Rocket Giotto Premium Plus won't start - Diagnostic help appreciated

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gahobbsau

#1: Post by gahobbsau »

My Rocket Giotto Premium Plus will not start up.
** Question: What are the possible causes and how do I diagnose? **
Of course I could take it for service, but where is the discovery in that?

Description:
a) Last time it worked, I turned it on and after about maybe 5 seconds, the indicator lamp went out and all indications of action ceased. My response was to turn the power switch off for about 5 seconds, then on again - thence it worked just fine = poured a long black and steamed a little milk for the mac, then a little clean-up and turned it off.
b) Next time for coffee, turn the power switch on and no signs of life.

Dis-assembly:
a) I have all the covers off the machine and have disconnected the cable connectors from the controller box and can slide the controller boards in and out of the box.
b) I have previously changed the indicator lamp, when the previous lamp stopped working.

The following thread offered some diagnostic guidance but my wiring is more modern as per the wiring diagram that is shown below. Similar guidance for testing with a mulitmeter and which referenced my wiring would be appreciated. ECM Giotto diagnosis assistance needed - no green light
Guidance would also be appreciated for the most likely faulty components.

Details about my machine that may help are as follows:
Model: Rocket Giotto Premium Plus
Age: About 20 months
Scale: None - RO Filtered water used
Controller box model No: A190004542
Board manufacturer: ProElind
Pressurestat: Sirai
Voltage: 240v
Cable connectors are modular female, one green (240v power side) and one black and appear to be more modern that those pictured with the wiring diagram.

WIRING DIAGRAM that matches my machine follows

Thanks in advance for all and any assistance provided and interest in my problem.

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Randy G.

#2: Post by Randy G. »

Have you done any testing at all with the voltmeter?
- Does the power switch work? Have you tried rapidly and repeatedly turn the switch on and off (unintentional "The IT Crowd" reference)?
Are you getting voltage across the Hot and neutral output terminals of the power switch?
Are you reading the same between the Brown wire at the controller box?
- Some machines shut down in certain circumstances:
Check the connection for water level sensor at the reservoir. either disconnecting or ground that wire should cause the machine to think there is water there (I do not know how that switch works).

I would think (hope) that a machine that is less than two years old would not have any corrosion problems on connectors.
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homeburrero
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#3: Post by homeburrero »

Randy G. wrote:Have you done any testing at all with the voltmeter?
Although it goes without saying, I'll say it anyway --
Working a machine while plugged in is potentially very dangerous. You have to know what you're doing, be very aware that two hands with access to a 240V potential can kill you.

Ideally you will want to first troubleshoot what you can with the machine unplugged, checking continuity rather than voltage. You can often discover simple things like a bad switch this way.
Randy G. wrote:Check the connection for water level sensor at the reservoir. either disconnecting or ground that wire should cause the machine to think there is water there (I do not know how that switch works).
Yes. That's a possible problem that would cause your symptom. First make sure the green ground wire off the controller has a good connection to ground. If that's good and it still doesn't work, then try disconnecting the wire that goes from the controller to your reservoir sensor and reconnect/ground it somewhere on the chassis (ground it so that you're sure it's got good continuity with the green ground wire to the controller) then plug the machine in and see if it works normally. If it does, then your prob is with the reservoir switch or its connection.

If the on/off switch is good, and the reservoir switch is good, then you may have a problem with a relay inside the Gicar controller, as in this thread: Giotto not maintaining boiler pressure .
Pat
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Randy G.

#4: Post by Randy G. »

homeburrero wrote:Although it goes without saying, I'll say it anyway --
Working a machine while plugged in is potentially very dangerous. You have to know what you're doing, be very aware that two hands with access to a 240V potential can kill you. .
It is, indeed, a good thing to state that. Can't be said enough. Having been tossed half way across a bedroom by 120, I know. If you do not know basic safety procedures for working with AC, don't do it. Take the thing in to be serviced. Even just replacing the control box as a guess is better than being dead...
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gahobbsau (original poster)

#5: Post by gahobbsau (original poster) »

Thanks for the responses Randy G and homeburrero. I have also read your contributions at ECM Giotto diagnosis assistance needed - no green light.

240v safety: Regarding the 240v I fully agree and keep powered testing to the minimum. Safeguard is the Earth Leakage Circuit Breaker (ELCB), though I don't want to be calling on that.

Controller diagram: Adding to the information provided in my first Post, please find below a pic of the layout diagram for the Controller board in my machine. This is the diagram on the outside of the case.


Relay failure: Regarding relay failure, I have not located that yet on the 7 pages of the thread at Giotto not maintaining boiler pressure. Perhaps you could point me to the page or post reference.
I have elsewhere read about failure of the relay as a common cause of no-go machine and also read there a description of the option of a little handy soldering to replace the relay (a low cost item) on the board rather than purchasing the whole board kit (a big cost item).
At this stage, I am trying to identify and eliminate other likely failure points before I jump into that solution. I figure that I also reap the benefit along the way of better understanding my machine and its workings.

The relay is located inside the controller box on the 240v side board. It is the black box in this close up pic.


Referring to my wiring diagram in my original post above, is at the end of the Active Brown cable where it enters the box. Can anyone tell me, from the diagrams, which wire would be on each of the four poles of this DSPT relay? That is which cables are doing the switching and which are being activated. I get the sense that the activated circuit is the Black cable that leads to the ThermoStat via the Thermo Cut-off Switch.

======================
Responding to the specific diagnostic questions asked by Randy G and homeburrero, I can report as follows.

