That bad taste you feel when erasing eproms might be from the UVC creating ozone. Being close to an ozone creatiing device can be smelled and sometimes even tasted.
Great video Glen =D My guess is the RTC chip is the issue, but it still could be that HC32! You can sometimes see evidence of the OR gates working fine with a logic probe, but processing is so fast you dont always see evidence of where its not working (inverse logic where condition is not met). For example where its pulsing!
Thanks Chris. At least with unibios I can use the system again. Wouldn't be hard to swap out the HC32, I've got a few scrap boards about so if I can find a spare chip on one I may just swap it and see if it changes anything.
Are you sure it's not one of those static RAM chips are OK? Given that resetting the NVRAM cleared the issue until you tried writing it could be the NVRAM. You could always try putting a CR2032 socket and battery in there in case that's confusing things. That's the simplest things to do.
I haven't found any information to suggest a ram error here would throw the calendar error but I suppose there may be something at fault. Would explain the corruption as I entered a date. I just can't fit a CRA2032, it's a rechargeable battery so wil need to order a LR2032 but I've been reliably informed that a dead battery also won't throw the error.
Shouldn't matter when the board is powered up but yes it'd be needed to retain the calendar if powered off. I'm assured though that a dead battery itself is not the cause of this error.
Shouldn't the calendar be set to a "sensible" date and time - otherwise the BIOS senses gibberish and throws the "calendar error"? I suspect that once the battery died, losing the clock crystal signal would not have helped either, it reset the clock chip to a default value (usually year 1900) and the BIOS knows it shouldn't be that - hence the "calendar error". Old PC motherboards did similar when the date and time wasn't set and the read time was too far in the past (1900/1/1) or future (2100/1/1)? When you get a new battery don't forget to reset the date and time or you might/will get the error again I expect.
Instead of just printing a case, build a bartop cabinet to put it in, with proper arcade buttons / stick (if you can hack a way to use said buttons/stick instead of the Saturn pad?
That's not a bad idea although space for a cabinet is something of a premium. If I were to do it, it'd be easier to just change to a neo geo type super gun from which the individual buttons can be simply wired.
Everything you see here cost me about £150 if I remember correctly, well less the Saturn pads but for the MVS, super gun, multi cart, PSU and AV cable it was about that. I know I could just use mame but something special about running these games on the original hardware.
Never dabbled in the arcade end of things but glad the board is usable again! So sad that sources of these types of parts are getting scarce, not helped by the current crop of 'system strippers' jumping on the bandwagon for profit :(
I was sent a replacement part, put it somewhere safe and totally forgot where that is 😅. I'm sure I'll find it one day then I can have a working rtc again.
Odd that there's a pentagram below the BIOS... Is SNK putting a hex on you for removing that chip? :P And if that UV eraser is so sketch maybe just replace it already, or add some fuses and stuff, don't end up like MarkFixesStuff. The Weird taste in your mouth is probably the Ozone, that's naturally occuring when you have UV light.
Yeah I need to bin that UV light box and get something better. It's only used the odd time though and I always keep an eye on it while it's on. Not sure what the symbol on the PCB is about. Hopefully no SNK demons were released when I removed the chip
Did you see GadgetUK's video? It does say that the battvcc etc. that rail should be 5 VDC. Now he has a different board and I don't remember if the battery in near the 74HC32 the vcc was connected trough a via on your board as well. Worth checking.... th-cam.com/video/-qluF90bjgM/w-d-xo.html I wonder if when you initially bought the board the battery was suppyling the vcc to the clock and hc32 and it just drained down and that is why it has the error now. Did you see if replacing a new battery that you still get the calendar error?
Glad you got it working. Id check for damaged traces under the remaining adhesive on the back of the book keeping area.
Not a bad idea, I'll remove the rest of it and have a look.
So happy I was able to help out in some way even if it's just sending an eprom.
Thanks Lee, helped me get the machine up and running again.
That bad taste you feel when erasing eproms might be from the UVC creating ozone.
Being close to an ozone creatiing device can be smelled and sometimes even tasted.
Great video Glen =D My guess is the RTC chip is the issue, but it still could be that HC32! You can sometimes see evidence of the OR gates working fine with a logic probe, but processing is so fast you dont always see evidence of where its not working (inverse logic where condition is not met). For example where its pulsing!
Thanks Chris. At least with unibios I can use the system again. Wouldn't be hard to swap out the HC32, I've got a few scrap boards about so if I can find a spare chip on one I may just swap it and see if it changes anything.
