Xbox:RAM Upgrade

This process is dangerous and can cause permanent damage to your Xbox motherboard if you do not have advanced soldering skills. Proceed with caution.

On version 1.0-1.5 Xboxes, there are empty spots that RAM chips can be soldered onto. With the right software, you can take advantage of this extra RAM to play three of the Sega Chihiro (Xbox-based arcade board) games, run emulators with better compatibility and performance, and tweak some games via XBE patches to run with better performance. Version 1.6 Xboxes do not have the extra sockets, and so can not have extra RAM added.

This guide is for the "drag soldering" method of installing RAM chips. While some recommend a method with a heat gun, it is easier to mess up your installation or accidentally overheat nearby capacitors with a heat gun.

• Note that kernels 3944, 4034, 4817, and 5838 will not boot with the stock BIOS if the RAM has been upgraded. You will need to use a custom BIOS that supports 128MB of RAM on the TSOP or modchip.

Required Items

You will need:

• Great confidence in your soldering skill - this is not a job for the inexperienced
• A soldering iron, preferably a hoof or chisel tip
• Non-corrosive and non-conductive flux, preferably liquid like Kester 959T
• Solder, preferably leaded
• Desoldering wick or solder braid, preferably with rosin/flux
• Isopropyl alcohol (IPA), preferably 90%+
• Cotton swabs
• (optional) Electrical tape
• (optional) A brass wool tip cleaner
• (optional but highly recommended) A multimeter
• (optional but highly recommended) A soft bristle toothbrush
• (optional but highly recommended) A microscope or stationary magnifying glass and good lighting

Choosing RAM

Any type of Samsung RAM can be mixed and matched on an Xbox motherboard, you will need 4 chips in total.

• Samsung K4D263238F-UC50 - Newer and less power draw than D variant, lead free
• Samsung K4D263238F-QC50 - Newer and less power draw than D variant
• Samsung K4D263238D-QC50 - Newer and less power draw than M variant
• Samsung K4D263238M-QC50 - Base version of RAM
  • -QC40 /-UC40 can be used, the difference being that they can be clocked slightly faster.

On a 1.6b Xbox, you must use Hynix RAM. You can use Hynix RAM on a non-1.6b ONLY if you swap the existing RAM modules so that they are all Hynix.

Some sellers online sell knock-off "Samaung" RAM. Reportedly, these can work, but have a higher chance of being dead on arrival.

Installing RAM

1. Disassemble your Xbox down to the motherboard. Observe the empty pads and check if they are pre-filled with solder. Earlier motherboards (1.0/1.1) generally have the pads pre-filled so you will not need to add any solder, but it is much harder to align the RAM chip pins on the pads if they are pre-filled, so if you have difficulty aligning the chips you can remove the solder with desoldering braid, taking care to line the braid up along the pins to avoid ripping nearby pads. As a tip, you may also find it easier to start with the two RAM chips on the bottom of the motherboard, as there are less components in the way.
2. Swab the empty pads and the area within and around them with alcohol to get rid of any dust contaminants.
3. Place the first RAM chip onto the board. Ensure that the orientation is correct by checking that the slightly indented circle on the top of the RAM chip is on the corner closest to the white circle printed on the motherboard.
4. Line up the pins of the RAM to their pads, checking each side to make sure you are not overlapping pins and pads incorrectly. It's recommended to put a small piece of electrical tape hanging off of one side of the chip, and your finger on top of the chip so that when it is perfectly aligned, you can drop the tape down to hold it in place and make small adjustments if needed. Once it is in place, tack down one corner pin. You can make very small adjustments, taking care not to bend the pin too much, and tack down the opposite corner pin.
5. Choose a side of the RAM chip and squirt flux all over them. It's no worry if you flood the board with flux, as you are using non-corrosive / non-conductive flux. If your pads were not pre-filled with solder, add some solder to your tip. Drag your solder iron slowly across the pins from one end to the other. As you drag, you should see each pin / pad get covered with solder. You will likely create a few bridges, so go over it again to see if they will work themselves out. If not, remove the bridge using desoldering braid, taking care to line the braid along the pin to avoid ripping up nearby pads. Go over the pins a final time by holding the iron momentarily against the corner formed by the pin and pad to heat both simultaneously, without dragging the iron between each pin. Repeat this for each side of the chip and thoroughly check for bridges between the pads, the long parts of the pins, and the top parts of the pins. You may need to use alcohol and a toothbrush to gently clean up the pins to check for bridges.
6. Once you are confident the RAM chip is correctly attached, use alcohol and a toothbrush to gently clean up the pins. Allow the alcohol to completely dry off. Alcohol will have soaked under the chip itself, so allow it a good 15 minutes to dry or blow the alcohol out from under the chip using compressed air to expedite the process.
7. Plug the power supply, fan, controller cables, hard drive, DVD drive, video cable, power cable, and a controller back into the Xbox and power it on. If it successfully boots up to XBlast, proceed to the next step. If the Xbox reboots infinitely or reboots three times then shows flashing red and green (FRAG), check back over your soldering, paying extra attention to the pins that carry power on the RAM pinout (any pin starting with a V).
8. Navigate to Settings > Tools > 128MB RAM Test. This will check each of the four extra RAM chips and report Failed or Success for RAM chips 1, 2, 3, and 4. You should receive a Success for the RAM chip you just completed. If you did not, you likely either have a bridge or a pin is not properly connected to the pad (likely an address or data pin). If you have a multimeter, it may help to test the tip of the pad and the top of the pin for continuity.
   • If you plugged in your controller after powering on the Xbox and cannot navigate, try rebooting the console.
9. Repeat steps 2-8 for each of the other empty RAM pads, checking each RAM chip one by one. Once they are all reading as Success, you can flash your desired BIOS that supports 128MB of RAM.