Randy G:
Are you getting voltage across the Hot and neutral output terminals of the power switch? YES
Are you reading the same between the Brown wire at the controller box? YES
Check the connection for water level sensor at the reservoir: I earthed a cable with inline lamp from the white cable that attaches to the reservoir/receptacle. Got no lamp and no machine action.
Green light on front remains out.
I also used my grounded lamp cable to probe the various wires on the black connector to the low voltage board in the Controller - with the machine powered - but the lamp stayed unlit. This seems to indicate nothing happening on the low voltage board side and maybe indicate relay failure.

homeburrero:
Ground wires look to be connected OK and there appears to be no reason to suspect them.
For the water switch, rather than unscrew it, I ran a parallel cable with alligator clips. No action.
I also performed some continuity checks (with power off) as you recommended in the earlier thread that I have linked at the top. I found continuity with power switch on between the Neutral blue side with all points on the black through the Thermo cut-off, Presssurestat and Heating element.
I have probed various combinations of the low voltage wires on the black connector but do not appear to get any continuity.
Pic of connectors to my Controller follows:


===================
In summary, I get both no heating and no pump action.
I think that perhaps I had better start ordering that Relay.
Any alternative guidance based on the information that I have provided above?

Thanks again for your interest and assistance in my discovery and exploration of my problem and its solution.

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erics
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#6: Post by erics »

And don't forget about the transformer shown in your pic. That transforms the ~230 VAC into ~9 VAC which then gets rectified to ~9 VDC which powers the relay(s). There has been an equal number of transformer failures if I can sorta remember correctly.

You should try to post better pics of the board(s) front and back.
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Eric S.
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E-mail: erics at rcn dot com

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homeburrero
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#7: Post by homeburrero »

erics wrote:And don't forget about the transformer
Yes, especially in a young/newer machine. Older machines that have done a ton of switching would be more likely to have relay problems.
gahobbsau wrote:Regarding relay failure, I have not located that yet on the 7 pages of the thread at Giotto not maintaining boiler pressure. Perhaps you could point me to the page or post reference.
Relay discussion on Page 2, and on Page 4 lots more relay discussion, with one poster (jimmy) fixing his machine by replacing a relay. Here's another Giotto thread that resolved to a relay problem Boiler heating element is unreliable - Rocket Giotto 2007. I don't think any of these have controllers identical to yours though.

gahobbsau wrote:option of a little handy soldering to replace the relay (a low cost item) on the board rather than purchasing the whole board kit (a big cost item).
Another option, one that I've used twice now, is to ship the thing to Boyt Enterprises (HB member jpboyt) for repair and testing. Probably want to contact him first to make sure he can do your controller.

The various Giotto's do come with a wide variety of controllers. Yours has a different in pin layout than the one that matches the wiring diagram you posted, but seems to be functionally equivalent. (FYI, Here's a pic of one with a pin layout that matches that Giotto PP V2 wiring diagram:

)
gahobbsau wrote:I also used my grounded lamp cable to probe the various wires on the black connector to the low voltage board in the Controller - with the machine powered - but the lamp stayed unlit. This seems to indicate nothing happening on the low voltage board side and maybe indicate relay failure.
I don't think that's a good test.* In the case of the autofill and the reservoir switch/sensor wires, I'm pretty sure no current is supposed to flow. They are capacitive sense circuits, so they would not light your bulb. If you put a DC voltmeter on them I think you should see voltage. When the controller is working, you should be able to ground and unground the reservoir sensor wire and hear the main relay click. And unground and reground the boiler probe (autofill) wire and note that the pump and solenoid go on and off after a slight delay. (ungrounding the reservoir turns everything off, ungrounding the boiler probe turns the pump and solenoid on.)
gahobbsau wrote:Can anyone tell me, from the diagrams, which wire would be on each of the four poles of this DSPT relay?
Not me. But it would be logical that when the relay opens you would have no voltage on the black wire to the thermoswich/pStat/Element wire, and no voltage to the white pump or solenoid wires. I think it also cuts voltage to the lamp on yours.

I think you should have other relays in there. You need a high amp relay that shuts it all down, which I think is the one you pictured, and other separate lower amperage relays that fire up the pump and solenoid.

*edit addition: Not sure I understood your test here. When I posted this I was thinking you were looking for current between the ground and the sensor wires on the low voltage side, but none of those is black.
Pat
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gahobbsau (original poster)

#8: Post by gahobbsau (original poster) »

erics wrote:You should try to post better pics of the board(s) front and back.
Pics of the board top and bottom follow.




homeburrero wrote:*edit addition: Not sure I understood your test here. When I posted this I was thinking you were looking for current between the ground and the sensor wires on the low voltage side, but none of those is black.
"Black" is referring to the connector not the wire. On my board, the connector for the low voltage side wires is black, connector for the high voltage wires is green.

Will return later to working through other items in your helpful post homeburrero.

BTW, is there anywhere on the web a page or document about "How a home E61 Espresso machine works" or similar?

Thanks again for your interest.

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erics
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#9: Post by erics »

Thanks for the nice pics of the boards.

Obviously, I am focusing on that transformer. Do you see any part number on it that you can post?

See this: http://www.myrra.com/home . It APPEARS as though that transformer has one input and two outputs. The input would obviously be your line voltage and the two outputs would be (grain of salt) ~18 VAC and 5 VAC.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

gahobbsau (original poster)

#10: Post by gahobbsau (original poster) »

erics wrote:Obviously, I am focusing on that transformer. Do you see any part number on it that you can post?
Thanks erics. Transformer is a MYRRA 44122 for which see pic of details on the side following.
I have also located and downloaded a data sheet for this tranny but the relevant details can be read on the side in the pic.



Thanks for the interest and assistance.