Electronics > Repair
HP 3458A - Fails Slave Test - Convergence
Ade911:
--- Quote from: Ade911 on May 16, 2023, 07:20:42 am ---Thank you all for your advice and feedback, yes not proud of what i did but you sometimes get to a point where you do big changes usually around 2AM.
I don't have a GPIB interface so hence the decision to very carefully remove the Dallas chips and copy. I've attached copies of the data uploaded from the chips, I believe its still ok unless I dropped a bit somewhere or you think otherwise.
Re your advice and comments below, Ill carry these out today and report back.
For debugging the input amplifier it would help to start with the non AZ mode, though with a stable 0 V at the input it would not make a difference - shorted together all 4 inputs and selected azero off
For the 10 V range pins 1 and 2 of U103 should be at the negative rail, some -18 V. - correct
Pin 14 should follow TP100 = the amplifier output. - Pin 14 and TP100 are sitting at 0 volts
TP101 as the buffered feedback signal is also of interest. - sitting around 0 volts
--- End quote ---
IanJ:
--- Quote from: Ade911 on May 16, 2023, 07:20:42 am ---Thank you all for your advice and feedback, yes not proud of what i did but you sometimes get to a point where you do big changes usually around 2AM.
I don't have a GPIB interface so hence the decision to very carefully remove the Dallas chips and copy. I've attached copies of the data uploaded from the chips, I believe its still ok unless I dropped a bit somewhere or you think otherwise.
Re your advice and comments below, Ill carry these out today and report back.
For debugging the input amplifier it would help to start with the non AZ mode, though with a stable 0 V at the input it would not make a difference.
For the 10 V range pins 1 and 2 of U103 should be at the negative rail, some -18 V.
Pin 14 should follow TP100 = the amplifier output.
TP101 as the buffered feedback signal is also of interest.
--- End quote ---
Your U132 (Calram) is all FF.....so deffo didn't read properly.
The other two U121(L) & U122(U) Settings RAM look like they might be ok.
Ian.
Ade911:
Ian thank you for checking , not sure what happened there , I checked all the fibre links , then it died before I swapped them out.
I appreciate I need the system calibrating but can you get copies or does any one have a copy I cold down load to the device to see if this helps my unit at all or do i need to pay big bucks to get the unit fully calibrated again :(
moving on Dataman S4 programmer nice kit but i wouldn't use it enough to pay for itself , ill keep an eye out on eeee-bay.
Any further feedback will be most welcome please
coromonadalix:
i hope you know how much this baby will cost to calibrate officially by Keysight ??
You have a cadillac of meter, and the price will go with it, hoping you dont have any A3 board problems on u180 if i recall
alm:
--- Quote from: Ade911 on May 16, 2023, 07:32:08 pm ---I appreciate I need the system calibrating but can you get copies or does any one have a copy I cold down load to the device to see if this helps my unit at all or do i need to pay big bucks to get the unit fully calibrated again :(
--- End quote ---
Unless you have a friend who's a serious metrology geek, you will need to pay big bucks to get it adjusted and calibrated to factory specs. But the adjustment procedure is quite straight-forward if you don't care about accuracy (see the calibration manual), and since you have nothing to lose at this point in terms of accuracy, you might as well calibrate it to a very basic short, 10V from a bench supply and a stable(ish) 10k resistor. Just keep in mind that best possible end result is a meter with the accuracy of a 3.5 digit meter. You will want to first establish that the hardware is fully functional and stable before spending any money on having it adjusted.
Please start being more methodical and read the huge amount of information that is out there before touching anything, because just losing the calram will have probably have set you back to the tune of $1k. Buying a GPIB interface would have been cheap compared to this.
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