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From: Usenet on 20 Jan 2010 21:57
Baron wrote:
> Usenet Inscribed thus:
>>>>I've scanned and uploaded the diagram here:
>>>> http://i49.tinypic.com/28r1thw.jpg
>>> Find & check switch 6.
> If that switch is OC the main motor will not run. The other side is via
> the timer. 6th contact from left marked (1)
>
> There is also a cutout marked 7/ that should be checked. It may be a
> manual reset.

Just to get things straight: what kind of switch is this switch '6?
It's normally closed, yes? Do you think -- by it's position in the
diagram -- it's the flood protection switch?

Where would cutout 7/ be, physically? Is it on the pump itself?

Switch '6 also controls the things immediately to the right of the
main circulation pump, labelled :9, '5, and 59. These look like
solenoid-type thingies, the ones with "triangle propellers" look maybe
like valves. Are they solenoid type things? The circle labelled '30
I'm pretty sure is the drain pump (in Europe apparently it's usual to
have two separate pumps). This pump still works.

What is your guess for the thing labelled )0 off contact 13 from
the left? It must be acting as some kind of sensor, I'm thinking, by
it's position on the right of the diagram.

I've checked for continuity and there's no breaks in the wires that
I can find. However, during operation of a dishwasher cycle, no voltage
is ever given (by the brand new replacement controller!) to the main
circulation pump, as measured with a multi-meter. Therefore -- it looks
to me -- like the controller is expecting a signal to proceed, which it
never receives.

What is the symbol marked 17&, over towards the right? It looks a
bit like a Christmas cracker, so I'm hoping it's some fusey cut-out
thing. I would dearly love to know its meaning.

Having had a good look at the innards of my dishwasher, I'm not
intimidated by it anymore. They're really very straightforward things.
I can feel it's not far from working. It's really frustrating right
now, but I now feel I *can* get it working again.

... and of course, if it stops me having to wash up by hand every
day, that would be WONDERFUL!!!

Regards,

Sandy
From: Usenet on 20 Jan 2010 22:00
William R. Walsh wrote:

> I think you will find that you have a relay in your dishwasher with
> burnt contacts. This will prevent the pump from ever getting power. If
> you have an electronic set of controls, there ought to be some relays
> somewhere.
>
> Since you mentioned that replacing the controller board did not
> resolve the problem, I would say that there is a separate power
> control and distribution unit elsewhere in the unit. You should locate
> this part and see what's inside or on it.
>
> It's less likely but possible that there are fuses protecting each
> major circuit in the unit. One of these may have blown. Nuisance fuse
> blowing is possible but unlikely. If there is a fuse and it blew,
> there is likely a fault in the circuit.
>
> If you do end up finding that a burnt relay is the problem, you can
> sometimes repair it by carefully levering the cover off the relay and
> cleaning the burned contacts. Unfortunately, opening relays can
> involve violence, and sometimes you just can't do it without
> destroying the relay itself.
>
> The wiring in your dishwasher should be pretty straightforward (but
> this will vary depending upon how many functions it has). It should be
> possible to trace out each wire and determine what it does.

I'm pretty sure my dishwasher has just the one PCB. I've just
spent the evening with the dishwasher on its side, checking for
continuity and tracing the wiring, and locating and inspecting water
tubes and devices. And of course, drinking cups of tea and eating
biscuits (cookies?). No wires broken, alas so the mystery is still at
large. I checked the dishwasher's operation again -- the controller
definitely never sends voltage to the main pump. But every 5 minutes or
so it fills a little bit more, I watched it do this for 40 minutes, and
then got fed up and had to press the button to make it drain and stop
the cycle.

By the way, I've uploaded the manufacturer's circuit diagram for my
dishwasher at: http://i49.tinypic.com/28r1thw.jpg

Also, here's a picture of the one and only PCB in my Beko "DE 2541
FX" slimline dishwasher, at: http://i49.tinypic.com/30bn60i.jpg

(...Are the black and blue blocks on the left, in lieu of the relays?)

But it is very interesting what you said about burnt relays...

...On the day the dishwasher went wonky, that morning we had just
had our electricity reconnected to the mains grid after a week of being
without electricity. (They were logging nearby in the forest.) When
our supply was reconnected, actually *three* things went wrong that day.

1) A long-life bulb stopped working.

2) My Bosch jigsaw stopped working.

3) The dishwasher worked in an odd way for several "clearing the
backlog" washes -- there were longer and longer pauses between the
filling/heating, and waiting for the swishing sound of dishes being
cleaned. On the last successful go, the swishing suddenly started an
hour after starting a run. (It startled me, in fact!)