@@CRG I may have a spare one herre on reflection (if I can find it lol) - from the MV1A that was scrapped in the (7 MVS repairs series I did).
@@GadgetUK164 that would be greatly appreciated if you did have it.
Are you sure it's not one of those static RAM chips are OK? Given that resetting the NVRAM cleared the issue until you tried writing it could be the NVRAM.
You could always try putting a CR2032 socket and battery in there in case that's confusing things. That's the simplest things to do.
I haven't found any information to suggest a ram error here would throw the calendar error but I suppose there may be something at fault. Would explain the corruption as I entered a date.
I just can't fit a CRA2032, it's a rechargeable battery so wil need to order a LR2032 but I've been reliably informed that a dead battery also won't throw the error.
Surely you need to put the battery back in in order to reset & save the corrupted calendar info?
Shouldn't matter when the board is powered up but yes it'd be needed to retain the calendar if powered off. I'm assured though that a dead battery itself is not the cause of this error.
Shouldn't the calendar be set to a "sensible" date and time - otherwise the BIOS senses gibberish and throws the "calendar error"? I suspect that once the battery died, losing the clock crystal signal would not have helped either, it reset the clock chip to a default value (usually year 1900) and the BIOS knows it shouldn't be that - hence the "calendar error". Old PC motherboards did similar when the date and time wasn't set and the read time was too far in the past (1900/1/1) or future (2100/1/1)? When you get a new battery don't forget to reset the date and time or you might/will get the error again I expect.
Happy hello everyone!
i am surprised no one has come up with a replacement for the RTC
the NEO-BUF it was two 74LS245 Chips on the same package,
I think the nvram can also save the settings of the game such as the difficulty so you don' t have to set do it each time you select a new game.
great job crg!! but neo geo....bah...amiga is the best!!!
The NEO-BUF on mv-1a (and other boards like mv1b for example) causes a lot of problems,
Instead of just printing a case, build a bartop cabinet to put it in, with proper arcade buttons / stick (if you can hack a way to use said buttons/stick instead of the Saturn pad?
That's not a bad idea although space for a cabinet is something of a premium. If I were to do it, it'd be easier to just change to a neo geo type super gun from which the individual buttons can be simply wired.
Neat. I'm too scared to get into arcade... Maybe one day when I've got more money to burn... Nice video!
Everything you see here cost me about £150 if I remember correctly, well less the Saturn pads but for the MVS, super gun, multi cart, PSU and AV cable it was about that.
I know I could just use mame but something special about running these games on the original hardware.
It's a "slippery slope." The full-size cabinets start calling. I made myself stop after 9... 🙄
Never dabbled in the arcade end of things but glad the board is usable again! So sad that sources of these types of parts are getting scarce, not helped by the current crop of 'system strippers' jumping on the bandwagon for profit :(
Did you try putting a battery back in?
Not yet, i need to get a rechargeable 2033.
@@CRG can also just add a diode to disable charging i think?
What about a MC146818 in place of that NEC RTC.
I was sent a replacement part, put it somewhere safe and totally forgot where that is 😅.
I'm sure I'll find it one day then I can have a working rtc again.
Odd that there's a pentagram below the BIOS... Is SNK putting a hex on you for removing that chip? :P
And if that UV eraser is so sketch maybe just replace it already, or add some fuses and stuff, don't end up like MarkFixesStuff. The Weird taste in your mouth is probably the Ozone, that's naturally occuring when you have UV light.
Yeah I need to bin that UV light box and get something better. It's only used the odd time though and I always keep an eye on it while it's on.
Not sure what the symbol on the PCB is about. Hopefully no SNK demons were released when I removed the chip
Did you see GadgetUK's video? It does say that the battvcc etc. that rail should be 5 VDC. Now he has a different board and I don't remember if the battery in near the 74HC32 the vcc was connected trough a via on your board as well. Worth checking.... th-cam.com/video/-qluF90bjgM/w-d-xo.html I wonder if when you initially bought the board the battery was suppyling the vcc to the clock and hc32 and it just drained down and that is why it has the error now. Did you see if replacing a new battery that you still get the calendar error?
UV light can create ozone ... You shouldn't have it so close to you when it is running.
I'm getting this error also.
Dude, make another vIdeo and fix that damn error.
If I can get another RTC chip ill maybe do a quick follow up.
@@CRG Check if static ram chip that's supposed to hold the date and time data is OK too. It well might be the culprit here and not the RTC thingy.