[sdiy] (Slightly OT) - Help to repair Hameg Scope, Please

[Chris Manders]

Please ignore my last plea - I acually found out what
the problem was!

The scope looks excellent build quality, but examining
the circuit boards inside I noticed that the leads on
the final transistors had not been cut off - They were
just left long. Very bizarrely, two of the legs of one
of the final transistor on the X Amp board had been
pushed (shorted) together.

I squeezed them apart, and PRESTO HEY! The X axis in
now fine.

Hmmm . . . . No idea what the previous owner had done
to cause that . . . 

Thanks
Chris


--- Chris Manders <wight446 at yahoo.com> wrote:

> Hi folks
> 
> I managed to obatin (relatively cheaply) a nice
> Hameg
> scope, which has a fault. This is model HM203-5.
> 
> Before embarking on a repair, I thought I would
> throw
> it open to you knowledgeable guys out there for any
> comments or advice.
> 
> It appears that the scope has a problem with the X
> axis. See the following photos:
> 
> http://www.geocities.com/wight446/hameg1.jpg
> 
> This shows the scope with the Y timebase off, and
> all
> the controls at centre. The Dot should be in the
> centre of the display. It isn't.
> 
> http://www.geocities.com/wight446/hameg2.jpg
> 
> Shown now with the Y Timebase running - The scan
> should go across the screen.
> 
> No matter what controls I attempt to use (even the
> obvious X position control) I cannot get the dot to
> appear anywhere other than to the left of the
> screen.
> (With the X Position control turned fully to the
> right, the dot is one segment to the left of
> centre).
> 
> I managed to get a schematic diagram, and my initial
> thoughts are that maybe one side of the 'push pull'
> X
> amplifier circuitry is down.
> 
> I guess I would best be getting a scope in order to
> repair THIS scope.
> 
> Any thoughts, hints and advice are most welcome.
> 
> Thanks
> Chris
> 
> 
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam
> protection around 
> http://mail.yahoo.com 
> 


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com