Original site
The Situation: You have either a PS/2 25-286, 30-286,
55 or 65 which comes up with a "165 configuration error" and fails to
keep the setup once been shut off again.
Click to enlarge
Drawing © 2006 by Peter H. Wendt / Germany
Well - these have the dreaded Dallas DS1287 "all in one" Real Time Clock (RTC) chip with integrated Xtal and battery. Now the battery is dead, configuration is lost after relatively short time again and you get error-codes constantly. A really new, fresh and unused chip is hard to get. Even its successor DS12887 is pretty hard to get and darn expensive. At that point you wish you could add an external battery. But you can't. There are no provisions for one. Not yet. The Action: Have a look at the graphics below..
Basically the DS1287 is a DS1285 chip, where the pins for the
xtal-connection and the battery are bended upwards. Then the battery
and xtal are placed atop of the chip, connected to the pins and
everything is covered with a pretty rigid protective compound.
The DS1387 is the same chip with an additional integrated 4K SRAM. All described modifictions apply to this chip as well. The only things you need to do is:
Possible Results Reworked chip inside a Mod. 65SX Side view of modded chip. Note the battery holder ! Curiosity killed that cat. After the dust cleared ..... All pictures © 2006 by Moritz Hoffmann & his father / Germany Some more Feedback !
On March, 23rd, 2007 Chris (xrisl [at] yahoo.com) reported the
following:
My old computer has been out of action for months, but this week I got
it going again by following the instructions on your webpage "Reworking
the DS1287 RTC chip".
Above 2 pictures © 2009 by D. Howe / USA
Without that webpage, I would never have thought of repairing it like that! So you have my thanks and gratitude for putting that idea on the web. (Incidentally, my computer is an Compaq 386N, which seems to date from about 1990). With thanks, Chris. On April 24th, 2007 Gary Jay in Ohio, USA (siffert [at] usa.net) reported the following: Hi Peter...just thought I would let you know that I got the DS1287 reworking on my first try! I used an iron file that was about the exact width I needed and just slowly went back and forth about 50 times until I saw the metal and then used sandpaper the rest of the way. Soldered and used a CR2032 battery with holder on top of the 1287. Worked like a charm and would like to thank you and I am very grateful I stumbled on your web site. I could not have gotten my Compaq DeskPro 286e back to clock life back without you! Regards, Gary William Walsh, USA finally succeeded in the DS1287 rework His success-story can be read at his Dallas Rework Page William Walsh, USA also modified the DS1387 chip The DS1387 is technically near-identical to the DS1287, but has an additional integrated 4K SRAM. William Walsh did the DS-Rework to get an external battery to it as well. His report can be found at his DS1387 Rework Page Really good job, William ! On January, 7th, 2009 Emmanuel Da Piedade (emmanuel.dapiedade [at] gmail [dot] com) from France wrote me: Hi Peter, My name's Emmanuel, and I live near Paris in France. I just want to tell you that I succesfully used your DS1287 rework How-to. You did a great job! Thank you! My IBM PS/1 m2011 works fine now! You can see the result here (sorry, the text is in french) : Here Best Regards Emmanuel D. Howe, USA did the modification for his Dell 4100 computer He reported on February 16, 2009: Dear Peter... I bought an old DELL 4100 computer about 7 years ago to play with because it had an 80486DX4 chip in it. Then circumstances kept me from working with it until now...the computer spending all this time in my garage. A couple weeks ago when I finally got around to hooking it up...I discovered that the RTC chip was dead. Can you imagine my amazement and relief when I discovered your web site describing the DS1287 rework process. I used a medium sized flat file...a little less thick than the distance between two pins...to file down to the two battery pins. I soldered a #22 solid wire to each of the battery holder pins, then glued the holder to the DS1287 case using model airplane plastic cement. Attached the two wires to the exposed pins and put the new lithium cell in the holder. Voila! It works like a champ! For anyone who attempts this mod...don't make my mistake with the plastic glue. It sets too fast!...less than 15 seconds. Go with the hot glue. So...Peter...Thank you very much for putting this mod on your web site. I appreciate it greatly. With regards, D. Howe dougnflo [at] comcast [dot] net Kalamazoo, Michigan, U.S.A. |