VOGONS


First post, by AskNotes

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Rank Newbie
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Newbie

Just a happy note about the first real-time clock mod I just did 😀

Recently I got GA-586HX Rev 1.53 motherboard. Wanted to test it with Pentium 166 CPU I had. Noticed that in Bios I can set whatever I want but only the clock/date is saved and nothing else, also the clock was not ticking. It had Benchmark bq3287mt Real Time Clock module. Luckily, on this motherboard it was in a socket, so that solves a lot of trouble.
So I had an option to order a new one or try to make an RTC module mod and add an external cell battery. I have never done such a mod so of course, I decided to try 🙂 Mostly everyone on the internet suggests to Dremel out the side of the module to access power pins and solder their wires from the coin battery holder.
I decided to go slightly another way.
I took an electric drill with a small disk with sandpaper attached to it. Then I fastened the RTC module in a vice and started sanding off from the top hoping to get to the battery and remove it. Soon I started to see the battery.
The battery was not going out, so I have decided to sand more and it was a bit too much – I have damaged crystal on pins 2 and 3. Oh well, all was left it to try to sand out all the epoxy until IC will be accessible and see if I can fix it.
After some time, when there was little epoxy left, it started to crack and I could easily remove it with a sharp knife.

Then I cleaned everything out and in my used electronic components box found one crystal ( I have no idea where it was from and what model it was, but it just looked similar so I have decided to try ), and a coin battery holder.
Soldered crystal to IC pins 2 and 3 and then glued and soldered battery holder to IC pins 16 and 20. And what do you know, it worked!!!
The clock started ticking and all settings I have made were stored in CMOS.

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  • 20201022_202831.jpg
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    Benchmark bq3287mt Real-Time Clock module taken out of the socket
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  • 20201022_204453.jpg
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    Sanding off the top of the Benchmark bq3287mt Real-Time Clock module
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  • 20201022_210825.jpg
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    Benchmark bq3287mt Real-Time Clock module with epoxy removed
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  • 20201022_214809.jpg
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    Benchmark bq3287mt Real-Time Clock with new crystal and battery.
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    Fair use/fair dealing exception
  • 20201022_214814.jpg
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    Benchmark bq3287mt Real-Time Clock with new crystal and battery.
    File license
    Fair use/fair dealing exception

From ZX Spectrum to IBM PS/2 70 and so on. http://asknotes.com/

Reply 1 of 1, by Horun

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Rank l33t
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l33t

Well it is not pretty but if it works then you did good ! I always just dremel to find the battery pins, severe the GND one and solder the new battery holder (or wires) to the "now" exposed pins.
There is really no need to remove the old battery if you use an epoxy or black silicon to cover up the dremeled side as any possible old battery corrosion will remain inside the RTC.

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....