开云体育

Hi,
I bought a broken HP8757C with backup battery leak problems.
The errors due to power supplies and broken tracks on the PCB have been resolved (I hope).
Only one error comes back to me: Error 01 > DAC BIT CHECK Fail > SWP DAC Fail 0000 00000 0010
I tried the whole procedure in the service manual but nothing comes of it.
All references and voltages are OK.
SWP DAC Fail 0000 00000 0010 -- Where can I look for this address?
I attach photos of the error.
Thanks for any suggestions.

Maurizio

Thanks Hb9ica but the table you sent me refers to the main Error as in the first picture.
the second step is "INSTRUMENT VERIFY" and the result is " DAC BIT CHECK",
the third step is "ADC TEST - DAC BIT CHECK" and the result is " SWP DAC Fail 0000 00000 0010 "
Where can I look for this address?
Thanks for any suggestions.
Maurizio

Hi Maurizio,

The result is voltage setpoint from the 12bit DA converter on A4 board.
I assume you should test this board, and measure the sweep at this bit setpoint.
I have read the section 8 SWEEP DAC, in the 8757D service manual (same A4 board as in 8757C).
All other test are OK? then the interface between A3 and A4 should be ok.
Have a look at A4 board and special the DAC section and scope the sweep output..Plse perform power supply and sweep DAC gain calibration (follow section 5)

Regards Guido

Hi Guido,?
I'll do the checks you recommend.?
Thanks you very much.?

Maurizio?