Game Boy™ DMG Bi-vert Chip Installation

No cut traces! I will guide you through the steps required in cleanly de-soldering the FFC connector pins leaving the DMG unscathed.

Pins 15 and 16 on the FFC connector are the data lines from the CPU to the LCD, which we're going to proxy through the bi-vert chip.

Be warned: Please remove all batteries before continuing. It's also advised to do this outside of the DMG shell to avoid any accidental slip and melts.

The materials used in this instructable are relatively available online and easily substituted. I predominately use MG Chemicals products as their manufacturing and packaging facility is local. It is important to support your local businesses and I strive to support my local hobby, electronic, and surplus suppliers. My favourites are: A-1 Electronic Parts, Component Electronics, Sayal Electronics, and AA Electronics. For those products I can't source locally I use online distributors — for electrical components they're DigiKey or Mouser and for supplies they're Amazon, eBay, and AliExpress to name a few...

The solder station used is a Hakko FM-202 with a FM-2021 iron and T7-D12/D16 tip. It may be on the high end for a once in awhile mod but I'd recommend to keep an eye out for an equally mid to high end station from your local and online surplus or government auctions such as: govdeals.com and bidspotter.com (US/Canada), torontosurplus.com (My local place), etc. As an intermediate I'd recommend a Yihua 936 which is a sub $20 Hakko 936 look-a-like if you don't want to jump into a Hakko FX-888D.

Step 1: Identify Pins 15 and 16 on the 21 Pin FFC Connector

You can either follow the traces from the test pads, or simply count the pins either backwards from 21 or forwards from 1, as indicated on the mainboard.

Step 2: Optionally Apply Flux to Pins 15 and 16 to Help Facilitate in the Removal of Their Solder Joint

Any flux should do and is optional if your de-soldering braid contains it.

The flux pen used in the image is MG Chemicals Rosin Flux Pen 835-P.

Step 3: Place De-soldering Braid Over and In-between Pins 15 and 16, and Apply a Heated Iron

Let the de-soldering braid soak up the solder as you apply the heated iron tip. Don't apply too much heat at any given time, as to avoid damaging the underlying pad. Repeat the application of the heated iron tip to the de-soldering braid until all the solder forming the joint between the pin and the pad has been removed as it may take a few attempts. If need be, use a hobby or utility knife to provide a minimal amount of leverage under a stubborn pin to lift it from the pad and continue with the braid to remove any excess solder.

The pins will have a minuscule spring to them when the solder joint is no longer. To verify, slide a piece of paper in-between the pins and their pads. If the piece of paper moves freely until it hits the plastic casing of the FFC connector, you're set for the next step.

If you'd like to be thorough, you can use a multimeter in continuity mode, probing each pin and their corresponding pad; If you hear a "beep" you've still got a short.

The de-soldering braid used in the image is MG Chemicals Fine Braid Super Wick 0.05" (Yellow).

Step 4: Clean Any Remaining Residue

Using a foam or cotton swab and either flux cleaner or a high percentage Isopropyl, swab the area clean of any residue.

The Isopropyl used in the image is Walmart Equate™ Brand and the cotton swabs are Q-tips®.

Step 5: Slide-in a Piece of Kapton® (Polyimide) Tape In-between Pins 15 and 16, and Their Underlying Pads

The Kapton® (Polyimide) tape is used as barrier in preventing the accidental bridging of the pins and their underlying PCB pads when soldering and in the long term.

Cut a piece of Kapton® (Polyimide) to your desired size, but no smaller in width than the distance between pins 14 and 17, roughly 1/8 of an inch or 3mm wide.

It's far easier to use tweezers to wield the piece in-between than using your fingers. Afterwards, cut off any excess length.

The tweezers used in the image are Vetus ESD-13 and the Kapton® (Polyimide) tape used in the images is Saint GobainFuron K350 2mil; any will do.

Step 6: Identify the Data, Ground, and Power Pads for the Bi-vert Chip on the DMG Mainboard

Please note that there are many power and ground points you may choose, I chose those in closest proximity to the data points; use what works for you. You can discover more by using a multimeter in continuity mode.

