WPC - CR2032 MPU install

Please, The nvram discussion should be in the nvram thread not here.
This thread is about cr2032 installations.

I think that the discussion comparing using a CR2032 versus a $6 NVRAM is relevant though - don't you?

Yep -- the Simteks are a different animal than the Ramtrons.
The Simteks actually have a static RAM bank internally that the CPU is using for reads/writes. When the Simtek detects a VCC voltage drop to a certain threshold - it automatically disables static RAM and transfers whatever is in the static RAM over into a flash memory bank. When machine is turned back on - the Simtek automatically transfers what is in the flash memory back into the static RAM.
So - the Simteks actually only write to the flash memory when the machine is being powered off.

Or CR2032 versus $2.50 nvram imported directly. Which is probably why nvram came up in this thread to begin with (and not because I posted some thoughts on endurance that I'll agree may be better left to an nvram technical discussion thread).

Really though, I think the discussion specifically on CR2032s (if it could stay on just that topic) for a sepcific manufacturer's board (ie. WPC which was the topic of this thread) would be over quick. What's there to talk about? Or after a few people show pictures of installation methods on a specific board.. what more is there?

I'll offer another thought up -- I think It'd be nice if steps to doing CR2032 installations on various manufacturer's boards *cleanly* could get documented on PINWIKI.. with pictures -- that way when new threads like this are created people can be pointed to a good resource for installing CR2032 battery holders on boards & proper direction of diodes or clean ways to do the jumper wires if that's the method they want to take. I haven't really looked at what's out there but if there's not pages for every manufacturer showing how to install CR2032's if they're versatile across most of the major pinball manufacturers, then why not get them created and start pointing people there. Or adding to them as threads like this flush out better details or pictures or methods.

Taking it a step further then, document all the alternative ways for memory retention -- from the AA alkaline or rechargeable batteries that are considered a **GET THEM OFF THE BOARD** method -- to CR2032s and lithium AAs and remote battery packs with 10ft wires to reach the coin door.. to nvram. Just document the pros/cons, risk of invasiveness -- ease of install, etc. Then immediately point these threads to those resources to mitigate the same "fanboy" type of discussions that tend to occur in these threads because what works for someone doesn't work for someone else. If something gets discussed *over and over* then a resource can be created to help others and prevent threads from getting derailed too much with "my method is better than yours" conversation. Totally just my humble opinion here. Carry on with CR2032 discussion

Actually, what you suggest would be a good addition to pinwiki. In fact, I just looked on pinwiki under WPC and there is a small section under 4.9. Which, in fact, is incorrect as far as my knowledge goes. It is suggesting the use of the simtek 12c68 but makes no mention of having to retrofit it to have the required power down capacitor and proper pull up resistors added. My guess is the author meant to refer to the Ramtron/Cypress FRAM parts or the Simtek STK16C68 which are plug and play.

I agree it would be useful to provide documentation of ALL possible alternatives to using the factory batteries and holders without necessarily referring to any particular product or pricing. Simply ball park estimates for each technology.

Looks like a hack to me, if I purchased a game with this type of battery, it would be coming off and I would change it to a nram with a much cleaner look. Or go with a remote battery holder.

No offense, but its funny to me you would find a coin battery ( which many other manufacturers have used onboard), to be a "hack" but accept a remote battery holder as not?

I too would use NVRam in every possible chance but as was mentioned, that's not really the subject of this thread

as someone mentioned there is more than one way to skin a cat or get the job done (cant remember which one was said)
as long as we get rid of the alkaline and rechargeable batteries off the board then we can all sleep easier at night.
I use cr2032 on everything but wpc and wp95.
and after reading the comments from people on here who have many wpc and wpc95 machines with the CR2032 fitted (great to hear the feedback) and my experience with a wpc95 with a CR2032 there is only a small chance of coming across a board that will kill the cr2032 in 6 months.
I assumed it was the clock in the WPC ASIC chip that was considerably shortening the life of the CR2032 in problem WPC95 board.
I will have to do some current draw tests to find out what the draw on the battery is with the clock and ram together and with the ram alone in the WPC series boards just for a matter of interest.

I'm personally really digging the idea of starting doing this for a few reasons, but I don't want to have to drill.

I think I've got a junky board I can mess around with to see what I can make work.

Honestly I'm a big fan of NVRAM, but I'm not comfortable at the moment desoldering RAM from the multilayered boards. So for me, with my current soldering skills, this is a nice mod I can do myself. Battery holders are in the scope of my ability.

The only WPC game that killed the cr2032, in my experience, was the Rottendog wpc95 i had. They used a different brand of 6264. I think it's the brand of RAM that makes the difference. I notice this on games with 5101 AMI brand RAMs. those don't work well with cr2032 either.

There are low power devices ( often labeled L or LP) and Ultra Low power Devices (often labeled LL). It may be the type of ram as opposed to the brand.

LL, ultra low power devices are specifically designed for battery back up uses. Its often the difference of using a NiCad or 3V lithium battery verse using a coin battery.

Wow - so that's great!! When are you going to get started on that?

Hi Clay,

I'm planning on doing this mod to a System 11b board.

