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Mark Kent
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Default Circuit diagram for Tek 2225 scope PSU

Martin Whybrow espoused:

"Mark Kent" wrote in message
Hi experts,

Would anyone have access to a circuit diagram for a Tektronix 2225 50MHz
analogue scope?

The PSU went bang today; it appears to be both of two 2200pF caps,
one from live to earth and t'other from neutral to earth.

I'm assuming that they're both there merely for HF suppression from the
scope onto the mains supply.

The remainder of the devices seems to be fine, indeed, the trace was
still up after the 'bang', but I switched off PDQ anyway.

If anyone's got any hints or info for this scope, or suggestions regarding
the best type of capacitors for this purpose, I'd very much appreciate it.

You need to make sure that the replacement parts are class Y rated types. It
would be a good idea to find out why they went bang in the first place,
especially as both blew simultaneously.

It makes me deeply suspicious that they both failed, not only that,
but rather spectacularly too. The scope had been in storage for
some time, so it's possible it'd got damp, though why that should
result in exploding caps is beyond me atm.

I think I'll have to replace the caps, with suitable types as you
suggest, and run it up again to see what happens.


| Mark Kent -- mark at ellandroad dot demon dot co dot uk |
But you shall not escape my iambics.
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