3458A problems with AC voltage measurement and with the ACAL AC procedure

[Denisok09]

Good afternoon!
I have a Keysight 3458A and it has problems with AC voltage measurement and with the ACAL AC procedure.
When powering up the 3458A, the error "110, "CALIBRATION REQUIRED – ACAL" " occurs.
When I run the ACAL 2 procedure " ACV flatness, gain, and offset” messages are displayed on the 3458A screen:
ACAL ACV RATIO 1;
ACAL ACV RATIO 2;
ACAL ACV RATIO 3;
ACAL ACV RATIO 4.
When the ACAL procedure is completed, the "ERR" symbol is displayed on the 3458A screen. There are three errors:
209, “Hardware failure-internal overload: 228”;
210, “HARDWARE FAILURE- CALIBRATION REQUIRED”;
101, “Calibration ERROR“.
The 3458A calibration manual on page 100 specifies const_id “228”, Description “ab ratio”, Constant derived from”ACAL AC".
CAL? 288,0   0
CAL? 288,1   -7,129796677E+04

Please help me understand the issue.

P.S. I apologize for English – I use an automatic translator.

[Dr. Frank]

I did not find any hint in the schematics, what ab ratio, related to CAL? 228, could mean.
MOn my 3458A, CAL? 228 equals about 370.345E3, or so.

Maybe there's an error in the ACV path, therefore please apply several AC volatges, use the different modes, and check if you find any fail measurements. Then we can proceed from then on

Frank
 

[ManateeMafia]

I had a similar issue several years ago. I can't remember know how I determined which range was being adjusted, but I narrowed it down to C104 which is a 400pF capacitor. In-circuit it measured 200pF and I removed it. I measured it again and got the same results. I replaced it with one from a donor A2 pcb and it started working after that.

I recommend probing the capacitors first as that would explain the overload error. C104 is an odd value and looks like a SMD part with legs soldered to it.

Good luck

[syau]

Sorry for digging out this old thread.

I got a 3458A with exactly the same issue, replaced the EL2039 from Utsource fixed it.