VOGONS


First post, by CapitanOdessa

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Hello! I hope you're good!

I have a PCChips M560 Rev.3.1A I want to restore, and make it usable without the worry that it might just blow one of these days. I bought it pretty cheap, about 2 US dollars in my currency, and I was pretty surprised when I managed to boot it up and get into the BIOS. I didn't test it throughly, mostly because I was scared the whole time it could break or something, it had been stored inside a box for quite a long time, at least that's what the vendor said.

The point is, it has a socket, and a battery that's dead, the type that is inside those modules with clock and everything. I want to replace it, but I found only one guy that sold this type of thing, and it doesn't look quite the same. Instead of VIA, it is a DALLAS, and since it is quite expensive, I'd rather ask here instead of just buying something that could end up being useless. Sorry for quality of the pictures, my phone is a potato.

Upside down Motherboard
OV1enLB.jpg?2

Close up to the module
6c8gebt.jpg?1

The socket (Yay! I won't have to desolder it!)
kWDerFw.jpg?1

What I would be buying
Z2zDLs1.jpg

The location of the module is quite awful, it takes some space for PCI cards. Anyway, what do you guys think? I got to read the specs, but I will be honest, I don't understand much of it and the diagrams I found, both had different words on some pins. I was also planning on recapping the whole thing, but I'll probably make a post once I have the tools to do so...

Thanks in advance!

Reply 1 of 8, by maxtherabbit

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the dallas part is just fine, I reviewed both datasheets

just make sure to buy it new from a reputable supplier like digikey or mouser

From the Via datasheet:

The VT82887 Real Time Clock is designed tobe a direct replacement for the DS12887. TheVT82887 is identical in form, fit and functionto the DS12887.

Reply 2 of 8, by Scandy

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Hello and pardon me if I write here.
I have a maiboard with the same (socketed) RTC clock. It was exaust so I removed it but now the system (that was fully functional after F1 at boot) now doesn't POST anymore! 😱😭
Is this normal? Thanks

THE NIGHTLAND is my board + video game for Commodore 64.

Reply 3 of 8, by TheMobRules

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Usually motherboards will not POST without an RTC chip. If you want to use the board you should put the RTC back in, even if the battery is dead. The RTC will be powered while the computer is on, so it should work, of course you will need to fit a new battery if you want to keep the settings/time after turning off the PC.

Reply 5 of 8, by iraklis777

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Dallas rtc maybe is not compatible with this via rtc. On my motherboard at least it is not...
I have A soyo 5va2 socket 7 motherboard , and i recently replace my dead via rtc with the dallas one.
Bios keeps reseting to default again and again with bios checksum error message and battery failed message.

Reply 6 of 8, by mkarcher

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iraklis777 wrote on 2021-05-27, 20:18:

Dallas rtc maybe is not compatible with this via rtc. On my motherboard at least it is not...
I have A soyo 5va2 socket 7 motherboard , and i recently replace my dead via rtc with the dallas one.
Bios keeps reseting to default again and again with bios checksum error message and battery failed message.

This is a known issue that can arise if you replace a Dallas 12C887 (or VT82887) with a Dallas 12C887A (note the extra "A" at the end of the chip name). The "A" variant has a "clear CMOS" input, and if that input is active, it causes the BIOS to complain about lost setting on every reboot. Some boards designed for the non-A variant (that has no pin in that position) have this pin grounded in the socket, which causes the CMOS clearing.