After three things had independently gone wrong, I measured the
voltage of the mains (supplied from step-down transformer from overhead
wires that snakes across our forest). The normal domestic mains voltage
in England is 230-240 volts AC. That afternoon ours read 255 volts,
which slowly came down after a several days to 240, and then back down
to it's usual 235-ish.

While tinkering this evening with the dishwasher, I was thinking
that (apart from the possibility of blown fuses/relays) it had to be
EITHER a bad sensor -- an input to the timer/controller -- that is not
performing, OR that a process is not happening (because of a solenoid
etc.) that ultimately leads to an undesirable reading from a sensor.
That's to say "If no voltage ever gets sent to the motor by the brand
new replacement controller, then the fault is because the dishwasher
programme must be waiting for an OK signal from somewhere in the system
that never arrives."

This happens on the simple 15 minute "pre-wash" setting (no heating
of the water is involved, so that clears Mr. Thermostat from the list of
suspects).

Because of the unusual voltages on the day the dishwasher died, I
think it most very probably must be a high-voltage actuator (a solenoid
or a fuse) that's gone, and probably not a low-voltage sensor.

I would very much appreciate anything you have to say.

Regards,

Sandy
From: hr(bob) hofmann on 20 Jan 2010 23:07
On Jan 20, 9:00 pm, Usenet <use...(a)abel.co.uk> wrote:
> William R. Walsh wrote:
> > I think you will find that you have a relay in your dishwasher with
> > burnt contacts. This will prevent the pump from ever getting power. If
> > you have an electronic set of controls, there ought to be some relays
> > somewhere.
>
> > Since you mentioned that replacing the controller board did not
> > resolve the problem, I would say that there is a separate power
> > control and distribution unit elsewhere in the unit. You should locate
> > this part and see what's inside or on it.
>
> > It's less likely but possible that there are fuses protecting each
> > major circuit in the unit. One of these may have blown. Nuisance fuse
> > blowing is possible but unlikely. If there is a fuse and it blew,
> > there is likely a fault in the circuit.
>
> > If you do end up finding that a burnt relay is the problem, you can
> > sometimes repair it by carefully levering the cover off the relay and
> > cleaning the burned contacts. Unfortunately, opening relays can
> > involve violence, and sometimes you just can't do it without
> > destroying the relay itself.
>
> > The wiring in your dishwasher should be pretty straightforward (but
> > this will vary depending upon how many functions it has). It should be
> > possible to trace out each wire and determine what it does.
>
>      I'm pretty sure my dishwasher has just the one PCB.  I've just
> spent the evening with the dishwasher on its side, checking for
> continuity and tracing the wiring, and locating and inspecting water
> tubes and devices.  And of course, drinking cups of tea and eating
> biscuits (cookies?).  No wires broken, alas so the mystery is still at
> large.  I checked the dishwasher's operation again -- the controller
> definitely never sends voltage to the main pump.  But every 5 minutes or
> so it fills a little bit more, I watched it do this for 40 minutes, and
> then got fed up and had to press the button to make it drain and stop
> the cycle.
>
>      By the way, I've uploaded the manufacturer's circuit diagram for my
> dishwasher at:http://i49.tinypic.com/28r1thw.jpg
>
>      Also, here's a picture of the one and only PCB in my Beko "DE 2541
> FX" slimline dishwasher, at:http://i49.tinypic.com/30bn60i.jpg
>
>      (...Are the black and blue blocks on the left, in lieu of the relays?)
>
>      But it is very interesting what you said about burnt relays...
>
>      ...On the day the dishwasher went wonky, that morning we had just
> had our electricity reconnected to the mains grid after a week of being
> without electricity.  (They were logging nearby in the forest.)  When
> our supply was reconnected, actually *three* things went wrong that day.
>
> 1)  A long-life bulb stopped working.
>
> 2)  My Bosch jigsaw stopped working.
>
> 3)  The dishwasher worked in an odd way for several "clearing the
> backlog" washes -- there were longer and longer pauses between the
> filling/heating, and waiting for the swishing sound of dishes being
> cleaned.  On the last successful go, the swishing suddenly started an
> hour after starting a run.  (It startled me, in fact!)
>
>      After three things had independently gone wrong, I measured the
> voltage of the mains (supplied from step-down transformer from overhead
> wires that snakes across our forest).  The normal domestic mains voltage
> in England is 230-240 volts AC.  That afternoon ours read 255 volts,
> which slowly came down after a several days to 240, and then back down
> to it's usual 235-ish.
>
>      While tinkering this evening with the dishwasher, I was thinking
> that (apart from the possibility of blown fuses/relays) it had to be
> EITHER a bad sensor -- an input to the timer/controller -- that is not
> performing, OR that a process is not happening (because of a solenoid
> etc.) that ultimately leads to an undesirable reading from a sensor.
> That's to say "If no voltage ever gets sent to the motor by the brand
> new replacement controller, then the fault is because the dishwasher
> programme must be waiting for an OK signal from somewhere in the system
> that never arrives."
>
>      This happens on the simple 15 minute "pre-wash" setting (no heating
> of the water is involved, so that clears Mr. Thermostat from the list of
> suspects).
>
>      Because of the unusual voltages on the day the dishwasher died, I
> think it most very probably must be a high-voltage actuator (a solenoid
> or a fuse) that's gone, and probably not a low-voltage sensor.
>
>      I would very much appreciate anything you have to say.
>
> Regards,
>
> Sandy- Hide quoted text -
>
> - Show quoted text -

