On 22/01/2010 04:14, Andrew Erickson wrote:
In ,
wrote:

Usenet Inscribed thus:

Baron wrote:
Usenet Inscribed thus:
I've scanned and uploaded the diagram he
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. :-)

Is this indeed a rotary switch model, rather than one with all
electronic controls and a fancy touch panel? If it's the former, it
sounds possible to me that the rotary switch is at fault--either the
little timer motor for it isn't turning it (because of motor or gear
train failure), or some of the contacts are not operating properly. The
first failure mode could be tested by manually turning the switch by
small bits and seeing if the dishwasher goes through the proper stages
of washing that it's currently missing. The latter problem would
require a timing diagram of the switch to diagnose easily; there's a
chance there may be one pasted into the machine somewhere, or associated
with the schematic.

It does seem rather odd to me that, if it's a rotary switch model, the
various wires to the switch aren't shown on the schematic. On the other
hand, it is a slightly strange schematic to begin with, so I guess it
wouldn't be a complete shock.


Couple of possibilities not so far mentioned I think. On one or two
models of d/w an open circuit heating element will prevent the main pump
motor from running. Also, failures of the wiring loom where it flexes as
it passes between the door and main body of the machine are common enough.

On most machines, clicking the timer switch on by hand should step the
machine through it`s program. usually starting with:- drain, fill, fill
+ main motor, drain, etc.

Ron(UK)