(Topic ID: 287280)

NVRAM Help - Did I kill my machine trying to install NVRAM?

By pinlink

8 months ago


Topic Heartbeat

Topic Stats

  • 31 posts
  • 9 Pinsiders participating
  • Latest reply 8 months ago by CrazyLevi
  • Topic is favorited by 3 Pinsiders

You

Linked Games

No games have been linked to this topic.

    Topic Gallery

    View topic image gallery

    B9E3C621-BFA7-41F3-8EE6-2F0BD8126885 (resized).jpeg
    20200323_205406 (resized).jpg
    20200323_195125 (resized).jpg
    2B0EA020-C074-40E8-82A9-6796137988E1 (resized).jpeg
    9DD1038E-E18C-486E-B851-ACCB50DC4390 (resized).jpeg
    IMG_2712 (resized).jpg
    IMG_2710 (resized).PNG
    IMG_2708 (resized).jpg
    IMG_2694 (resized).jpg
    EC7746D9-451A-4D59-8E16-3040B525890B (resized).jpeg
    66A10203-2693-48E3-BD37-9AC94F000D81 (resized).jpeg
    A0ABBD09-2C07-4102-9AD1-5E78775395C6 (resized).jpeg
    51DA42B0-62C1-4D71-AA24-16537A43F780 (resized).jpeg

    #1 8 months ago

    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.

    #2 8 months ago

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

    #3 8 months ago

    Did you accidently install the NVRAM in the wrong direction?

    Did you set the W5/W6 jumpers correctly?

    Is there a problem with the socket, a bridged solder joint, or some other PCB issue? Can you post photos?

    #4 8 months ago
    Quoted from ForceFlow:

    Did you accidently install the NVRAM in the wrong direction?

    Looks fine.

    Quoted from ForceFlow:

    Did you set the W5/W6 jumpers correctly?

    W5 is correct for 6116 NVRAM

    Quoted from ForceFlow:

    Is there a problem with the socket, a bridged solder joint, or some other PCB issue? Can you post photos?

    Was the socket already in place? And all you did was install the NVRAM?

    #5 8 months ago
    Quoted from ForceFlow:

    Was the socket already in place? And all you did was install the NVRAM?

    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.

    #6 8 months ago

    .

    #7 8 months ago

    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.

    #8 8 months ago

    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?

    #9 8 months ago
    Quoted from pinlink:

    do I need to install a battery pack???

    No. Sometimes there just happen to be coincidences.

    U25 now may be a suspect failure now. Can you reseat your U26 and U27 ROMs?
    Also, next to test 5volts on the MPU. Can you measure at TP2, which is between U21 and U21 sound ROMs on the right side.

    #10 8 months ago
    Quoted from PinballManiac40:

    No. Sometimes there just happen to be coincidences.
    U25 now may be a suspect failure now. Can you reseat your U26 and U27 ROMs?
    Also, next to test 5volts on the MPU. Can you measure at TP2, which is between U21 and U21 sound ROMs on the right side.

    Thanks. Ok reseated the roms but no change

    TP2 measures 4.9

    #11 8 months ago

    Replacing the U25 IC socket would be my next step.

    #12 8 months ago

    Whatever happened can be fixed. There is plenty of help available here to get it resolved.

    The NVRAM modules and similar plug in modules mostly use machine pin headers. Those are typically a bit larger than the pins of the chip you pulled out. Once you plug in that module it can stretch the contacts in the socket. From that point on it is fine for any other module or device that has those same machine contacts. However going back to a regular IC can be problematic since the socket may not make a reliable contact to a regular DIP anymore. In that case the socket would need to be replaced. It’s also possible that some of the contacts in that old DIP socket were just a bit brittle and one broke so it doesn’t contact either device. I’ve seen it happen. Although unlikely you could have a bad NVRAM module. Haven’t run into one yet but it’s possible.

    I’ve put NVRAM in most my games. Just installed a similar 6116 module in my Bad Cats. Had to unsolder the RAM and install a socket in the board first. Have another for Pinbot which already has a socket so will just plug in. Haven’t popped that in yet.

    #13 8 months ago

    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
    #14 8 months ago

    It looks like the socket on your board is original. Some system 11 boards had the 6116 in a socket and some were just soldered directly to the board.

    #15 8 months ago
    Quoted from pinlink:

    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[quoted image]

    Your picture isn't high resolution enough for my old eyes but you may have just cracked a cold solder joint when replacing the chip. Carefully reflow all the solder joints on that socket with some liquid flux or add a tiny bit of new solder and closely inspect the ones for the ROMs too, reflow any that look suspect. You could also do a continuity test from each pin of the socket (with the chip removed) to the cpu / other chips it connects to.

    #16 8 months ago

    Replacing the socket isn’t bad as long as you have the proper tools and are familiar with board work. If not that’s ok but see if you can find someone local that does. The right tools and techniques make the difference between an easy smooth repair or causing more issues since too much heat can lift pads and not removing solder properly can end up pulling out the through hole plating.

