Hi there,
I have bought a used "Wavetek 175" arbitrary waveform generator on eBay,
which was said to have a defective power switch -- now it turned out that
the power switch is perfectly fine, but there are other problems with it:
- When turning the device on, starts humming silently, showing that there is
power applied to the power supply. Thus, I find the switch to be okay.
This low humming is the same for "bad" and "good" behaviour.
- In about 4/5 of all power-on attempts, the display lights up random data
shortly, then turns dark again.
The service manual says that this is caused either by the "+5V logic
supply in overvoltage protection mode" or the "+15V supply in current
overload mode".
- After more switching on and off, the device finally turns on, and works
normally from then on -- until being turned off.
I live in Germany with nominal 230V mains voltage, so I jumpered the device
to the 240V setting, specified fr 216-252VAC. When it arrived, it was set to
the 220V jumper position, specified for 198-231V -- probably because many
years ago, the mains voltage standard here was changed from 220 to 230V, and
this device is older than that change.
As the power switch was described faulty by the former owner, I suppose the
problem observed has been present with the former setting, too. I only
tested that 220V setting once, and the device did show the same symptoms as
with the 240V setting.
Now my question, with the hope for an answer of other users of such aged
equipment: Is there any prime suspect for this type of failure? Something
in the Wavetek 175 that uses to fail after some years?
I did send mail to "Willtek", a company that once bought Wavetek, but they
"sold the product group to Fluke" and do not have any more information on
the thing. Fluke, on the other hand, did not reply to my inquiry.
So, any help would be very appreciated.
Thankyou, and best regards,
Thiemo
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