The Definitive Wii Trimming Guide


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Jan 28, 2016
The Definitive Wii Trimming Guide


Before proceeding further, you must first determine your board revision. Please use the Revision Identification Guide.

This guide is primarily designed to be used with CPU-40 boards and higher.
If your Wii is a 6-layer board, you will require the information in this guide as well as the 6-layer expansion guide.

Neither this guide nor the 6-layer expansion supports relocating the disc drive. With the systems in RVLoader, retaining the disc drive offers no significant benefit for the difficulty involved in soldering onto 0.1mm traces next to the GPU.

Softmodding your Wii

This guide is designed to be used hand in hand with RVLoader - a softmodding setup designed specifically for trimmed motherboards. It is the only supported softmod pack on BitBuilt, and is required to be installed before trimming. Failure to do so will result in Wifi relocation being a requirement for the motherboard to boot.

Remember: anything can go wrong once the board is cut. It is vital to ensure the console is fully functional since this will establish a known working baseline condition prior to trimming. Don't be disheartened if your Wii ends up non-functional, it's a common occurrence that still happens even to the pros. There's always another chance to try again!

Designated trim

This entire guide has been designed around one specific trim. The Wii is different from the GameCube in that trimming less things off is harder to properly support as there are more issues with determining what remains connected and what doesn’t. There are also certain wiring requirements such as Bluetooth that even on larger trims require the same difficult relocation to 0.1mm traces.

Note: It is highly recommended to perform all possible relocations before trimming the board to allow easier verification of a working system. For the easiest possible troubleshooting: perform one relocation at a time and test the system once the relocation is complete, before moving onto the next relocation.

Once ready to trim, cover everything inside the red lines with masking tape, and then cut slightly outside the red line. It is safer to cut this way and then sand down the board to meet the line. Once the shape has been cut, sand the edges of the board down with at least 600 grit sandpaper to ensure the internal layers are not bridged. Be sure to remove any cut or damaged components along the edge of the trim before attempting to power on the board, or you may end up with voltage shorts that could damage the system.

The large black component that the bottom left diagonal line cuts through can be removed with no problem.

Confirming the trim works

A trimmed unsoftmodded Wii motherboard has 4 requirements in order to boot. It must have:

  • Bluetooth
  • Wifi
  • U10
  • Custom regulators

Otherwise, the console will display the infamous black screen (or no signal at all).
However, with RVLoader, this list has been reduced to two requirements:
  • U10
  • Custom regulators
With the NoWiFi cIOS installed, Wifi is no longer required, and Bluetooth is only required if you want to use wiimotes and their accessories. Thanks to the GC2Wiimote patch (included in RVLoader) you can still play Wii games without the Bluetooth module.


Bluetooth is the most difficult optional relocation on the entire board. It has a unique design in that the two required data traces(pins 10 and 11) go straight from the resistors near the plug, all the way to pads underneath the GPU without using vias. This means the only way to reconnect bluetooth properly is to scratch the solder mask off the 0.1mm traces and solder wires to the traces directly. This can be done with 30AWG wire, but using 32AWG or higher (larger number = thinner wire) solid core enameled magnet wire is recommended for these two data lines. The data lines are a differential pair and should be twisted together tightly like a helix in order to mitigate interference. For 3.3v and GND, use 28AWG or thicker stranded wire. Please do not attempt to power the bluetooth module or any other components using solid core wire.

Note: While fine pitch soldering like this is fiddly and intimidating, it is only two wires, so take your time and ask for help if you need it. It's also recommended to securely mount your bluetooth module in some way to reduce the risk of breaking the delicate solder joints or otherwise damaging the traces. Some thin double sided tape is good for this purpose, as we do not recommend using epoxy or glue. If you find this relocation too difficult, it's alright, it can be left out of your build thanks to the aforementioned GC2Wiimote patch allowing Wii games to be played without the bluetooth module connected.

Note 2: GC2Wiimote is still in development and does not currently support all motion control types. Games that use unsupported motion controls, like the "flight stick" controls and rotation controls in Mario Galaxy's Rolling Ball levels and Manta Surfing levels respectively, as well as all Wii Motion Plus titles, cannot be completed using only GC2Wiimote controls.

If these test pads are not visible on the bluetooth module in your Wii, the sticker may be covering them and should be carefully lifted to expose the pads. All modules have these test pads, so not being able to see them immediately is not a cause for panic.

U10 relocation

In order for the Wii to boot up, the GPU must receive a delayed 3.3v signal connected to the via pictured below. The delayed signal is generated by the U10 IC located near the MX chip.