It could well be that the over-voltage has fried some of the
electronics. That's why I always (#times in 45 years) get a
dishwasher with a mechanical timer. NOt as many choices, but a LOT
less that can go wrong.
From: Baron on 21 Jan 2010 15:46
Usenet Inscribed thus:

> Baron wrote:
>> Usenet Inscribed thus:
>>>>>I've scanned and uploaded the diagram here:
>>>>> http://i49.tinypic.com/28r1thw.jpg
>>>> Find & check switch 6.
>> If that switch is OC the main motor will not run. The other side is
>> via the timer. 6th contact from left marked (1)
>>
>> There is also a cutout marked 7/ that should be checked. It may be
>> a manual reset.
>
>Just to get things straight: what kind of switch is this switch '6?
>It's normally closed, yes? Do you think -- by it's position in the
> diagram -- it's the flood protection switch?

Yes its normally closed.

>Where would cutout 7/ be, physically? Is it on the pump itself?

Yes, probably, since its a thermal cutout. Looking at the diagram its
shown directly above the motor. Its normally closed.

>Switch '6 also controls the things immediately to the right of the
> main circulation pump, labelled :9, '5, and 59. These look like
> solenoid-type thingies, the ones with "triangle propellers" look maybe
> like valves. Are they solenoid type things?

9 & 59 are probably solenoid water valves. I'm not at all sure what 5
is.

> The circle labelled '30
> I'm pretty sure is the drain pump (in Europe apparently it's usual to
> have two separate pumps). This pump still works.

It that case it rules out switch 6. Since if 6 was open the pump
wouldn't run.

>What is your guess for the thing labelled )0 off contact 13 from
>the left? It must be acting as some kind of sensor, I'm thinking, by
>it's position on the right of the diagram.
>
>I've checked for continuity and there's no breaks in the wires that
>I can find. However, during operation of a dishwasher cycle, no
>voltage is ever given (by the brand new replacement controller!) to
>the main circulation pump, as measured with a multi-meter.
>Therefore -- it looks to me -- like the controller is expecting a
>signal to proceed, which it never receives.

One of those, possibly the one marked )0 is the timer drive motor.
366 could be the water level sensor.

>What is the symbol marked 17&, over towards the right? It looks a
>bit like a Christmas cracker, so I'm hoping it's some fusey cut-out
>thing. I would dearly love to know its meaning.

I think +)7 is the heater and 17& the soap dispenser.

>Having had a good look at the innards of my dishwasher, I'm not
>intimidated by it anymore. They're really very straightforward
>things.
>I can feel it's not far from working. It's really frustrating right
>now, but I now feel I *can* get it working again.
>
> ... and of course, if it stops me having to wash up by hand every
> day, that would be WONDERFUL!!!
>
> Regards,
>
> Sandy

The basic operation is that of a rotary switch driven by a motor. Once
a program has been chosen, the switch drive motor normally runs
continuously. A solenoid is often used to cause the switch drive motor
to step the rotary switch on to the next position depending upon some
criteria being met. This could be :- Fill level, Temperature, Time.
Usually the fill level has to be reached and water shut off before the
main pump motor is allowed to start.

Often the main pump motor and heater are not allowed to be both switched
on at the same time. Then when water temperature has been reached the
soap dispenser is activated. Then a timed wash cycle commences. Water
is drained. Refilled and rinse aid injected and a further wash cycle
starts.

This is followed by another heat cycle designed to create a high
temperature, and short wash before fully emptying. This is designed to
dry the contents and leave a polish.

All the above will vary depending upon the chosen program and is not any
more than a general description of operation. Being on the spot and
able to see what wire goes to which component is a great
advantage. :-)

--
Best Regards:
Baron.
From: Baron on 21 Jan 2010 15:53
Sandy,

I'm in the UK !

Drop me an Email.

--
Best Regards:
Baron.
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