Datron 1281 error help please - Page 1
Forum section: electronics / testgear

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: July 10, 2020, 03:31:49 pm
content: I am working on a new to me Datron 1281, it is one of the original brown ones with the first Digital board iteration.When I received it the unit functioned however it had a pronounced drift issue on DCV. It did not throw any error codes. The power supplies were measured, they were sort of OK, they had a fair bit of ripple. I ended up having to replace all the electrolytics since they were out of tolerance value and/or ESR. I did the all the tantalums while I was wielding the soldering iron............All power supplies on the Digital and DC board are now spot on and clean. The backup battery on disassembly read 3.6V.Putting it back together I now have 2 errors, on power up I get a very brief error message of "Secondary N.V. checksum Error2111" then it defaults to "Measurement Corrns, Invalid 2021" The Error 2111 is different from the manual. The manual says 2111 "Fuse is open circuit" so that is confusing.....At this point have little control over the unit. Pushing the CAL button will briefly give me a different display that I can discern the CAL due date is garbage before the display switches back to the Error 2021. Only thing showing on the left display is "V"From reading other people's experiences I am wondering if the CAL RAM somehow got corrupted during my work..This is my first experience working on the 1281 so any help or ideas would be greatly appreciated.

author: TheSteve
author_rank: Unknown
timestamp: July 10, 2020, 07:35:52 pm
content: It does seems quite likely the battery backed ram was corrupted - might be time to disconnect the battery and perform a full(extended) cal.

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: July 10, 2020, 07:37:53 pm
content: Have you ever used the FRAM adapter from XDEVs for the CAL-RAM?

author: TheSteve
author_rank: Unknown
timestamp: July 10, 2020, 07:39:15 pm
content: I haven't. I have several FRAM devices in stock but haven't wanted to have to perform a full re-cal of my 1281.

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: July 10, 2020, 07:54:23 pm
content: I guess I'll have to get my feet wet and order some boards and chips. Cheapest is Newark $22/ea.This thread details backing up the CAL-RAM so that it can be programmed into the FRAM...........If I have to do a full cal I may try upgrading the firmware from 2.03 to 3.12......... Thoughts??

author: Kleinstein
author_rank: Super Contributor
timestamp: July 10, 2020, 08:56:27 pm
content: The full calibration may include measuring the transformer based divider for the ACAL procedure. So this may require having really accurate reference voltages to get back the full accuracy.A backup of the residual cal ram contend is definitely a good idea.

author: TheSteve
author_rank: Unknown
timestamp: July 11, 2020, 12:25:46 am
content: I did back mine up. Another thing that slowed me down is that a TL866A/CS/PLUS won't program a the needed FRAM.

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: July 11, 2020, 02:06:39 am
content: Hmmm... that is the one I have, what is an alternative?

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: July 11, 2020, 02:35:46 am
content: Answered my own question, I just took a look at their latest support list for the TL866II Plus and it now supports the RAMTRON FM1808B in DIP and SOIC as of March:http://www.xgecu.com/MiniPro/TL866II_List.txtIt looks like they have released a new one, T56, they don't offer a comparison though to the TL866II Plus.....http://forums.xgecu.com/redirect.php?tid=19&goto=lastpost#lastpost

author: TheSteve
author_rank: Unknown
timestamp: July 11, 2020, 06:35:48 am
content: This is excellent news! I asked them to support the Ramtron devices a few months back, I guess they listened!I have a heck of time downloading the new software these days, ever since they added a forum. It downloads extremely slow and frequently fails.Assuming it will download I will test it out and report back.I have adapter boards already made to use them in my 3458A's as well.

author: doktor pyta
author_rank: Frequent Contributor
timestamp: July 11, 2020, 06:50:21 am
content: I hope You read this:https://www.eevblog.com/forum/repair/datron-12811271-cal-ram-backup-how/msg1390517/#msg1390517

author: TheSteve
author_rank: Unknown
timestamp: July 11, 2020, 07:09:47 am
content: Had to use my cellphone to download the newest TL866 Plus software - version 10.22.I am pleased to report I can now read/write my FM1808's successfully. I will be installing them into a 3458A when I have time using a DIP adapter board. Will ponder if I want to mod the 1281 as well or wait until it needs other service.btw, my FM1808's(in DIP) came out of China and all appear to work fine.

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: July 11, 2020, 03:28:18 pm
content: Just read that last night, I'll explore the contents this weekend.... in between the household chores!

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: July 11, 2020, 05:46:02 pm
content: I did try clearing the secondary NV RAM area (since that is what the brief message gave me) but then I was getting the message about the primary NV RAM. So I have cleared the whole NV RAM. Put back in the serial # and line freq, no other errors....It was interesting that the error message constantly asserts itself as you are attempting to clear the NV RAM so one must be very quick on the fingers!!I did try backing up the cleared NV RAM after putting in the serial# and line freq, but it wouldn't finish which is interesting........