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Date: 24 Feb 2007 22:36:51
From: Farid Nacer
Subject: Dead Gaggia MDF
It seems like things are conspiring to keep me from having coffee
these days. I opened up my Gaggia MDF grinder recently to clean it up.
When I pulled the motor out, I found a power wire just dangling.
Apparently, it was just soldered to the circuit board. I can solder it
back but I can't tell with certainty where it goes. If anyone happens
to have a photo of the circuit board showing the wires, I'd greatly
appreciate a copy. Thanks.

Farid





 
Date: 26 Feb 2007 04:24:31
From: daveb
Subject: Re: Dead Gaggia MDF



Moral to the story > Don't take apart things that are working. AKA:
If it ain't broke, don't fix it.

:-(

Dave



 
Date: 26 Feb 2007 03:02:49
From: Felix
Subject: Re: Dead Gaggia MDF
Farid Nacer (@gmail.com) writes:
> I opened up my Gaggia MDF grinder recently
> to clean it up. When I pulled the motor out, [...]

Overzealous grinder maintenance was recently discussed here.

> I found a power wire just dangling. Apparently,
> it was just soldered to the circuit board.

This construction technique suggests that motor removal shouldn't be
done that often. (On the other hand, I did something similar when I
cleaned my apartment's intercom. I was surprised it worked after I
reassembled it.)

> I can solder it back but I can't tell with certainty
> where it goes.

I'm not very familiar with the modern MDF, but I know that the older
ones don't have any logic inside: just a motor, a start capacitor, and
a switch. So, I'm guessing that the board doesn't have much on it
except for a bank of capacitors. If that's the case, it shouldn't be
that difficult to determine how to complete the circuit.

> If anyone happens to have a photo of the circuit
> board showing the wires, [...]

Alternatively, you could post a photo of yours at a.b.c, and someone
like Owen could figure it out for you, maybe even teach you how to
encase the board with potting compound :-) Calling the importer might
also work ...

My own Gaggia saga is finally nearing its end. For a while, I thought
one of mine was turning backwards, because it would "grind" without
spewing coffee into the doser. I also had a speculative theory about
removing the detent pins that depended on the rotational direction.

Earlier this month, I discovered that my theory was wrong. Pin and
spring removal depends solely on replacing their friction with PTFE
tape wrapped around the burr carrier. Four plies of cheap tape works
for me; I realize this is an imprecise specification.

Offline, Jim Schulman suggested that the grinder works just as well if
you use two settings per dose, i.e. turn the carrier while grinding.
That may be true, but the PTFE modification is simple to perform, and
more convenient in the end.

The other discovery was actually two. I thought I had two more MDF's
in storage, but discovered that there was only one, and that it's from
the same era as the one that doesn't work. They both have the center
post, and turn in the same direction. So, I don't have an electrical
problem, and look forward to not being surrounded by MDF parts
someday.


Felix