HP 3562a "Bad Auto Sequence Table" error - Page 1
Forum section: electronics / repair

author: Keicar
author_rank: Regular Contributor
timestamp: November 07, 2016, 05:09:59 am
content: I have a HP3562a that has started displaying the "Bad Auto Sequence Table" error message at startup - it was doing this when I first acquired it & I replaced the lithium battery (I think it's on the A2 board) - and the problem went away. Now, around 12 months later it's started doing it again - seems a rather short life for a backup battery so I'm a bit suspicious that something else might be causing it. I have yet to open the unit or test the state of the battery at this stage, but I was wondering if anyone knew of another possible cause for this error (bad RAM perhaps, or maybe excessive current draw on the backup battery leading to its early demise?) - has anyone else experienced a similar problem?Cheers,Karl.

author: Simon Spiers
author_rank: Regular Contributor
timestamp: September 29, 2017, 03:09:29 pm
content: I have the same problem on the same DSA. Was it just the battery?

author: innkeeper
author_rank: Unknown
timestamp: September 30, 2017, 06:51:31 am
content: couple of thoughts...on mine, I had the same error when the battery voltage got low, before i replaced it as well.When i got mine, someone had put in a 2/3AA sized 3.0vso between that and the voltage drop across the diode to the memory, it didn't have a long life before it wasn't maintaining the 2v needed at the memory to hold data.what voltage battery did you use when you replaced it. also what size / capacity battery?I would go in and at least check the voltage on the battery and see if that is it for sure.oh probably not an issue, but there is a jumper there, J21 (had to look the number up) anyway make sure its on N normal and not T test. that disables the battery.also might be a spot for potential losses if things got corroded there.if it is any help,i used a 3.6v Lithium thionyl chloride 2400mah AA sized XENO brand to replace it. and all has been good so far.XENO just what my local supplier had and didn't wanna wait for a better quality SAFT battery.

author: Simon Spiers
author_rank: Regular Contributor
timestamp: October 03, 2017, 03:15:52 pm
content: Yes, the battery corrects this error. Unfortunately it has other errors not so easy to fix. And now the display section 1345a has died

author: Alex Nikitin
author_rank: Super Contributor
timestamp: October 03, 2017, 03:33:05 pm
content: Quote from: Simon Spiers on October 03, 2017, 03:15:52 pmIs it the same as in the HP3563A? I have a used working display assembly for it just gathering dust...CheersAlex

author: innkeeper
author_rank: Unknown
timestamp: October 04, 2017, 03:54:07 am
content: another option is putting a color lcd display and making us all jealous.http://www.simmconnlabs.com/2001/2073.htm

author: Keicar
author_rank: Regular Contributor
timestamp: October 04, 2017, 04:45:09 am
content: I have to confess I haven't bothered to open up the unit since - I'm just living with the error message. Although I've had a couple of start-up calibration failures recently (on both occasions it worked OK on the second attempt) so I suspect some more investigation will be required soon <sigh>.My unit was supplied with a 3.0V Varta battery installed, I used a 3.6V Tadiran as the replacement - it measured 3.61V when installed.Cheers,Karl.

author: Alex Nikitin
author_rank: Super Contributor
timestamp: October 04, 2017, 12:02:48 pm
content: Quote from: innkeeper on October 04, 2017, 03:54:07 amNot all of us.CheersAlex

author: innkeeper
author_rank: Unknown
timestamp: October 04, 2017, 11:30:40 pm
content: Quote from: Alex Nikitin on October 04, 2017, 12:02:48 pmtotally jealous

author: innkeeper
author_rank: Unknown
timestamp: October 04, 2017, 11:32:42 pm
content: Quote from: Keicar on October 04, 2017, 04:45:09 amhmm...yea that should have lasted quite a while like ~10 years.

author: ahannan
author_rank: Newbie
timestamp: October 08, 2017, 04:21:49 am
content: Thanks for the posts! I just picked up one of the 3562A DSAs and it had that message as well. Sounds like an easy fix. FWIW, a clip from the schematic shows it should be 3.9V, so anything lower just wouldn't last as long ... I found some batteries 3.9V 2Ah for $50, so I might do something different too, lol. Update: I ordered the Tadiran Karl suggested. TL5104P for $10 shipped BatteryDepot via Amazon.

author: ahannan
author_rank: Newbie
timestamp: October 08, 2017, 05:19:36 am
content: Quote from: innkeeper on October 04, 2017, 03:54:07 amUpdated linkhttp://simmconnlabscom.ipage.com/home.html/2001/2073.htmlYeah, I want one, but I didn't pay that much for the 3562A, lol. It also lists other pieces of HP equipment it can be used on.

author: innkeeper
author_rank: Unknown
timestamp: October 11, 2017, 11:58:58 pm
content: Quote from: ahannan on October 08, 2017, 04:21:49 amvery cool. that should work great. let us know how you progressI calculated the lifespan of the 3.6v 2400mah battery i used to be around 10 years.i wish i had not been in a rush myself as i would have gone for the uber high quality Saft LS1500-AX or the Tadiran TL5104P which is also excellent battery.the XENO battery i used is a XL-060FAX - its a no-name brand my book, but it does work.just an fyi, i thought the same thing, that the 3.9v batter would give me extra life, but not so..i dug into the discharge curves before i got my battery, it tuns out the 3.9v Thionyl Chloride drop down to the same nominal voltage as the 3.6v and 3.4v batteries after they discharge 10-20% so the lifespan is identical.the 3.9v lithium Thionyl Chloride batteries ar actualy Thionyl Chloride with bromine chloride which gives them a higher initial voltage but after 10-20% acts the same.oh, also those 3.4v batteries seem to start at 3.6v and drop to 3.5 over most of ther lifetime at light loads .. so .. they seemed to be spec'd at ther rated voltage at higher loads, but the discharge curves seem the same to me.add in the fact the dropoff curve at end of life is extremely sharp and bottom line for us, the 3.4-3.9v lithium Thionyl Chloride batteries provide the same longevity for any given mah rating.so might as well stick with the somewhat standard 3.6V ones.I also dug into the schematic and memory specs also to see if there were any concerns.. bottom line any of the AA 3.4-3.9v lithium Thionyl chloride batteries are fine and not near or over to the maximum voltage nor do they go below the needed voltage until they have reached there end of life capacity.