SRAM error.

[Radmaggot]

Hi. I am getting SRAM error on boot. Which is causing a “startup tests failed. Machine locked” and halting boot. From what I can tell the board is an MKV S2. I’ve pulled the Board out and looks ok but don’t know what’s what. Any help would be appreciated. Thanks.

[MrKarter77]

Post some pics of your setup and the error, will help to identify the machine and then fault find.


I think you can do a ram clear with a set chip

[Radmaggot]

Thank you that would be great. Ive attached some pics hope they help.

[MrKarter77]

http://slot-tech.com/interesting_stuff/aristocrat/MVPOperatingManual.pdf i have that which i bi believe you use a set chip to go to the clear ram function.


Could also be possible by removing the batteries but id wait for someone with some more knowledge to chime in.

[Radmaggot]

Great! thanks for that. I will look through and give it a try. I also notice a lot of corrosion around the lithium batteries but doesnt seem to be effecting it at this stage. Can these be replaced easily?

[MrKarter77]

That could be your issue, id swap them out asap.

[Radmaggot]

OK thanks ill get on to that first and see if it makes a difference. Appreciate the help.

[rokgpsman]

Great! thanks for that. I will look through and give it a try. I also notice a lot of corrosion around the lithium batteries but doesnt seem to be effecting it at this stage. Can these be replaced easily?

Looks like maybe the batteries are install in battery holders, with plastic ties to hold them in place. So replacement is easy. Just cut the plastic ties, remove batteries and replace. I'd clean up that battery leakage or whatever it is, that stuff can eventually eat thru the board traces/copper circuit pathways.

[Radmaggot]

Thanks. Hoping Jaycar has the batteries and its just a matter of a quick clean and swap.

[Radmaggot]

OK replaced the batteries and cleaned up all the connectors. Unfortunately I am still getting the SRAM error I cant see a way to reset this error so if anyone has any further information id really appreciate it.


*EDIT.
OK i think i may have found the problem. There looks to be a component blown at the end of one of what i believe to be the SRAM chips. Would anyone know if this can be fixed or this component replaced? See pic.

[rokgpsman]

Hard to see it clearly but it resembles a surface-mount capacitor. You can see similar parts nearby, in the same position next to the other ic's. Maybe you can read the markings on the nearby parts. But the board marking for a capacitor is typically "C" and a number, for this part the board marking (ref designator) is "CD38" so I'm not sure. You can see capacitors in your photo to the upper left area that have board markings with a "C74", "C14", etc and not "CD".

A lot of time an ic will have a small value bypass capacitor near it, to remove transients that might be on the power supply connection to the ic. Just part of a good design. Normally if the bypass capacitor is removed the equipment will still operate. But if the part is damaged it might be causing a problem by being shorted, you could try to remove the remaining parts and see if that gets rid of the SRAM error. Someone with soldering skills can help with that.

I don't know if that's what this broken part is, I'm not familiar with your memory board. Does it look broken, or does it look burned, like it shorted or got hot? If the board has a part number perhaps you can get one from a place that sells Aristocrat parts?

[Radmaggot]

Thansks rokgpsman. Going to take it in to a local circuit board guy today and see what he can do. My soldering skills aren’t too bad but don’t mind paying if someone can do it better than me.

[Heihachi_73]

CD38 is a capacitor, it's probably prefixed "CD" on the board due to being tied to the nearby chips, it's still numbered in the capacitor range (e.g. C35 is near the heat sink of the top middle mosfet/voltage regulator, C39 is just above the chip with the blown CD38 cap, and I can't find any other capacitor numbered in the 36/37/38 range). If you have a way of measuring capacitance, check the values of CD37 and CD36 to make sure you have the right replacement (note that an ESR meter like the ESR70 won't show capacitance below 1µF as it is designed specifically for electrolytic caps).

Going by the three batteries, is this a Queensland or Victorian machine? A NSW MK5 usually only has 1 battery. If the EPROMs aren't NSW versions (or non-USA overseas chips) they will most likely not be usable without having the external comms (QCOM or VLC) hooked up e.g. it will say GAME DISABLED on screen and not take coins or anything.

[dave2228]

Hey mate I’ll be able to help u inbox me

[Radmaggot]

Thanks for the help. Unfortunately I don’t have an instrument to measure capacitance. It’s a QLD machine I believe, does his mean it’s useless? I thought because of the age it may. It have had those features to disable it. What other options do I have for it? How hard is it to do a MAME install?

[Radmaggot]

Hey mate I’ll be able to help u inbox me

Have pm’d you

[Heihachi_73]

You should be able to convert it to a NSW machine by adding a LAB comms board and swapping the EPROMs with NSW versions - AFAIK NSW games don't care about the extra batteries. Without a way to hook up or fake the comms a Queensland game will never run by itself. There used to be an ancient DOS (or Win9x?) program which emulated the QCOM protocol but it's probably impossible to find these days, and if it needed a serial or parallel port you would need an equally ancient PC to run it too.

[Radmaggot]

Yeah thanks. I think ill try just get another board and replace the one thats in it or just put it back in storage.