Hello Frank,
Sorry I should have shared more testing results.
A3 Board
U230 20M oscillator OK, U131 OK , signal CK10 OK [ Not a square wave but still a clock pulse] .
U211 , 212 change state during reset or changing front panel buttons, not sure if they have anything to do with how U210 functions.
Unplugged P2 and P1 from the AC board to see if anything was affecting the signal DCCK_F [sitting at 5V]
Where can I find the pin configuration of U210, I tried google but failed, guess Pin 11 U220 is acceptable - no clock , sitting at + 5V. U220 Pin 19 has a +5V clock pulse [more like a saw tooth]
Good catch Frank, still learning from the master.
Is this signal generated in U210 or U220 ?
Tx Ade.
Pin configuration of U210???
It's on sheet 1 / 2of A3. What do you expect more?
It's a hp programmed Gate Array, in my 3458A it's an ORBIT 6968A, don't know anything about this device.
I have not measured inside my 3458A, but maybe the clock Pin 31 for the SR chain is only output, when needed. (*) Please scope on that pin, while you RESET the instrument, if there is an initial activity.
What about pin 73, now? Is there a clock, or not?
The 3458A currently does not work at all, anymore?
Frank
(*) That might be reasonable, so not to disturb the analog part by RF emission, during sampling.
Hello Frank,
I have the schematic , but when you said scope on pin 73 of U210 i was not sure where pin 73 is. I tried last night on paper to draw each pin and work out after Pin 1 where pin 2,3 and so on was but it made no sense so looked for the basic pins you mentioned connected to DCSTB_F, DCDA_F, DCCK_F.
Pin 73 U210 - Pin 11 U220 , checking on Pin 11 U220 - power on goes high, goes low just before a failure of hardware Beep. Replicate by resetting the front panel , goes low just for a ms or so.
Same error, as before;
202 Hardware- slave test convergence
110 Calibration Required - SCAL
Now checking to see why U220 voltage is not smooth on the chip pins but on the supply its smooth.