Reply with QuoteThe battery is inside the Dallas real-time clock module (below the PCI slots in your first photo). The module is replaced as a whole.
MB16 battery needed
My machine won't boot up because of the CMOS battery error.
I can't find the battery on my 1987 MB16.
I found an empty circuit board traces for it on the motherboard, but it's clear that the battery was never there.
I can't find the model number of the board, and I really don't want to take it out to read the back, unless I absolutely have to.
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Re: MB16 battery needed
The battery is inside the Dallas real-time clock module (below the PCI slots in your first photo). The module is replaced as a whole.
Re: MB16 battery needed
Thank you, thank you!
I'll order this one from Amazon. It should be here in 2 days. https://www.amazon.com/Todiys-DS1288.../dp/B08LL8GL1Y
Originally Posted by CitizenOfDreams
Re: MB16 battery needed
What kind of mouse do I need to manipulate menu in BIOS?
Re: MB16 battery needed
Any standard COM or PS/2 mouse (same vintage as the motherboard) should work in those menus, I think.
An early USB mouse that had a USB to PS/2 adapter with it may work (if the motherboard has the PS/2 connector).
A modern USB mouse will definitely not work, even with the adapter.
Re: MB16 battery needed
I took out the motherboard because I couldn't get the DS12887A chip removed while installed. Turns out, it's soldered and just just socketed.
Which brings up 3 questions:
1. Can I use the battery connections next to the AMIBIOS chip to make it easier?
2. Are there any settings I need to backup from the BIOS before I unsolder the timing/battery chip?
3. How long does the DS12887A battery last on machines that are in a hobby shop and only turned on 1-2 a month for few hours?
Should I try to install a socket holder/riser to make it easier next time I have to replace the DS12887A ? If I assume this one is original to the motherboard ( dated 1993ish) then I obviously won't worry about it.
Re: MB16 battery needed
1. No, you cannot simply connect a battery to the motherboard. The DS12887A will not see it.
2. If you see the "CMOS battery error" message, the settings have already been lost, there is nothing to backup. Just in case though, enter the BIOS and write down anything that looks important.
3. The datasheet claims a minimum of 10 years of expected data retention at room temperature. I have seen Dallas chips that lasted for around 15 years. So I personally would not bother adding a socket.
Re: MB16 battery needed
Thank you.
The error said the battery low, so I should still have stuff in there.
It looked like standard BIOS screen, and from years back, I don't remember there ever being anything special, other than boot sequence and port (serial and parallel) settings such as IRQ and stuff. I don't ever remember loosing them when replacing normal batteries, but that was in standard PCs.
The board is out now.
When it was still installed, I tried to go into the settings and change things (pressed F1 to get in), but I couldn't navigate with arrows, space, tab, enter, etc.
There is a mouse cursor in the center of the screen, but obviously machine doesn't use a mouse. I went to used computer parts store and bought an old, 2 button, DB9 mouse. I plugged it into the only visible RS232 port but nothing happened.
At this point I don't know if I did something wrong and how to navigate in BIOS. I don't want to desolder the old chip without writing down BIOS settings, but I'm also unsure how to navigate the BIOS.
Re: MB16 battery needed
I might be wrong, but I don't think DS12887A has any means to report low battery voltage. The computer only knows the battery is bad when the data in the CMOS RAM gets corrupted (checksum error), or the clock resets.
Have you tried the mouse on another old computer?There is a mouse cursor in the center of the screen, but obviously machine doesn't use a mouse. I went to used computer parts store and bought an old, 2 button, DB9 mouse. I plugged it into the only visible RS232 port but nothing happened.
Was the RS232 port located on the motheboard itself, or on a plug-in card? The BIOS probably only searches built-in COM ports for a mouse.
Is there also a PS/2 mouse port on the motherboard?
Re: MB16 battery needed
- Lets hope you're wrong about the clock.
- I do not have another computer to check the mouse with.
I was using a daughterboard for the mouse. There is no direct DB9 port on the MB to plug in a mouse.
Re: MB16 battery needed
...to navigate the BIOS you need a Keyboard with an older type AT DIN plug or AT to PS2 Adapter
https://en.wikipedia.org/wiki/DIN_connector
https://www.ebay.com/itm/22511056818...Bk9SR76T6ZzgYA
https://www.ebay.com/itm/25569480676...Bk9SR9zdlZ7gYA
..as far as de-soldering the Dallas chip there are other Options to fix it. Depends how good you feel about Board Level repairs what is best to do.
Search for "Dallas chip repair" and you will see how others have done repairs
https://www.google.com/search?client...as+chip+repair
DJ
Last edited by machinehop5; 09-03-2022 at 01:57 AM. Reason: added Links
Re: MB16 battery needed
Thanks for the replay. I do have a keyboard and use it during normal operations.
For some reason, it works to enter BIOS (F1), but doesn't do anything once in it. No letters or arrows work, and the only way to get out of BIOS is to power down the machine.
I have seen few videos on the battery soldering to the chip, but in all cases the chip was removed, and for safety, I would want to do that as well.
I actually bought a 2-pack from Amazon, so I do have a new chip. That's why I was asking earlier about installing a chip base, to allow for future quick replacements, but based on feedback (and expected 10-15year internal battery life), I'll just install the new one.
https://www.amazon.com/dp/B08LL8GL1Y...roduct_details
Re: MB16 battery needed
These machines were DOS basic right?...does using the holding down Delete method work differently? Or same as F1 when booting up?
Another question is does your machine have any Software Disks from Milltronics?
The reason I ask is .... have seen in the past by rerun the PLC Exe program the Battery Low alert resets. Double check the Verison numbers before trying this one...dont want to brick the controller
DJ
Re: MB16 battery needed
I did not get any disks with it. :-(
Yes, it's just a DOS.
I tried holding ESC, DEL, F10 buttons without change.
I obviously don't care about the clock itself -- I just want to use my damn machine.
I don't think we can use it without booting up, can we? I mean, I know I can move the bed, but don't know how to move Z or if the spindle would fire up with the side button (on the console).
These machines were DOS basic right?...does using the holding down Delete method work differently? Or same as F1 when booting up?
Another question is does your machine have any Software Disks from Milltronics?
The reason I ask is .... have seen in the past by rerun the PLC Exe program the Battery Low alert resets. Double check the Verison numbers before trying this one...dont want to brick the controller
DJ
