NXT3.2 nvram battery low errors are driving me crazy! Need a savior. :)

[sccarlso]

I think I need an act of god to resolve this screwy behavior with nvram batteries reporting low in my NXT3.2 cpu!

It's been driving me crazy for 48 hours now as it should be simple, but it just makes no sense.  But with either nvram battery reporting low, I can't play the game even though I got lucky once, and got it loaded with only one nvram battery reporting as low, as it won't allow it to be played with either battery reporting low.  There's no components that appear to be loose or anything else that I can think of which would cause this behavior.

I've searched all over the boards, most issues were with NXT2's, and were fairly easy to resolve.

Perhaps someone has experienced the same issue I'm having on my NXT3.2 cpu might have a suggestion, or be aware of something odd I need to do or check on an NXT3.2 cpu that one wouldn't normally check, or only applies to this CPU.


Here's my situation.   

Given:  Flawless BB2E cabinet with an NXT2 CPU and working emotive light controller.  Never a battery low condition, zero hardware issues whatsoever.

Bought a refurbished NXT3.2 CPU with the required power cable to do the CPU upgrade.  Very easy to do, removed the NXT2 CPU, added the necessary power cable for the NXT3.2, reconnected everyting.  And replaced the top monitor VGA cable with a DVI cable which is required.  Used an NCLR-000-4011 clear card, booted with no errors and it cleared the nvram and backplane without any errors of issues at all.  Both monitors come up clear and perfect.

But when putting in my game dongle, OS CF, and game CF.  The nvram is corrupt so it won't install.   

Ok, gotcha.  NVRAM battery is low.  If both are, even if you clear NVRAM, when you power off, both NVRAM banks lose power and becomes corrupt with no way to recover itself. 

To verify this, I used one of the v17.00 OS CF's by itself, which has the friendly option to do an NVRAM clear on boot, so it clears, then installs the OS without powering off.  So it can actually load and display the faults it sees.  Otherwise, a normal clear card clears, but when you power off, both nvram banks get corrupt and my game won't load.   So used a v17.00 OS card to at least get some data.  It does load up after having it do a clear before continuing to install.  Once it does and I get to the setup screen, just the basic one as I didn't load a game.  Error was nvram battery 1 low.   Meh.

Ok, so got ten brand new duracell CR2450 batteries with an expiration of 2033.  But I still tested them and they read 3.2v, good.   Only thing I really hate is the battery holders in the NXT3.2 is the WORST!  Why couldn't they use normal ones so the contacts aren't so easy to get messed up!  Instead they make contact on the sides of the battery.  But, it does make it so the battery only will slide in with the correct polarity.  Negative of the battery is facing up when the CPU is installed in the machine, it won't fit right at all if it's put in backwards.

Replaced both batteries, and the only notable thing was when installed, if I test with a meter by touching the top/bottom of each battery.  Each battery now only shows 3.0v.  Ok, well, still "in range" I guess.  I would think the voltage would be the same when installed, so "something" is pulling a little current when they're installed.  Repeated booting with the v17.00 OS card with clear/format NVRAM an option while booting.   Did so, and after the OS loads, then it reported BOTH battery 1 and 2 are low!  What???   Batteries were tested good, even when in the machine.   So I cleaned the contacts, and spun them a little in the holders, and even did a voltage check on each individual battery pos and neg.  And also by touching on the pos of battery 1 and the neg of battery 2 to ensure both are making contact.  3.1v on both individual batteries and across them from pos of battery 1 and neg of battery 2.

Repeated boot/clear, now only battery 1 reports low?  What???   Shut down and removed/rechecked both batteries making contact good. Repeat the boot/clear, now both battery 1 and 2 report low again!  Argh!

As far as I know those are the only two batteries in the whole cabinet.  And a report of NVRAM batteries low would only be for batteries in the CPU itself.

I've done everything possible to seat/test the batteries in those junk holders.  Now it's finally back to only reporting NVRAM battery 1 low.  But nothing I do can get battery 1 to not show as low!  I've replaced it with many other batteries, also tested at 3.2v before installing, and testing once installed.  Still continues to report battery 1 low.  This thing is possessed! 

Anyone know of a secret to this mystery, or have any suggestions for what contacts I should use to check voltage/continuity on that would verify BOTH the batteries are making proper contact and voltage is good before loading up?  Why it flipped from both showing low after battery replacement, then only battery 1 showing low I have no idea.  I thought they were in parallel, but apparently it can still tell if just one battery is seen low.  Is there a way I can jumper it with alligator test leads so for example one battery will keep both NVRAM banks alive (for a temp solution) so it at least fools it so it sees both battery 1 and 2 with proper voltage?  Just to get a game to play without it detecting either battery slot as low for the moment?

I know the NVRAM and SSD are good and have no faults as nvram will format and return "nvram is ok" and the SSD formats and loads just fine when using the v17.00 OS CF.   If the nvram has at least 1 battery showing ok, it fixes the other nvram bank and will still load.  However while it will load, it still won't play if either battery is detected low.  Wish there was a way to acknowlege that error condition and allow the game to play anyway!  I saw a post where Rick fixed a BB2 box for a member who just couldn't get the batteries to report ok that had a loose card, but it has different battery holders and I believe only one removable card on an NXT3.2 CPU which is seated well.  Also it can be easy to reverse polarity on a NXT2 CPU, but not on an NXT3.2 as they only fit the battery carrier in the correct way.  I checked but can't find anything loose on the CPU board or any components at all.  Plus everything functions and reports ok.  No hardware errors other than when the nvram is corrupt from power loss.

Only "odd" thing I noticed that could just be due to design.  Is if I meter from pos on batt 1 to neg on batt 2, I get proper voltage.  But!  If I test the other way, from pos on batt 2 to neg on batt 1, I get very little voltage.  Thinking it could just be due to a diode in the circuit or something, one would usually see the same voltage testing in either direction but not always the case.  If that's abnormal, what would cause that?  Just mentioning that one observation that I can't explain in case that might point to a cause here.
 
I'd love to solve this, mainly so if it ever happens again I'll know what to test and ensure it's good voltage and connectivity on the batteries.  If I figure this silliness out, when I need to replace them again I won't be driven so crazy!  lol

Any and all suggestions welcome!  Even if it sounds silly, I'll test it!  I'll even put a bug bounty on this!  $25 Paypal for beers or a meal to anyone who can ultimately advise what to test that gets this fixed, or even can provide a way that at least gets it to play without nvram bettery errors as a temp fix. 

This one has me just stumped as the behavior makes no sense.  Hopefully it might make sense to someone that knows the circuit, or has experienced an issue like this before and fixed it.   

Thanks in advance!  Couldn't get by without the knowledge & experience of all the great NLG members!   

[sccarlso]

Well it works, kinda.

After all that time, I finally just put two CR2032 batteries in holders with leads.  Soldered alligator clips to the ends, and just removed the batteries and clipped the CR2032 holder alligator clips to the battery contacts on the battery holders.  No more battery low errors!   Bad battery holder design.  No way to reorient the batteries to make proper contact with the batteries themselves!  No bent pins of anything.  They just don't make proper contact.

It's not pretty, but it keeps the NVRAM alive for now.   What a pain.

Now yet another issue.  But new topic.  Hopefully that has a solution as well.