's okay too.

It was tough to diagnose it without a really accurate wiring diagram, or current flow diagram. What I've posted in this thread, is all I could find online, and I have no idea if it's truly accurate. For example, it shows the safety thermostat for the boiler, but as you state, the Livia 90S doesn't have one. It also shows power leaving the controller at position 3 and feeding the green light, and one side of the brew switch at all times (I guess as long as parameters inside the logic circuit of the controller are being met), AND leaving position 7 feeding the water AND the other side of the brew switch. I don't understand that portion of the circuit, but 120v A/C wiring isn't my expertise (my background is automotive wiring diagnostics and driveability)

Something that's occurred to me today is that maybe when the previous owners had the machine worked on, who ever replaced the big power relay might have disconnected the wiring to the controller, and put the wires back on it, in the wrong positions. It seemed to match what the electrical diagram showed, but maybe I could have been more thorough in that part of the inspection. Too late, because the controller is in the mail. I labeled all connectors with a sharpie for what position they came off, base on the numbers printed on the actual circuit board. So I can make more certain when I get the controller back, that they are installed correctly. Maybe I'm just second-guessing too much.

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hankbates
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#10: Post by hankbates »

One thing Pat taught me was that if you are having crazy problems you need to both get all the wires in the right place, but also make sure that all the ground connections are good.
I have had really good results with Deoxit D5 (Randy Glass's suggestion), have used it on all sorts of electrical devices, from lamps to our old Volvos.
Be thankful your Livia 90 isn't the "auto" model with flow controller and touchpad. They (Model DE) seem to have far more electrical problems than yours (model PM, also mine).
Some people rescue dogs and cats, I like to rescue Livias…

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