The easiest method of solving this problem is by removing the U5, a convenient component with the same footprint as the U10. It is located next to the GPU and CPU and is only used for the internal voltage regulators which are replaced by custom regulators.

Note: The U5 IC is NOT the same as the U10 IC, and must be removed for this to work. You must also remove the 3 smd components (C1, C2, and C6) around U5 as well.

Note deux: Using an RVL-PMS-2 or RVL-PMS-Lite from 4layertech removes the need to relocate the U10 IC, as there is a special U10 pad on the PMS module that performs the same function. If you are using a 4layertech PMS: all you need to do is run a small wire from the U10 pad on the PMS, to the via shown in the bottom row of the following diagram. Removing the U5 IC is not necessary in this case.

Custom regulators

In order for custom regulators to work properly, all onboard regulator components need to be removed. It is recommended to trim the motherboard first as shown at the start of this guide to remove them before connecting the custom regulators, as the onboard regulators will cause issues and the Wii will not boot.

It is important to use the correct grade of wire for supplying power to the Wii and any attached perpherals. Supplying voltage and GND from the charge port to the batteries, from the batteries to the regulators, and from the regulators to the Wii should be done using 22AWG stranded wire (larger number = thinner wire). The Wii should also have two GND wires connected to the regulators for redundancy. Periphral components with low power requirements like the Bluetooth Module, voltage and GND for the USB drive & SD card, the controller, the audio amp, the screen, and the PW & UP pads on the 4layertech PMS and PD boards can each be powered using thinner 24AWG to 28AWG stranded wire. Using a different color of wire for each voltage is highly recommended for easier troubleshooting.

Note: Solid core wire should never be used to supply voltage or GND to any component, as thicker solid core wire is very rigid and prone to breaking under repeated stress. Solid core wire should only be used in gauges from 32AWG to 38AWG, and only to carry data signals like USB data, audio/video signals, and controller data to name a few. Enamelled Magnet Wire is the ideal type of solid core wire for this purpose, as the enamel coated wire is very thin, extremely flexible, and hard to break. 34AWG Magnet Wire is recommended, as 32AWG is still a bit rigid and 38AWG is as thin as a human hair and hard to work with for beginners. Having two colors of Magnet Wire (red, clear, and green are most common) will help make the USB and Bluetooth wiring easier.

Note: The 1v and 1.15v lines cannot be powered on the same voltage and must be connected to dedicated 1v and 1.15v regulators.


5v is not required for the board to boot. It is only used for USB, GameCube controller rumble, and the memory card slots. Consider connecting this voltage directly from the regulator to these peripherals.


Here are multiple alternate points to connect audio and video to.

In order to use VGA or YPbPr you must wire Mode to 3.3V. If using VGA, you also need to wire H/V sync to the specified pins on the AVE.

Data” pins are only required for NTSC-J consoles.

Note: When using custom regulators, the onboard audio preamp does not get 12v. You can either connect your primary voltage input to the 12v pins on the audio preamp, or use the alternate audio points located on the encoder or the bottom of the audio preamp(marked 1 and 2 on the very bottom of the first image below.)

Note Jr: When wiring for VGA video, ensure you pay attention to the legend on the left side of the image and wire the video lines by the R/G/B designation, NOT the colors painted over the pins for graphical reference. The graphic colors are for yPbPr component video, and do not match up with the RGB configuration for VGA video.


USB is required for RVLoader. It is essential for homebrew and launching games. You can directly supply 5v from your regulator to the USB port; 5v does not need to be supplied to the Wii. 32-38AWG magnet wire is recommended for the data wires, and 28AWG for 5v and GND

For each pair of USB data lines, the lines shown in green (3 & 7) are D+ and the lines shown in grey (2 & 6) are D-. It is recommended to connect the data lines to the CM1 and CM2 components for added safety, especially if using an external USB port; as a bad drive or device has potential to damage the USB data lines going to the GPU. Internal drive devices such as the PMS-PD series of boards from 4layertech do not require this step, but it doesn't hurt to have the extra layer of protection if you have the time to wire it carefully.

Note the Second: USB data lines work as differential pairs, and as such must be twisted together tightly in a helix in order to deal with interference. Twisting the USB data wires with GND wires like you would for audio/video WILL NOT DO. Line 6 must be twisted with Line 7, and Line 3 must be twisted with Line 2. Failure to do this will result in crashes, instability, failure to load games, failure to boot to RVLoader, and other annoying stuff.

GameCube controllers

GameCube controllers can be used for virtual console, as well as homebrew and standard GameCube games. The controllers only need 3.3v, data, and GND to function properly. 5v is not required, as it is only used for rumble.

