Datron 1271 repair

[picburner]

I also noticed a discrepancy between the dump generated by the pelule and rigrunner scripts: in practice from the address 0x0000 to 0x07ff they are identical instead from 0x0800 to 0x1fff they differ completely.
I have a 1271 with firmware v2.10 and the last digital pcb.
As soon as I can I try to do another check with TheSteve script's.

[Mickle T.]

Does anyone have an idea how to enable an option 40 "Comprehensive Ratio" in Datron 1271?

[picburner]

I can tell you how to enable option 70: with the jumper highlighted in the picture (adding the missing components of course in my case only the AD7545).
Only one jumper on the side remains, which perhaps could activate option 40? (I am missing 2 relays and 1 coil and I can't try it).

[picburner]

I just did a test between the three different scripts of the three authors.
Pelule and TheSteve's scripts give identical results, rigrunner script's has the difference mentioned above.
Attached are the dumps obtained and the comparison.

[rigrunner]

Looks like my original order is the culprit.

[TheSteve]

End of the day if someone was depending on the data they had dumped in the past using the script it can be corrected with a hex editor. All the proper data is still there.

I'll have a further play with the 4920M and the DUMP? command but so far giving it any arguments generates an error.

[leighcorrigall]

Can someone please upload both the raw DUMP? output (e.g. 0040 74FF 75FF 74AB 75B5 74FF 75FF 74D4 75C4) and the BIN file so that I can validate a modernized Python3 script? Samples should only be given by members that have successfully uploaded their calibration data to the instrument.

For example, pelule has provided both "NVRAM1281.BIN" and "DUMP_NVRAM [org].txt". I do not know yet whether the data is valid, but it is a start.

https://www.eevblog.com/forum/repair/datron-12811271-cal-ram-backup-how/msg1390517/#msg1390517

Thank you!

[pelule]

HI    leigh,
unfortunately i had a stroke which caused a left paralysis. so i had to stop all my hobby activities for 1/2 a year and still working aon a slowly recovering.to help you going on, i would recommend to get in contact to ilStephen Ireland (ste@umrk.org), heorked on the datron nvram- adapter see:  https://xdevs.com/fix/d1281/#adapters, see also rigrunnerhttps://www.eevblog.com/forum/repair/datron-12811271-cal-ram-backup-how/msg1390517/?topicseen#msg1390517.
hope this help a bit. br PeLuLe

[leighcorrigall]

Hi PeLule,

Sorry about your health. I hope you get well

I was able to verify my new script based on rigrunner's script (and TheSteve's xvi11 library adaptation) yesterday:

Python 3 scripts: https://www.eevblog.com/forum/metrology/datron-1281-repairmaintenance/msg3876473/#msg3876473
verification: https://www.eevblog.com/forum/metrology/datron-1281-repairmaintenance/msg3879275/#msg3879275

Regards.

[little.tesla]

I would like to share with you an updated version of the python scripts for dumping the nvram. The dumped content has been confirmed by comparing it to the actual content of the SRAM.

The FRAM adapter from xDevs works like a charm. Just remember to cut pin 26 of the programming adapter (Pin 26 is A13; Not needed anyway).
https://xdevs.com/fix/d1281/#adapters

For programming the FRAM, select as a device DS1230. Remember to ONLY program the range 0x0000 to 1FFF. If you use the full memory range of the DS1230 for programming, the content will not match your NVRAM binary (probabbly 0xFF).

A final note: On my unit I run into the error code 2022 NV RAM write failure. Which was related to the cal key switch on the rear to have bad electrical contact. Since it was not repairable (missing parts) I've replaced the key switch with SRL-5-E-S-2-850 from Mouser. It's fully compatible with the original, key fits the old switch as well.