VCR AIWA HV-MX1U, a bit strange...

[Peter Lehmann]

Hi there,
this VCR will not operate properly.
When switched on, the headdrum starts to rotate. When I try to load a
tape, the cassette is ejected immediately.
In the display, the label "DEW" ist lit. (rotating drum for faster drying?)
But I can't find any dew-sensor in the drive-mechanism.
The on/off button works, every other button is ignored.

Is there any idea?

73
Peter

 

[Jerry G.]

I would not know physicaly where the dew sensor is in your machine, but
it is possible that it is defective. It is also possible that the
electronics that it feeds may be defective.

Jerry G.
======

 

[b]

Hi there,
this VCR will not operate properly.
When switched on, the headdrum starts to rotate. When I try to load a

tape, the cassette is ejected immediately.
In the display, the label "DEW" ist lit. (rotating drum for faster drying?)
But I can't find any dew-sensor in the drive-mechanism.
The on/off button works, every other button is ignored.

if this unit is about 4-5 years old or more, and strange things happen,
just replace the electrolytic caps in the power supply section. Some of
these units are now starting to drop dead.
-Ben

 

[worldcitizen]

The dew sensor is usually a small flat square about a quarter inch
square or smaller and about a sixteen of an inch thick with two pins or
wires coming out of one edge that is sometimes mounted near the capstan
or in that general area that monitors the level of humidity present
inside the vcr. Maybe take the cover off and blow dry the carrage area
for a few minutes and see if the dew light goes out. If it does then
you are good to go, if it doesn't then you may have a problem in the
circuit that monitors that sensor.

 

[Peter Lehmann]

Hi there,
Thanks for reply.
I think, this VCR has definetly no DEW-sensor. In the upper right corner
of the drive-mechanism is a small PCB with two connectors. One is for
the loading-motor, the second is marked DE and -empty- :-(
Since I am working on VCRs for more than ten years, I know how a
DEW-Sensor looks like and works, but naturally you know nothing about my
skills.

So I will check the PSU and wait for more ideas.
Normally I would give up such a VCR (Longplay, but no HiFi-Sound), but
it is a multinorm (PAL, NTSC, SECAM), so I should try to save it.

73
Peter

 

[b]

Hi there,
Thanks for reply.
I think, this VCR has definetly no DEW-sensor. In the upper right corner
of the drive-mechanism is a small PCB with two connectors. One is for

the loading-motor, the second is marked DE and -empty- :-(
Since I am working on VCRs for more than ten years, I know how a
DEW-Sensor looks like and works, but naturally you know nothing about my
skills.

So I will check the PSU and wait for more ideas.
Normally I would give up such a VCR (Longplay, but no HiFi-Sound), but
it is a multinorm (PAL, NTSC, SECAM), so I should try to save it.
73
Peter

Peter,
Just thought of another thing you could look at.
Yesterday I repaired a SABA vcr with similar symptoms: buttons ignored,
power flashing on-off, unusual mode cycling, etc.
Turned out that the front rewind switch was being pressed in
permanently by part of the plastic front panel button, which had
deformed. I discovered that when the front panel was removed the unit
worked fine with but would go crazy when it was replaced.

regards, Ben

 

[Peter Lehmann]

Hi Ben,
the Came into the workshop this morning and plugged the VCR into
mains.
VCR came up immediately and worked fine.
I think, I should not understand this yet. Life is too short ;-)
At this time I assume static charge at the DEW input of the
control-processor. I have no schematic to verify this.

In my last post I had an error. The unused connector is marked 'DW'.
Seems to be for an DEW sensor.

Let's hope the VCR will work the next days so I can return it to the
customer.

73
Peter

ps.: In the past I also had stuck buttons. This failure also occured
when front panel removed.