Tektronix S1001 DIP switch: Open pin 3 to boot for fast self-test (TDS 744, 744A, 684A, 784A)

Normally for most TDS 500 series oscilloscopes, the DIP switch (S1001) typically all closed for normal operation. The only described use in the service manual is opening pin 6 and 7 to reveal the hidden composite test pattern screen for display adjustment.

However, I got a TDS 744 scope that boots very slow. Almost 5 mintues! To the extent that it’s unbearable. Initially I thought it’s just the non-A type booting slow. Nonetheless, I got a chance to open up another TDS 744A with boots much faster (in half a minute) with calibration seals on, and I noticed the pin 3 of S1001 is opened. Initially I thought it was out of place so I closed it again. Guess what? A slow 5 minute boot sequence!

I suspected opening pin 3 of S1001 puts the oscilloscope in the quick boot mode. I experimented with the pin 3 opened and manually initiating the full blown self-test (utility menu). Turns out I was correct! The full self-test is 5 minutes!

Since it was the settings from the calibration house, I looked up the TDS 744A/684A/784A service manual and noticed that the factory default is with pin 3 opened, while the old TDS 544A manual says pin 3 is closed. I suspect that the self-test for the new models 744/744A/684A/784A is unbearably long that the Tek decided to have it disabled for boot-up self-test.

In any case, try opening pin 3 to have the scopes boot faster!

 

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