Oscilloscope HP 54112D error message

[ooorobertoooPL]

Hi, I bought an old HP 54112D oscilloscope at a garage sale. Begins the test and displays the error "system error ZERO DIVIDE 01493CH". On board processor are two empty U14 and U31 memory slots, the questions I have two slots must be empty, or not?

[wn1fju]

My working 54112D has two empty sockets just like your unit.

If you haven't already, you might try the two-key power up where you hold down the top and bottom softkeys on the right edge of the display while
powering the unit.

[ooorobertoooPL]

I tried the bottom soft key, and so
power-up self test in progress
Last loop completed: 1..12..40..50..59.60.61 end blac screnn , nothing happens ,
corrupted memory ??

[jitter]

Are those the so called "low cost" IC sockets with spring contacts (as opposed to the "high quality" type with the turned pins)?

If so, I would take out and reseat every IC in such a socket one by one to break any oxide. Worth a try as it's free...

[ooorobertoooPL]

I checked all the checkpoints , all the connections, all the elements and everything seems to be okay only U51.    And of the service book , according to the table U51 is powered by 5V for me is 15 V, during the test  DAC service should send different values and I have all the time value -9.99v . This value must be 5v or 15 v ??