FACLON - ST MK48T87B-24 - TIMEKEEPER chip

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francouai
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FACLON - ST MK48T87B-24 - TIMEKEEPER chip

Post by francouai » Sun Nov 11, 2018 7:08 pm

Hello guys!

My Falcon do not save keyboard layout, time and date.
I changed the NVRAM battery for a new one, same brand and ID, "ST MK48T87B-24".

At the rebuild, I'm still not able to save TIME and Date and I'm wondering if this Chinese seller did not F.K me. :oops: (10euros)
On the chip, it say "LITHIUM BATTERY", mean the ATARI have to recharge it for few hours before?
Or it should be plug&play directly?
It is a BATTERY or a CELL inside?

How to test this NVRAM chip?
Should I have 3 volts somewhere on PIN?
thanks
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exxos
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Re: FACLON - ST MK48T87B-24 - TIMEKEEPER chip

Post by exxos » Sun Nov 11, 2018 9:49 pm

You need to look here for software first viewtopic.php?f=25&t=30 to reset it.

You may have bad RTC module, or in most cases broken tracks while removing old RTC chip.. also some RTC chips don't work in all Falcons.. nobody knows why.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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francouai
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Re: FACLON - ST MK48T87B-24 - TIMEKEEPER chip

Post by francouai » Mon Nov 12, 2018 7:21 am

I used NVRAM/centek to reset it.
but it doesn't hold the date/time.

I'm wondering if I should take the measurement of +3volts on the PIN 24 from the NVRAM module without connected it?
looks like it is a cell inside, not a battery.

I bought another block from a Polish online seller but it will be a MAXIM-DALLAS DS12887+
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Re: FACLON - ST MK48T87B-24 - TIMEKEEPER chip

Post by francouai » Wed Nov 14, 2018 2:21 pm

Just coming to give you some update.

I bought another NVRAM chip (DALLAS) on a Polish online webpage for 22euros delivered.
I just removed the old Ebay Chines chip to install the new one and the falcon is holding the TIME/DATE/keyboard layout now.

This Chines guy F.K me by selling dead/crap chip. :evil:

I'm all done!
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Re: FACLON - ST MK48T87B-24 - TIMEKEEPER chip

Post by francouai » Wed Nov 14, 2018 2:28 pm

I bought the old dead chip for 8.50euros delivered in sept. 2016.
Seller is "hkutsource"

don't buy anything from him ! :lol:
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Re: FACLON - ST MK48T87B-24 - TIMEKEEPER chip

Post by exxos » Thu Nov 15, 2018 10:59 am

While there is a lot of junk from China (wouldn't surprise me if it was faulty) ... but Falcons are temperamental with the RTC... you could have a batch of 10, and half won't work.. There is a huge thread on this, but I don't have time to look into it.

You could have always go one from my store...
https://www.exxoshost.co.uk/atari/last/storenew/#0089
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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