Oscar Professional No Power

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
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Joined: November 24th, 2010

Postby SudburyTony » Nov 24, 2010, 4:27 pm

I have a Nuova Simonelli Oscar Professional Espresso machine that no longer turns on. I was using it one day and heard a pop. I turned it off and now it will no longer turn on. No lights, no heating, just seems dead. I've opened it up and looked inside and everything appears OK (wires all connected, nothing looks burned or anything out of the ordinary). Unit is probably 10 years old and has been fairly lightly used over the years.

FYI - I have checked power at outlets and tried several just to be sure it isn't something that simple.

Thanks to anyone that can help.

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Postby caeffe » Nov 24, 2010, 6:32 pm

try the info on this thread:

Nuova simonelli oscar doesn't heat up

hopefully it is just the high temp limit switch that has been tripped. otherwise it could be the "brain" box.
LMWDP #162

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Postby SudburyTony » Nov 25, 2010, 3:07 pm

The Oscar doesn't seem to have a resettable high temp limit switch. Since the "brain box" is around $200 I am hoping it is something else. Anyone have any other ideas that I can check (and any ideas on why the circuit boards would suddenly die?).

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Postby erics » Nov 25, 2010, 3:56 pm

As per the electrical diagram available in the Oscar manual here - http://www.nuovadistribution.com/oscar.html , you have two wires leading to the water reservoir. One is most definitely a ground, the other leads to the control box. When the control box senses no continuity, it probably shuts the machine down.

Turn the machine off and unplug it. Now temporarily connect the two wires leading to the reservoir together and see if the machine will power up.

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

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Postby Carneiro » Nov 26, 2010, 2:19 pm

As far as I know, the water sensor should stop the machine but the power light should be on (I think there is a "water level" light for this status).

There is a resettable safety thermostat indeed, at the side of the boiler. If you look at the page 5 of the parts breakdown, the part number is 09500004.

If the electronic box is damage, I know a Italy store that has it for EUR 73 + shipping.

One thing I've notice about the Oscar I'm restoring is that the heat element seems to be rated at 1200W for 110 or 115V. I think I measured 9.8 Ohms. So I'm having around 1600W (power line here is 127V) and a very hot power cord during warm up (almost 13A). I'll double check the heater wiring inside the machine and change the power cable, but the relay inside the electronic box is rated 16A - it should work fine.


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Postby SudburyTony » Nov 28, 2010, 1:24 pm

Thanks. I see the 09500004 part on the side of the bioler and it has a little "button" on it, but it doesn't seem to be a button you can press. I can spin it, but not push it.

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