dallas rtc hack - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2021, 02:10:26 pm
content: Hi all,i have just renewed the rtc in my hp 54503a scope,its a dallas DS1230Y-100 ,its the one containing 2 battery cells,i would like to hack the old one to fit a battery holder,has anyone done this on this rtc,i see hacks for others but they are different chips,the potting is like concrete,heat doesent soften it,firstly,is there a replacement for this ic that can have the battery hacked,or any way of removing the potting compound,its as hard as glass,i have concentrated hydrochloric acit but guess that will just dissole the pins and leave the potting alone,any ideas or is it a no go?,tia paul m3vuv.

author: ESTechnical
author_rank: Contributor
timestamp: December 15, 2021, 02:50:00 pm
content: We found some success with removing very hard epoxy potting with "paint panther" paint stripper. It's not very exact, just makes the epoxy mushy and possible to remove it.Good luck!

author: retiredfeline
author_rank: Frequent Contributor
timestamp: December 15, 2021, 02:58:25 pm
content: Hmm, a search says that chip not a RTC but NVRAM...

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2021, 03:12:47 pm
content: yes its nvram not rtc,my mistake.

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2021, 03:14:13 pm
content: Quote from: retiredfeline on December 15, 2021, 02:58:25 pmthats a thought,i didnt think of that,i will give it a go.

author: Ian.M
author_rank: Super Contributor
timestamp: December 15, 2021, 03:34:05 pm
content: Its probably simply aDS1210orMXD1210NVRAM controller and a 32Kx8 CMOS SRAM. Unfortunately DS1210 is discontinued but some suppliers have it N.O.S. MXD1210 is still current production.XRAYs of a DS1230Y-120 can be found here:https://www.antiqueradios.com/forums/viewtopic.php?f=8&t=352206They aren't quite good enough to plot out exactly where to mill to break and reconnect the Vbatt1 and Vbatt2 connections, but are enough to narrow down the possibilities.

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2021, 04:01:46 pm
content: well ive manages to carefully grind away the potting on the top of it,it seems there is a small ic on the underside and what looks like a bigger one topside as the connections to it were showing,back to the underside,i uncovered the 2 batterys,measuring them showed .4v,although they seemed too be connected in parelell,can anyone confirm this?,if so it should be quite easy to disconnect one leg of each and fit a cell holder on the top of the unit,doesent matter if it works as the scope is fine with the replacement fitted but be good to have a spare,btw the replacement is now fitted in a socket.

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2021, 04:02:30 pm
content: will post pics later,it may be of use to someone.?

author: Hamelec
author_rank: Regular Contributor
timestamp: December 15, 2021, 08:38:49 pm
content: maybe this is helpful:https://www.eevblog.com/forum/blog/eevblog-615-prema-6047-multimeter-followup/25/

author: m3vuv
author_rank: Super Contributor
timestamp: December 18, 2021, 12:38:16 pm
content: heres mine so far

author: m3vuv
author_rank: Super Contributor
timestamp: December 19, 2021, 01:11:24 pm
content: heres my finished go at doing this,not pretty but so what if it works!

author: coromonadalix
author_rank: Super Contributor
timestamp: December 19, 2021, 01:37:20 pm
content: But on one picture we seen the substrate ic, the pin legs going to it ??you destroyed the chip ??

author: m3vuv
author_rank: Super Contributor
timestamp: December 19, 2021, 01:44:07 pm
content: on close inspection it looks like all the pins look ok,as soon as i saw them getting exposed i stopped grinding,we will see!

author: urlkrueger
author_rank: Contributor
timestamp: December 20, 2021, 04:40:42 pm
content: I replaced the Dallas DS1225Y-200 64k IC in my TEK 2465B with a Cypress FM16W08-SG 64k IC as detailed in the forum under 2465 repair.It was a pin-for-pin replacement with no modifications required.I breadboard up a simple little circuit using register IC's and an Arduino to read the Dallas chip and program the Cypress chip.Couldn't have been much easier.Could you do the same using an FM18W08-SG 256k IC?