Agilent 34970A error codes

USMCPMEL · 03-16-2009 -- 08:56:37

I have a 34970A throwing 5 diferent error codes at me on start up. 749 742 744 745 and 746. Also so far the calibration is way out I am reading 99.64 mv when it should be 100 and it stay pretty close to that far out on the way up. .997 for 1VDC 9.97 for 10 VDC and so on. I have not gone any further because I do not know how to adjust this.

Duckbutta · 03-16-2009 -- 09:05:15

Try Agilent's web site. They have many service manuals available for free download. If memory serves, this model has been around for awhile, so your chances are pretty good that it will be available.

USMCPMEL · 03-16-2009 -- 09:19:07

Makes sense now. I looked up the codes and they are all cal data lost codes. So basically a good bit of the calibration constants have somehow been wiped out on this unit. Got that figured out now I have to figure out how to reset them all.

Snap · 03-16-2009 -- 09:36:53

Do you use METCAL? I have an automated adjustment procedure for this.

Duckbutta · 03-16-2009 -- 09:43:26

If it lost the Cal Constants, I'm suspecting that there is a Lithium battery in there that is going to need to be replaced. If you don't replace it, as soon as you turn the unit off the new Cal Constants will be lost.

USMCPMEL · 03-16-2009 -- 09:48:07

Ok anyone know where this mystery battery might be?

MRD · 03-16-2009 -- 10:08:00

it's usually a purple Sony Lithium, it's not the flat disc, it's a soldered cylinder about 1/2 to 2/3 size of a AA. Make sure you order the right version with three legs and not two.

Mark

USMCPMEL · 03-16-2009 -- 12:14:22

Thanks I did find a manual. In the back it states that the battery has nothing to do with calibration constants. It also says that if the battery does go dead u get errors codes 220 221 221 and I have none of those codes.

MRD · 03-16-2009 -- 12:40:26

Did you look in the Users Manual, 34970-90003, for the complete list of errors. The Service Manual states it's a subset of the complete list. If you look in Chapter 6, page 316, it has all the errors you mentioned:

742 Cal data lost: DCV corrections
744 Cal data lost: RES corrections
745 Cal data lost: FRES corrections
746 Cal data lost: AC corrections
749 DMM relay count data lost

Sounds like the battery to me.

USMCPMEL · 03-16-2009 -- 12:53:24

Ok. I did find a manual and found the alignment procedure. I adjusted everything and then unplugged the unit for like 10 minutes to make sure it did not lose the new cal constants. Now I have a new problem which I am probably going to start a seperate post for. Everything worked good I got this thing reading spot on except for 4 wire ohms. I can not get it to adjust and it is reading way out 1 kohms is reading 1.00185 anybody have any ideas on this?