Full RAM swapping guide

Discussion in 'Nintendo 64' started by BitBuiltBot, Feb 9, 2016.

  1. BitBuiltBot . Site Robot

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    Credit: Sidence

    Disclaimer:


      • I am not responsible for the potential damage that you may wreak on your N64, yourself, or anything else for that matter. This guide is purely informative; understand the risks of of bodily and/or material damage implied with working with these kinds of tools and electronics in general. No warranty is provided, express or implied, so when performing this modification proceed cautiously.
    Note:
    • This guide refers to NTSC N64 motherboards both through example and by the CPU Revision number, however, this guide is compatible with all N64 motherboards manufactured before or during 1997 of any region. Only N64s manufactured before or during this date qualify because they have two spaces for RDRAM, whereas newer motherboards only have one.
    The N64 comes in multiple revisions. The most visibly apparent change is between Revisions 3-5, which had 2 2MB chips of RDRAM, and Revisions 6-9.5, which have only one 4MB chip.

    Here's a Rev 3 motherboard, which has 2 2MB chips:
    [​IMG]

    And here's a Rev 6, which has 1 4MB chip:
    [​IMG]

    The aim of the "RAM Swap" mod is to remove the 2MB chips from an N64 with a CPU revision of or lower than 5 and replace them with 4MB chips.

    Where to get 4MB chips:
    1. An official N64 expansion pak
      1. 3rd party expansion paks often have only 2 2MB chips, which will not help us for this guide
        Note: some 3rd party Expansion paks DO have a single 4MB chip, but it's a crapshoot as to whether you'll get one or not. All official paks have a 4MB chip, so make sure to get one made by Nintendo, that is, of course, unless you like to live life on the edge.
    1. A Rev 6+ N64 Motherboard
      A group buy
      • RDRAM isn't manufactured any more, or, rather, it's no longer available to the consumer market. It must be purchased in large quantities for manufacturing companies to be arsed with making it. Not just any RDRAM can be used in the N64, either; it has to pin-compatible. If you are interested in a group buy, check out ShockSlayer's thread on it. We need more interest to get the order rolling, so please post in that thread if you are interested.
    Those of you that don't get your RAM by cannibalizing older hardware will be able to skip the first step of removing the RAM.

    To remove the RAM, you'll need some tools. You have a few options:

    Heat Gun
    [​IMG]
    (Random picture I got off the web)
    I have used these in the past, but I didn't use them this time around. Set it on the highest setting, or else it won't get hot enough to melt the solder. Any cheap one will work fine as long as it can get hot enough, but make sure you're careful. Ones with large heads can easily damage surrounding components, including the RAM itself, while you're waiting for the solder to melt.

    Blow Torch
    [​IMG]
    Probably the most dangerous choice, but also the cheapest and most effective.
    Set it just about the lowest it can go before it goes out completely, but make sure that it's "blowing" enough that you still have some good flame control. This is about the size of flame I used to remove the chips:
    [​IMG]
    It's really hard to see in this picture, (it's kind of hard to capture on camera, sorry) but this isn't the entire flame; there is a fainter "halo" around the flame that is still almost as hot, and you don't want the main body of the flame or the "halo" to touch any of the components. My cheapy Harbor Freight pencil torch has a pretty significant cut off, so I couldn't get it much smaller than this without intermittent cut outs. If you've never used a blow torch before I can't really recommend you go this method, at least, not without a little bit of preparation and practice. Working with open flames can be scary, but as long as you are in a proper environment (few or no flammables around, etc) and have a steady hand then you should be fine.

    Chip Quik
    [​IMG]
    This stuff is pretty neat. It's called bismuth solder, which has a really low melting point (for solder, at least) so you can have enough time to remove surface mounted components. From Chip Quik it's a bit expensive, but if you can find some, any sort of bismuth solder will do. Remember to use a good amount of flux, and work quickly, because despite the low melting temperature the bismuth solder can cool down in place, which means you'll have to heat it up again. This video describes how to use it in full (on an N64, no less!).

    As you can see from the video, you use it almost just like solder except with a gratuitous amount of flux and your aim is to remove the component from the board rather than bond to it.

    SS's snip, bend n' clean
    This method shouldn't be done on a 4MB RAM chip because this effectively makes the RAM useless by cutting leads, but it's a really clean and easy way to remove your 2MB chips from your primary board:
    Take a razor blade and cut these two sets of pins from the back of the RAM:
    [​IMG] [​IMG]
    (You can also use tweezers or needle nosed pliers to bend the pins off as well.)
    Now grab the back of the RAM and lift it like so:
    [​IMG]
    Then wiggle it back and forth until the pins break off:
    [​IMG] [​IMG] [​IMG]
    Presto!
    Now repeat this process, and clean of the solder pads. You'll want to do this in a vertical motion, in the direction of the pads, as to not bridge any of them. You might also want to use flux; it makes the cleaning easier, but is not necessarily required.