I'm a bit confused, looking at the picture in post #15, I see the jumper across the + terminals, but it looks like both sides of the battery holder go to - terminals. Could you clarify?

Thanks

Post #15 with the pictures is self explanatory.

o-tay!

Clay is right that the picture is self explanatory if you're looking for a cookbook explanation.

If you want to know why it works, it's important to know that the 3 AA batteries are in series with traces on the board to connect them.

sys11_battery (resized).jpg

Thanks, that's kind of what I figured.....I'm out of the country, so wasn't able to look at the traces. (my 1st Williams game, other than EMs).

What about two CR2032s in parallel?
I'm thinking about this option to extend the battery time and also you can replace one while the machine is off.

Batteries and sockets are cheap anyway.

What do you think?

I've read through this thread with great interest. But it seems unclear what the expected lifespan of a CR2032 is. I am to advice a guy who would like to get rid of the AAs in a WPC89 game. But reports here of CR2032 to die within 6 months I will consider af no-go.

What is the general experience? Is it rare to see them die off that fast.

Also. This game will be equipped with new CY62256 RAM. Which is praised by the manufacture as having super low standby power consumption. And I am sure it is atleast as good as the original RAM. But, the datasheet does not mention the minimum voltage requirement (oddly enough). Any experience?

Looks like it's 2.0 volts:

CY62256_VCC_Data_Retention.png

Ah. Thanks. My free text search for "standby" was too coarse.

In terms of shelf life, I had a bunch of 15 year old N.O.S CR2032 batteries sitting on the shelf in not exactly ideal conditions.

A lot of "KTS" branded batteries went flat a long time ago. The Sonys and Panasonics still have 3 volts, so too the Toshibas but the Toshibas look stained like they've dry leaked. Also one Maxell left still reads/looks good.
I still have all the flat batteries from this stash, I should probably pull them out to get more details.

At the vfw museum we have every WPC game made (except for popeye and gilligan, yeck). And they nearly all have a 2032 coin battery. So we have a pretty good example of data points. i would say average life is about 2 years. Though a couple games kick their coin battery after one year. It's probably the brand of RAM perhaps...

I did all my Bally/Williams games about 2-3 years ago. I got some cheap CR2032 on eBay. They lasted 2-3 years. I looked at the expiration date on the ones I installed and they were expired.
This time I bought some on amazon this time. I ended up replacing all of them with the amazon ones since they were expired.
I was replacing the AA batteries every year. Now I don’t worry about them.

personally i just use the cheap 2032 batteries. i have not found the name brand versions to last any longer.

Just curious: why do the lithium batteries in Stern SAM games last so long? I bought Spider-Man new in box and have not needed to replace it.

If you are going to replace the RAM chip then you will install a socket there, so why not put in NVRAM and avoid the battery for a permanent solution?

SAM boards don't use CR2032 batteries. I think they use CR2430. I haven't needed to replace one of those yet either. Although I have to admit that I wouldn't care too much if my machine's battery were to drop in voltage enough to cause a reset to factory settings - that's an opportunity to achieve cool things all over again.

Thanks all.

Simple answer. The standby current draw is lower. Which makes sense as SAM is 15 years yonger than WPC. And Stern games do not have a real-time clock. The battery is only feeding the RAM. Whereas on WPC it also runs a corner of the ASIC and the clock generator. And I will believe they are not cheap.

Just wanted to present him his options. And he want the NVRAM. Which I am not able to supply yet.

Personally, I will not use the NVRAM. But I like the coin cell solution.

Thread revive. I did this to my Grand Lizard and it won't retain settings. I was previously using lithium AAs. Battery is good. Reads 3.3vdc. Installed just like it is in the pic of post #66. Any suggestions? Was working fine with the previous AAs.

Did you check continuity with a DMM?

you need to check with the DMM that the last pin of the ram is getting battery voltage (game off). if it's not (and trust me, it's not), you have done something wrong...

You're correct. No voltage there. I have continuity from the negative battery terminal to ground and from the positive terminal to the non banded side of D2. What could I have missed? Here's the board. Thanks.

IMG_20200801_154157876 (resized).jpg

that diode could be open. that would do it! check it with DMM set to diode function, black lead on banded side of diode, red lead on non-banded side of diode. should be .2 to .6

If you have the battery voltage (against ground) at non-banded side of D2 but none on the banded side, the diode is definitely open. Remove the battery before trying the diode check with DMM.

Also check that the battery has continuity with the holder! Some battery holders I have used tend to melt while soldering and lose contact with the battery.

I assume everything was working before you started this mod? If so, then the diode going out during the battery update process would be very odd/coincidently, but I guess not impossible. Start narrowing the problem down by successfully finding the +3v on the board first with your DMM...

It was the holder itself. Thanks guys. Even though it was locking in, it wasn't making enough contact to conduct voltage. Just tightened the positive terminal click release thing and it's working good.

I thought I read/heard somewhere that the diode on WPC MPU's can sometimes fail and start charging the battery (this is bad, obviously).

Does anyone use an extra blocking diode in place for extra insurance ?