Zoo keeper owners - memory error on startup

barakawins

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Zoo keeper owners - memory error on startup (Fixed)

ok.... Been working on this zoo keeper. Almost there. I get this memory error upside down on startup. I got rid of the battery and installed a 3volt lithium battery with a blocking diode. Still get the same error message on startup. Is the 3volt lithium enough to get the game to come up? Am I missing something? There are two HM334 rams that are associated with this. Just looking for input. Hopefully someone can chime in here.
 
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That is usually a battery issue. I replaced my battery and it was fine then a couple weeks later it reverted back to this. There is a small jumper next to the battery that enables the board to "see" the battery. Mine was corroded do I cleaned it up and it's been fine ever since. Check yours out and see what happens. - Barry
 
jumper

I installed new pins for the jumper and for some reason, it's not working right. Does your error show upside down on the screen? Like memory error call for service? Also, when looking at the main board, the + is to the left and the minus is to the right for the battery terminals right?
 
battery

Yes, normally 3.6v nicad battery installed. I installed a blocking diode to prevent charging of the 3.0v lithium battery. I'm starting to wonder of the 3.0v lithium battery may be the problem and if it needs 3.6v on there. Doesn't seem like it should need 3.6v. Is there a place to test the battery voltage at the rams?
 
Is your coin door shut? If the memory interlock switch inside the coin door is not engaged I think it will clear memory on boot. Either be sure you're coin door is shut, or open it up and pull the interlock switch by hand.
 
memory clear

I did pull the interlock switch but I keep getting that memory error every time I turn the machine on/off. I'm starting to wonder if 3.0v lithium is enough to power the ram at U85 which saves the settings.. Hmm. I think I'll swap the ram out first to see what results I get and then I may have to up the battery voltage to see what happens. Strange though. The memory failure message screen is upside down. I'm not sure if this is normal or not.
 
Yeah. I've got one of Rip's lithiums installed on my zookeeper and it works fine.

Have you measured the voltage across the - and + on your board? I think mine is measuring at only like 2.6 and it's been working for awhile now.

Got pics of the installation?

EDIT: My memory message is upside down too after a memory clear.
 
Fixed Memory Error!!!!!

Ok.. It wasn't the battery, it was the connection!

Here's the fix.. The original battery leaked and deteriorated some of the pads on the
left (+ side) and right (- side). The W1 2 prong jumper next to the battery needed to be replaced with two new pins.

Things you need 2 convert to cr2032 lithium battery cell.

1. Lithium battery holder (usually 25 cents or under)
2. cr2032 power cell
3. Two strands of hook up wire.
4. 1 x 1n4001, 4002, 4003 or 4004 diode
5. bus wire

Here's what to do. Looking at the main board straight on, you'll see the old battery.
If your pads were deteriorated by acid, this fix is for you.

Take the lithium battery holder and take a small strand of hook up wire and solder a piece to the + side of the holder. Strip a piece of wire from the other side and install a 1n4001 diode. Band should be directed away from the holder so it doesn't charge. Then hook up a piece of hook up wire to the - side of the holder. Strip a piece away from the other side of the wire and now you're ready to solder in the + and - sides to their appropriate places on the board.

One step you must do to make sure your battery will work. Using your meter, set it to continuity test. Take the black lead and place it on the - side of the hook up wire you just soldered in. Remove the W1 jumper next to the battery and place the red lead on the pin closest to the - connection point. there should be continuity. Secondly, place your black lead on the next jumper pin and the read on the ground to the bottom of the board (runs along the edge of the entire board). If continuity is reached here too, You'll have power.

My issue was this. The + and minus pads were sooo bad, I ran bus wire from the negative hook up point to the closest jumper pin and soldered the bus wire to these two points. Then, the second jumper pin I also soldered a bus wire connection to and then ran this to ground.

All works well now!

Now for the sound problem!!!!
 
Just wanted to say thanks for that last post. I had a memory error for the past several months since I built my Zoo Keeper(I had a big thread about it about 6 months ago). I couldn't figure it out since I had replaced the ram and the battery.

Turns out I never put the diode in place. I read this thread last night and ten minutes later I was done soldering the diode in place and it works with no error now. Glad I had a bunch of spare 1n4001's on hand.

I can now say my new Zoo Keeper is 100% working!
 
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