SD card slot

The SD card slot is optional, and can be used for additional homebrew and save data. When trimming the board, it is advised to trim off the SD card slot to make it easier for mounting, as well as using the test points on the bottom of the board(shown below.)

Similar to wifi, it also requires soldering to resistor arrays so 32-38AWG magnet wire is recommended.

If using a 3rd party SD card slot, reference your schematic to determine reconnecting pins CD and WP, or if lacking that functionality, directly connect those two pins on the Wii to GND.

GameCube memory cards

Nintendont supports virtual memory cards eliminating the need to use physical memory cards. However, it is optional to connect them in order to save data to or from a physical card as opposed to a virtual one. This can be a useful alternative to virtual memory cards since save data cannot be easily transferred between the two within Nintendont.

5v is not required, as it is only used for specific peripherals such as the GameCube microphone.

MX chip and Reset Button

The MX chip serves various functions on the Wii, however by eliminating the disc drive and using custom regulators, only two of its functions remain relevant: GameCube font data and Real Time Clock (RTC).

RVLoader includes a custom version of Nintendont that resolves missing GameCube font data, as well as multiple emulators patched to remove that same reliance. There is no known solution to restoring RTC aside from relocating the MX chip. If you wish to use the RTC, run a wire from the positive terminal of a 3v lithium button battery to the B+ pad shown in the second MX Relocation diagram, and run a wire from the negative terminal of the button battery to any nearby ground location. Wire as thin as 30AWG can be used for this purpose.

Trim this section out of the board as shown in order to retain the required components.

Note: To activate the reset button function, temporarily connect the pin marked "Reset" to GND.


Wifi is wired directly to resistors on the bottom side of the motherboard. It is recommended to use 32-38AWG magnet wire for the data lines, as the pins are very close together.

Note: It is CRITICAL that the 6 data wires are as short as possible.


This guide is the culmination of months of research by a large group of individuals. However, since we are only human there is a chance that there may be mistakes. If you find something, please post it somewhere and tag @ShockSlayer as he has all of the original project files for the images and can make updates if necessary. Thanks for reading!

ShockSlayer - established the compendium and information standards, tested everything and accomplished the first OMGWTF trim and made all images in this guide

Cheese - initially removing mx chip and research, bluetooth and other misc testing, misc compendium work, guide work and modpack installer

Bentomo - sanding and scanning the compendium board scans, most notably down to the internal voltage layer for essentially full transparency of the board layout

Shank - documentation on board revisions, overwhelming majority of compendium work, assorted testing and initial reaching out to various members of the group

Gman - misc compendium work, testing custom regulators, original documentation, testing and inspiration

Special thanks

JacksonS - full component documentation

Ashen - for the OMGWTF name, we love you come back to portablizing

Noah - for providing BitBuilt in its early years


04-28-16 - Added alternate points to Wifi diagram. -SS
07-03-16 - Updated to reflect PortablizeMii and the current direction of Wii portablizing. -SS
07-14-16 - Updated some terminology. -SS
12-18-16 - Updated to reflect 6 layer boards and new revision guide. -SS
03-29-17 - Updated MX chip trim lines and updated relocation points. -SS
04-23-17 - Added some text about using masking tape and the unneeded inductor. -SS/Aurelio
11-05-21 - Finally replaced PortablizeMii with RVLoader, and added link -Cheese
07-05-22 - Cleaned up BB code tags rendering on post, slight wording change in special thanks to avoid confusion on if Noah currently owns BB - CrashBash
02-25-23 - Added text in the USB section to designate the D+ and D- colours and explain the essential nature of twisting the data wires - Stitches
05-07-23 - Clarified the requirement of the Bluetooth relocation with RVLoader - Aurelio
06-05-23 - Added 1.8v locations to the main voltage diagram. Added a basic explanation for restoring the RTC battery to the MX section. Added a note to the Audio/Video section to warn VGA mod users of the yPbPr graphical colours not aligning with RGB video. Added a redundancy note to the U10 section to remind users that U10 doesn't need to be relocated when using a 4layertech PMS. Adjusted the wording of the trimming warning and added a reminder to remove damaged components along the trim edge. - Stitches
08-14-23 - Revised the Bluetooth section text to advise twisting the BT data wires together for interference mitigation at Shank's request, and removed outdated text saying that the BT module is still a required relocation. Added a disclaimer about GC2Wiimote to warn users of currently incompatible motion controls. - Stitches
08-27-23 - Added a basic explanation about using the correct wire types for each pupose to the voltage section - Stitches
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