2007-05-05
UPO MAXI 615 washing machine This washing machine started to
behave strange just about a year after we bought it. It took
much longer to complete a program than it should (there is a
display on the front panel, indicating remaining time), a couple
of times the drive belt between the motor and the drum jumped of
and sometimes the motor just revved up for a short time (which
probably caused the drive belt to jump off).
Once when I stood and watched it during a program, the motor
revved up very shortly and then the time left display switched
to another time and the program reset itself to an earlier
program sequence.
The
machine had a small controller circuit board with a processor,
some relays and what appeared to be a motor controller and a bus
connection to another circuit board for the indicators and
controls on the front panel. After examining the controller
circuit board I noticed that there where some very poor quality
solder joints and it seemed that there, at some time before, had
been done some repair work on this circuit board. It was indeed
the bad solder joints that caused the problem, probably by
causing intermittent disconnections to the processor which
jumped out of it's program and sometimes reset itself. After
resoldering the circuit board the machine worked fine. Perhaps
it was my imagination, but I thought that the machine from now
on, worked better than ever before.
This is a machine with a high rev centrifuge which vibrates
pretty much when going at highest speed. This, in combination
with the bad soldering joints, caused the problem.
2007-05-05
UPO MAXI 615 washing machine