On Sun, 22 Aug 2021 10:03:10 +1000, Sylvia Else <sylvia@email.invalid>
wrote:

>On 21-Aug-21 2:06 pm, Sylvia Else wrote:
>> My 40 year old scope seems to have failed again the same way it did a
>> while back - one of the X-axis drive transistors has failed - the same
>> one as last time. Could just be chance again, but one has to wonder.
>
>Further examination shows that it's actually the corresponding
>transistor in the other half of the X-drive circuit. Which makes a
>warped kind of sense, so I will try replacing it.
>
>Sylvia.

It takes a scope to fix a scope.

--

Father Brown's figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.

On 22-Aug-21 2:07 pm, jlarkin@highlandsniptechnology.com wrote:
> It takes a scope to fix a scope.

Sometimes, perhaps. But in this case, the symptom is that half the
x-axis doesn't get used, with a bright dot in the middle instead. And I
already knew that failure of a transistor in the final x-axis amplifier
could cause this.

Sylvia.

On Sun, 22 Aug 2021 14:14:37 +1000, Sylvia Else <sylvia@email.invalid>
wrote:

>On 22-Aug-21 2:07 pm, jlarkin@highlandsniptechnology.com wrote:
>> It takes a scope to fix a scope.
>
>Sometimes, perhaps. But in this case, the symptom is that half the
>x-axis doesn't get used, with a bright dot in the middle instead. And I
>already knew that failure of a transistor in the final x-axis amplifier
>could cause this.
>
>Sylvia.

I was right. It fixed itself.

--

Father Brown's figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.