HI ALL,
I have a HP3458A with error ERRSTR205hardware failure test value OUT OF RANGE:95"; at start up it gives also this message 110, CALIBRATION REQUIRED -- ACAL.
So following some testing results i notice that there is a problem of level of nano ampere range because i applyed 1µA it gives as follows:
Range of µA
range 1 --> 001,14432 µA
range 2 --> +01,058890 µA
range 3 --> +0,659799 µA
range of nano ampers
for 1µA injected ----> it reads 000,003nA
the 3 ranges of micron has been tested overlimit, they are ok, but the one of nano, it doesn't give overlimit even the value is greater that it's capacity.
the 2nd probelm is the resistor couldn't be measured:
i apply resistor of 2kohms ---> it gives for different ranges those values
-00,29841 OHMS
-000,30204 OHMS
-0,0003013 KOHMS
-00,000331 KOHMS / -000,00036 KOHMS / -0,0000009MOHMS / -00,000006MOHMS / -000,00001MOHMS / -0,0000000GOHMS.
The same for 9,99 KOHMS resistor it gives almost the same values.
then i found there is in front of dmm a short circuit between LO and the input of 1A/250V.
also when i lauch cal it goes out at ACAL DCI 1/10u.
I hope receiving more feedbacks about those issues.
Kind Regards
HUGOMAN