DTK PTM-1000 CMOS Checksum Error \ VOGONS

DTK PTM-1000 CMOS Checksum Error

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First post, by baldcoder

Posted on 2020-07-21, 16:03

baldcoder Offline

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I have a DTK PTM-1000 286 motherboard. It was working fine, but I wanted to replace the CMOS battery because it was corroded. After replacing the battery, now I get a CMOS CHECKSUM FAILED! When I use CTRL-ALT-ESC to go into the CMOS setup, it doesn't respond to keypresses (except NumLock will toggle and I can CTRL-ALT-DEL to reboot). I can't actually change any values though.

Is there a way to clear the CMOS RAM or some other way I can recover this motherboard?

Thanks.

Reply 1 of 6, by Deksor

Posted on 2020-07-21, 17:52

Deksor Offline

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Try to boot off a floppy disk with something like gsetup.
Maybe you can initialize some parts properly so the CMOS setup doesn't crash anymore

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Reply 2 of 6, by Zup

Posted on 2020-07-21, 17:56

Zup Offline

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Have you tried to use cursors from the numeric keypad?

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Reply 3 of 6, by baldcoder

Posted on 2020-07-21, 18:03

baldcoder Offline

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I haven't tried either one, but I will and let you know the outcome. Thanks for the recommendations.

Reply 4 of 6, by baldcoder

Posted on 2020-07-21, 19:20

baldcoder Offline

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The numeric keypads don't work in the CMOS setup.

I was able to boot to a floppy and run GSETUP. The first time, I just restored defaults and made sure the floppy drive was set to 1.44 and the display was monochrome. After rebooting, I got a REAL TIME CLOCK error.

So I ran GSETUP again. When I change the time field, it also changes some of the date fields as well. e.g. I entered 0102 for the time and the time field did change to 01:02:00, however the date field changed to 00/00/102.

Is this a bad RTC/RAM chip (MC146818A)?

Thanks in advance.