    If you're using a heat gun or a blow torch this applies to you:

    Torching the RAM directly is a terrible idea because you have the potential to ruin the RAM. Don't do it. As a demonstration of the potential destruction you have to your components, look at this poor melted RAM:
    [​IMG]
    Pictured above: a heavily heat damaged 2MB RAM chip and an undamaged 4MB RAM chip (what you see on it is leftover thermal grease).

    The proper way to do this using a heat gun or blow torch is to heat up the opposite side of the board, which requires a bit of multitasking, as you have to heat the bottom while pulling up on the RAM on the top. If you don't want to damage the motherboard, make sure to not touch the flame to the board (if you're using a blow torch). Let the heat work on its own, otherwise you might burn the PCB. Remember, heat rises and PCBs are fairly thermally conductive, so you don't need to apply heat to the bottom as long as you may think, just enough to pop the RAM free of the board.

    Either way, you remove the RAM by applying heat and push on the RAM at the same time with a small flathead, tweezers or something else the allows you some distance so you don't burn yourself like so:
    [​IMG]
    Pictured above: where to apply heat on the bottom of the board.
    [​IMG]
    Notice the RAM begin to move away from the leads under pressure in the second image. Heat was applied at this time to move it. It's important that you do these at the same time so you can get the RAM off as soon as possible; the longer it's subjected to heat the greater potential you have of ruining it. Pull off each chip at a time. Usually the RAM will pop free if you are pulling up on it under heat. If you still have a few leads connected, don't just bend of rip it off; by doing this you run a great risk of breaking leads which is often irreparable. Instead, use a soldering iron and heat up the leads that are still connected and pull it off quickly. Otherwise run a blowtorch quickly over the affected area, or use a heat gun until it's completely free.

    If you've done everything correctly, you have an N64 motherboard with 2 bare pads for RAM and 2 4MB chips to put in place of where the old 2MB chips were.

    Carefully reposition the new RAM over the solder pads such that the leads line up with their respective pad (rather than between them). Now, use some thermally resistant, low residue tape (I used masking tape, it worked just fine) to secure the RAM to the board so it doesn't move while you're reconnecting it. (Attach it out of the way so you don't accidentally melt the tape. The sides without pins will do.)

    You can reheat the pins with a soldering iron, blowtorch or heat gun, though a soldering iron is the cleanest and least risky solution. For the blow torch I definitely recommend heating from the back of the board again to avoid damage. The same goes for the heat gun. With the soldering iron, first and foremost you will want a small, precise head, like this:
    [​IMG]
    Having too big of a head makes soldering much trickier, as you have a great potential to bridge pins. You may also want to tin your tip, but there's no reason to add any more solder beyond that. You should definitely add flux paste, however, as it helps in heat transference and makes it easier to avoid bridging leads. SS also has a good tip:
    For more information on surface mount soldering, consult this wonderfully detailed video:

    As you can see, there are many ways to do surface mount soldering; the way you choose depends on your preference and whether you have the proper tooling or not.

    Afterwards, before you boot it up you need to reinspect all of the joints. Make sure you have no bridges, bent pins, cold joints, and that your RAM wasn't offset during the reheating process. If you have any of these problems, you may be able to fix it with minimal effort, or you might have to start over the process. Point being, just make sure you don't boot up until you're confident everything looks good.

    You'll still need a jumper pak to power on your N64, and you can use an expansion pak as well, but you won't get any performance enhancements out of it (the N64 doesn't know the extra RAM is there so it's not going to use it). Trimming down the jumper pak to it's smallest possible dimensions is something I have not yet done and is something for another thread.

    Thanks to SS for his suggestions, to kibble from BH for his awesome Chip Quik video, and to Curious Inventor for his informative surface mount soldering guide.

    Changelog:
    Code:
    1/23/2013
    Guide first posted
    
    1/24/2013
    Added suggestions from SS, disclaimer, PAL notice, and cleaned up grammar. I also corrected an error where I stated that the N64 has either 2 or 4 Megabit chips; the correct value is 16 or 32 Megabits, which is 2 or 4 Megabytes, respectively.
    
    2/04/2013
    Added more tips for surface mount soldering plus a video by Curious Inventor which is very informative for general surface mount soldering and shows multiple good practices for both removing and reconnecting components.
     
    Last edited by a moderator: Apr 12, 2016
    Nold likes this.

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