[BrendaAnnD]

.. that would be willing to tackle a wonky Tek 500MHz 4 channel digital scope? I'm more than willing to pay for repairs (but not necessarily Tek rates!).

I'll provide the model  number a bit later.

TIA

[morzh]

Brenda,


I would but right now I am in a process of buying a house and will be consequently moving etc, so right now the timing kinda sucks for me to do anything of the sort.

However the thing being repairable would also depend on what kind of a digi-scope it is, computer-based (motherboard, Windows and all), microprocessor / microchips usage, type of a PCB inside, chips' technology (BGA etc).......depending on it all the repair might be outside of possibility if not equipped to do such things. Gosh knows it might require LSI chip rework station.
Plus uProcessors have code in them, and if it croaked, well, good luck with it.

This is why old analog with proper bandwidth is more repairable.

[Chuck Schwark]

And not to mention, the notorious silver-plated ceramic terminal strips.

[Image: http://www.partsconnexion.com/media/prod...-70669.JPG]

:-)

Chuck

[BrendaAnnD]

OK... the model of the scope is TDS540B. I REALLY want this thing to be up to par, so I'm willing to pay and willing to wait.

Also, I have an HP8656B signal generator (100KHz to 999MHz) that has had something go out in the output section. Some frequencies still have a decent output, but a lot of them are WAY down. It does still work at all frequencies, but the output curve looks something like a rollercoaster. If anyone wants to try their hand at repairing that, it's worth some good money to me as well.

[morzh]

Oy vey....


Brenda,

What's wrong with the idea of yourself taking a stab at it first?

[BrendaAnnD]

This stuff honestly scares me. I've got virtually no experience with digital, and the last time I opened a scope I was just overwhelmed. I know my limits.

[morzh]

Brenda,

Digital is simpler than analog.
Way, way simpler.

On the engineering world digital folks envy us, people who know analog.
Digital folks are dime a dozen.
Many of them have the faintest idea about how currents behave.
Digital, if not High Speed, is extremely simple.


The poblem is not digital, but the fact that these might contain a micropocesor with code, or an FPGA, and if this goes, other than manufacturer no one really can help you. Code is, well, code.

[Mondial]

As far as repairing the HP 8656B, the difficulty will be getting parts since it is no longer supported by Agilent or its new successor. These generators use custom hybrid microcircuits in the output stage, so without the replacement parts repair is next to impossible. I believe this generator uses a PIN diode switched attenuator at the output, which may be where the problem is.

Probably the best solution would be to find a inexpensive parts 8656B on ebay, and use it to interchange modules to localize the problem.