Step 7: Identify Data, Ground, and Power Pads on Your Bi-vert Chip

All bi-vert chips share common inputs and outputs, but they may not share a common footprint.

The bi-vert chip in the images is my soft-latching rendition. It has the added feature of changing the display state by the press of a button. It also shares the same pad array footprint found on the DMG mainboard, thus providing a clean and simple installation. Pads 15 and 16 are conveniently broken out from the top to the bottom of the PCB allowing for a CPU or FPC side install. The 1st image is my prototype, while the 2nd image is production ready in a lower profile. For more information please check out the website.

Step 8: Optionally Remove Existing Solder on the Data, Ground, and Power Pads on the DMG Mainboard

Although not necessary, you may remove the existing solder filling the through-hole pads for data, ground, and power. This may or may not ease the installation of a bi-vert chip, but should prevent any unnecessary cold solder joints. Please note that they will be reflowed at a later step, skip if you're uncertain.

Use de-soldering braid or a de-soldering pump, which ever you prefer.

Step 9: Continue to the Next Step for an FFC Side Install or Jump to Step 13 for a CPU Side Install

I prefer the CPU side install, Step 13, because the position of the push-button switch is perfectly aligned to the groove in-between the top and bottom halves of the housing, making the drill hole inconspicuous.

Step 10: FFC Side Installation

Step 11: Position and Solder the Bi-vert Chip to the DMG Mainboard (FFC Side)

If you're using a soft-latching bi-vert module and have a reed switch, skip to Step 20, before continuing this step.

Align the through-hole pads of the bi-vert chip and the DMG and add solder.

It's best advised to initially only solder the power through-hole pad to keep alignment while you focus on the FFC pins. If you find it too difficult to solder the FFC pins, you'll avoid the struggle of safely removing the bi-vert chip for use on the easier CPU side install because only the power through-hole pad is holding it in position.

Step 12: Skip to Step 19

Step 13: CPU Side Installation

Step 14: Solder 4 Leads or Wire to the Data, Ground, and Power Pads on the DMG Mainboard (CPU Side)

You may use resistor or capacitor lead cut-off, jewelry head pins, or Kynar® (PVDF) wire. If needed, use a 3rd hand tool to assist in holding and positioning each as you solder.

Don't forget to re-flow all pads if you had removed their existing solder in-fill.

Step 15: Position and Solder the Bi-vert Chip to the Extended Leads on the DMG Mainboard (CPU Side)

Step 16: Solder Separate Kynar® (PVDF) Wire (30 AWG) to Pins 15 and 16

Cut each individual wire to your desired length. Strip roughly 1/16 of an inch or 1 to 2mm of insulation. Tin the exposed core and the pin, if necessary. If needed, use a 3rd hand tool, position and hold the the wire in-place while gently fusing the exposed wire and pin with a dab of solder.

The Kynar® (PVDF) wire used in the images is OK Industries KSW30B-XXXX.

Step 17: Solder the Kynar® (PVDF) Wires From the FFC Connector Pins to Their Corresponding Pads on the Bi-vert Chip

Step 18: Cut Any Excess Lead Wire and Clean Any Residue

Using a foam or cotton swab and either flux cleaner or a high percentage Isopropyl, swab the area clean of any residue.

Step 19: Optionally Drill Access Hole to Push-button Switch (*Soft-Latching Bi-Vert Module)

Prepare by measuring the distance from the top lip of the bottom housing to the push-button switch using a small piece of paper. First, slide in a piece of paper. Second, fold the paper over the the top lip and score it with a pencil. Third, using a sharp tipped pencil mark the top of the push button on the paper. Fourth, remove the paper and place it on the outside portion of the housing and mark your drill point. Keep the mainboard with your bi-vert installed in the housing as your center guide.

Please don't drill using high speed power tools, you will inadvertently melt the plastic housing. A nice sharp drill bit and hand power is plenty enough. Using a 1.0mm drill bit and finger turning power, begin to drill your hole, periodically removing the bit and blowing away excess plastic. As you near the end of your borehole, remove the PCB from the housing and proceed to a nice clean exit.

The drill bit used in the image is a Union Tool 1mm Carbide 2 flute PCB drill bit.