Quickmill Andreja Premium: Water level probe and boiler refill problem--It's the Giemme control box!

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stevescapin
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#1: Post by stevescapin »

I hope someone can explain the weird behavior I noticed with my andreja. When I disconnect the water level probe, the refill pump does not start (at least, not always and this is especially true when the machine is hot) I make sure when I disconnect the wire that it does not touch any other part of the machine.

What could be responsible for such a strange behavior? Could it be a sign that the control box is broken? I was under the impression that whenever the probe is not grounded (i.e., not in contact with water in the boiler) the pump starts automatically.


Steve

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erics
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#2: Post by erics »

Not an easy problem to solve, Steve. Below is a pic of an undressed Gicar for the Anita - Andreja should be VERY similar, if not identical.



The transformer takes 120 VAC and has taps for 18 VAC and, I believe, 5 VAC. The 18 VAC is rectified to DC to operate the double pole single throw (DPST) relay coil and the 5 VAC is used in the autofill sensing circuitry. One of the poles of the relay supplies power to the fill solenoid and the other powers the pump - obviously simultaneously during autofill operations.

The Gicar controller in the Quickmill line has been very reliable - not that it can't fail - but that this would be the first instance I can remember on a QM machine - corrections strongly invited. With that in mind, I would first look at some other "things" because the sound we all hear when autofill takes place is that of the pump. Are the electrical connections to the pump secure, is the little "Klixon" thermal diode on the pump secure in its pocket?
Skål,

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

stevescapin (original poster)
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#3: Post by stevescapin (original poster) »

Eric,

Thanks for replying to my post about the weird behaviour of my Andreja. I have narrowed down the problem to the Giemme control box and heat seems to be the issue. Boiler refill works for the first 30 minutes after I turn on the machine and then it stops. When I take the control box out of the its case and use a fan to force some air on the components, boiler refill works perfectly even after leaving the machine on for 8 hours. The probable culprit is the transformer, which starts acting up when it gets too hot.

My question: can the transformer be replaced? Would you know the replacement part and where I could find it? I am not terribly handy with electronics, but there is a repair shop that could do the work if I bring in the parts.

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erics
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#4: Post by erics »

Boiler refill works for the first 30 minutes after I turn on the machine and then it stops.
I'm thinking I would want to be 110% positive of this. Give me a call, late, when your espresso day is over and we can discuss - 301-587-5033. If, in absolute fact, the transformer is the culprit, it MAY be sorta cost effective to replace the entire control box.

I'm thinking - transformer total cost + outside labor + your labor is not that much less than control box cost + your labor.
Skål,

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

stevescapin (original poster)
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#5: Post by stevescapin (original poster) »

You are probably right--I should just buy a new control box. Given my ignorance of electronics, I thought that the transformer could be really cheap. From what I understand now, this might not be the case. I also value the peace of mind provided by the installation of a new unit.

One last question: are gicar and giemme interchangeable? Are gicar more reliable?

Thank you again for your help!

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erics
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#6: Post by erics »

I thought that the transformer could be really cheap.
I'm sure it is - $15 + shipping - this is just a guess. Then there's the "problem" of getting a workable match, paying someone to unsolder/solder in same, and cross your fingers. I can foresee all kinds of roadblocks/accidents waiting to happen.

Don't get me wrong - this laborious process has been done before - particularly with Giotto control boards where the replacement cost was about double yours (supply/demand/complexity/availability). Look up forum member "jpboyt" - I'm fairly certain he has the in-house capability to repair your controller. The alternative is to give Chris Coffee a call tomorrow and the board will be on its way.

Gicar and Giemme are most often used interchangeably - perhaps incorrect but I don't know.
Skål,

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

ira
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#7: Post by ira »

I have accidently ended up in the espresso machine repair business. A local repair shop found me on the Brewtus list and occasionally asks me to look at small machines that have electrical problems. Last week I repaired a Gicar box on an ECM Giotto where the electrolytic power supply capacitor had lost 1/2 of it's capacity. Replacing the diode bridge and all the 105C electrolytic caps with higher temperature 125C and 150C parts fixed it. So, I'd say f you're trying to fix a Gicar box and you have good soldering skills but no scope and there is some output from the transformer, replacing the capacitors and maybe the diode bridge is a good place to start. The symptoms on this one were a clicking relay when you turned it on. If the heater was not commanded, no water in the tank or boiler, than the machine acted correctly, but as soon as the boiler was full and there was water in the water tank, the heater relay just started clicking on and off.

Ira

jpboyt
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#8: Post by jpboyt »

First question to answer, as far as the transformer replacement is concerned is whether or not it has a dual voltage secondary. If you have two secondary voltages listed you ain't never gonna find a replacement. These were manufacturer specified transformers. May be available if you want to factory order a few hundred gross. This is one of the several electrical schemes used for water level detection and refill. It runs one of the secondary ac voltages through the boiler to complete the circuit before rectification. If you notice that you have two of the the four legged bridge diodes (black, round with a flat, and + sign and two squiqqles), you have two different ac voltages being rectified. It is the equilization of the two voltages that turn on or shut off a transistor that runs the relay. I have found it more cost effective to replace autofill boxes with the dual secondary voltages than attempt any repair other than caps and relays. Sometimes I fix them just because they start to pile up and I can do a bit of cannabilization.
jpboyt

ira
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#9: Post by ira »

Thanks for that. I've only repaired about 4 machines so far, all successfully, but I'm just starting to learn and the double coil problem is a good thing to remember.

Ira

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allon
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#10: Post by allon »

I am moderately experienced with the art of electronics repair, and would be happy to help any members in the Washington DC Metro Area with soldering, if they need help with their machine.

I know that doesnt help the OP, but I thought I would offer in case anyone else needs help. No guaranteed results, and I might try to teach you to solder in the process.
LMWDP #331

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