I'm so confused. I just installed NVRAM onto my system 11 game. Used 6116 just like the site says to. When I got it installed and turned the game on, the game started freaking out (Flahers were going off, F4 fuse on the driver board blows, and just flashes "U25 Ram Failure" on the display). so I quickly turned it off.

So I then re-installed the original RAM just to see if it would work as it was before I installed the NVRAM. Now even with the original RAM re-installed, it just flashes U25 Ram Failure. (but not "freaking out" as it does with the NVRAM installed).

Did the NVRAM break my game? Why is the game now not working even with the original RAM re-installed? The game was working perfectly before installing the NVRAM.

51DA42B0-62C1-4D71-AA24-16537A43F780 (resized).jpeg
66A10203-2693-48E3-BD37-9AC94F000D81 (resized).jpeg
A0ABBD09-2C07-4102-9AD1-5E78775395C6 (resized).jpeg

Yes, and it was working before I installed the NVRAM. Only "issue" is that there was no battery holder so it would never hold settings/highscores/etc. and I had to go through the menu everytime I powered the game on. This is why I ordered the NVRAM.

.

ok, I am now convinced that I installed the NVRAM correctly. The jumpers are correct, it was installed the correct way, etc.

So why did this break my game? Any ideas on what the solution is here? I mean, do I need to install a battery pack??? I really thought the NVRAM was going to fix all my issues, turns out it made them a lot worse, now I can't even play the game.

Any ideas on what to look at here? why installing NVRAM would cause the flashers to all flash quickly and cause F4 To blow? And shouldn't NVRAM fix any U25 RAM errors?

Thanks. Ok reseated the roms but no change

TP2 measures 4.9

Thanks for the help so far. The socket looks like it was installed perfectly but what you're saying makes sense I guess. I'm still not understanding why the NVRAM doesn't work in the game. I guess it could be the socket...

Now I'm not sure which ram to install once I replace the socket. The NVRAM worries me that the same thing will happen again. Here is a pic of the current socket

EC7746D9-451A-4D59-8E16-3040B525890B (resized).jpeg

Hmm, I see that now on pinwiki:

"It has been documented that some variants of DIP NVRAM may need to have diode D1 replaced with a jumper or jumped around the diode, in order for the game to boot successfully. D1, a 1n5817 diode, has a very low forward voltage drop (about 0.2 volts) vs. the normal 0.4-0.6 volts most other diodes have. If replacing U25 with the memory RAM, some memory RAM will not unlock and allow writes until the voltage is 4.8 volts or so. The 1n5817 D1 diode is just enough to prevent some memory RAMs from allowing writes. To solve this, solder a jumper wire around the D1 terminals, or remove D1 entirely and replace with a jumper. Surface mounted NVRAM on an adapter board is not susceptible to this problem."

Perhaps I should try this before replacing the socket..?

Nice! Ok, I just did this test and can confirm there is continuity from the NVRAM pins to the back side of the board solder points....so... The socket is good I think.

Also tried jumping diode 1, no change in behavior.

ok guys, I think I may be on to something here (at least I hope so). 

If you look at where the U25 socket is installed there are 7 solder points underneath where the RAM sits. It appears that one of these solder points (indicated by the red arrow in pic below), may have a broken trace. 
IMG_2694 (resized).jpg
9DD1038E-E18C-486E-B851-ACCB50DC4390 (resized).jpeg
I have tested continuity on all 7 of these solder points to legs of the U26 Ram, and the only one I can not find continuity for is the one pictured above. 

Can someone please tell me if there should be continuity between these two points in the picture? If so, Could I just add a jumper to these points (indicated in blue)? 
2B0EA020-C074-40E8-82A9-6796137988E1 (resized).jpeg
IMG_2708 (resized).jpg
IMG_2710 (resized).PNG
IMG_2712 (resized).jpg

Ok I tested for continuity between these two chips/legs and these are my results. Blue is continuity, red is none. So that has to be my problem right? Just want to confirm before I add a jumper and put it back in the game to test.
B9E3C621-BFA7-41F3-8EE6-2F0BD8126885 (resized).jpeg

FIXED! Thanks everyone for your help.