Re: TDS 380 won't trigger

Gary Appel

Thanks Siggi,

I wrote that e-mail just before I turned off the computer last night. I should have added information about error messages.

On power-up I get the following messages:

Pass -- Powerup Checks
Fail++Cal Initialization

Diagnostics gives me the following messages:

Acquisition: Fail
Calibration: Fail
CPU: Pass
Display: Pass
Front Panel: Pass

The Error Log has the following failures, consistently:


I don't see anything referring to a checksum or NVRAM failure.

Looking at the acquisition board, the only electrolytic caps I see appear to be at the analog inputs.

This is the first time I've opened this 'scope up, and I'm amazed - it's mostly empty space! Even the CRT is tiny!

Any thoughts would be appreciated.

Gary Appel

-----Original Message-----
From: Siggi
Sent: Saturday, June 23, 2018 7:09 AM
Subject: Re: [TekScopes] TDS 380 won't trigger

Hey Gary,

the NVRAM is checksummed, and if the NVRAM fails, the scope should display
an error at power-up.
If the scope is not displaying an error, then more likely this is due to
SMD electrolytic capacitor leakage that has started shorting things and/or
eroding traces. See e.g. this <> accounting
of capacitor and other problems in 400-series scopes.


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