    #17 8 months ago

    Pinwiki claims that surface mount nvram (of which the pinitech version definitely is... pretty obviously!) doesn't have issues with diode D1 causing too much voltage drop for the nvram to 'unlock'. You can put the NVram back in and jumper around diode D1 temporarily and see if it fixes the nvram issue.

    I'm with everyone else who said the socket may have gotten damaged with the machine pins, I really don't care for the round machine pins on the nvram, unless they're going into a machine pin socket. (I prefer dual-wipe style sockets as original).

    Any behavior observed (random flashers, etc.) is not going to tell you anything specific other than that the ram isn't working correctly. It's going to be random behavior. Ram has to have all its address and data lines correct or it's just not going to work correctly. The ram in system 11 not only stores the audits and adjustments but it's also the main system ram.

    #18 8 months ago
    Quoted from slochar:

    Pinwiki claims that surface mount nvram (of which the pinitech version definitely is... pretty obviously!) doesn't have issues with diode D1 causing too much voltage drop for the nvram to 'unlock'. You can put the NVram back in and jumper around diode D1 temporarily and see if it fixes the nvram issue.

    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..?

    #19 8 months ago

    I never had an issue with a diode making the NVRAM not boot up. If you measure the diode to be in spec, there would be no reason to replace it.

    The problem mentioned about the socket, would be in the top side of the IC socket where the pins would be in contact with the RAM/NVRAM. The round pins on the NVRAM likely had pushed contacts of at least of the pins away and now not making connection. You can test this by checking continuity from the back side of the board U25 pin 1 solder connection to the pin 1 on the RAM/NVRAM (of whichever is installed), then pin 2, etc. This will show whether each pin is making connection in the IC socket.

    #20 8 months ago
    Quoted from PinballManiac40:

    You can test this by checking continuity from the back side of the board U25 pin 1 solder connection to the pin 1 on the RAM/NVRAM (of whichever is installed), then pin 2, etc. This will show whether each pin is making connection in the IC 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.

    #21 8 months ago

    Also tried jumping diode 1, no change in behavior.

    #22 8 months ago

    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

    #23 8 months ago

    You have my sympathy. I installed NVRAM in a Rock several years ago and it hasn’t worked since. So annoying.

    #24 8 months ago
    Quoted from pinlink:

    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. 

    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)? 

    That board looks like the trace was damaged by a screwdriver prying a chip out of the socket. I've seen that happen on many boards where the screwriver has sharp edges and ends up resting on the board when prying up instead of the plastic socket housing.

    If a trace is severed that would explain why neither the NVRAM or old SRAM work. I don't have a similar board out to look at the traces but you should be able to pull down the schematics from IPDB for your game and reference those. From the pictures it sure appears that one trace is severed.

    A while back I bought a spare MPU for one of my other games. I bought it as non working and found bad traces from a prior repair. Attached are some photos of how I fix traces like that. I'll remove the sockets, clean that area, and make new traces on the top of the board. When done it is like it never happened.

    Putting a jumper on the back will also get the job done.

    I hate batteries on MPU boards. Seen WAY too many boards messed up by battery damage. The only exception I make is for the coin cells which don't seem to leak like that. I put NVRAM in my own games and most are already done. Going to do a Volcano and my Pinbot next. NVRAM works really well and that usually isn't the issue. If there are problems it is with the work getting to that point. In some cases a bad DIP socket, and in others messed up traces and pads. Things happen but they can all be fixed.

    20200323_195125 (resized).jpg20200323_205406 (resized).jpg
    #25 8 months ago

    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

    #26 8 months ago
    Quoted from pinlink:

    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.
    [quoted image]

    Yes. That should do it. If you pull up the chip pinouts for both the 6116 SRAM and the EPROM chips that like is for data bit 2. That should be common across those chips. If one is open then nothing will work right.

    #27 8 months ago

    Just make sure that the area with the broken trace doesn't have any flecks of solder bridging across to another pad/via and you should be good.

    #28 8 months ago

    FIXED! Thanks everyone for your help.

    #29 8 months ago

    Aren't the RN sockets in these pics just like the old Scanbe sockets that are so prone to failure? If so, will the fix last long?

    -Rob
    -visit https://www.kahr.us to get my daughterboard that helps fix WPC pinball resets or my Pinball 2000 H+V Video Sync Combiner kit

    #30 8 months ago
    Quoted from rkahr:

    Aren't the RN sockets in these pics just like the old Scanbe sockets that are so prone to failure? If so, will the fix last long?
    -Rob
    -visit https://www.kahr.us to get my daughterboard that helps fix WPC pinball resets or my Pinball 2000 H+V Video Sync Combiner kit

    Nothing is as bad as the Scanbe sockets. The RN sockets aren’t fantastic but if they have a good grip on the machine pins of that module he should be fine.

    #31 8 months ago
    Quoted from pinlink:

    FIXED! Thanks everyone for your help.

    Ain’t it a thrill when you throw the switch and the game actually works?

    Hey there! Got a moment?

    Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside