GBA SP inside DMG, all you need to know

Introduction
After I did a lot of DMG backlighting, biverting and GBC frontlighting I thought I'd give it a go and build my personal ultimate Gameboy - That's a GBASP inside a DMG's housing. I was inspired by people who did it before so this is nothing new, but I saw a lot of people asking for specific infos, so here it is...
Even if this might look like a step-by-step guide - it's NOT.
There are many ways to get this done, I'd like to share the way I did it, my joy and my frustration I've had with this project.

Please note: I'm not a native english-speaking person. If you find there's something that can be put better, please let me know. I will also update images with foreign text, so please have a little patience. Thanks!

Links

• My Picasa-Gallery with all the fullsized pictures:
  https://picasaweb.google.com/115948745418514736250/GBASPInsideDMG?authuser=0&feat=directlink
  
  
• Check out KITSCH-BENT if you need a controller PCB for this mod!
  http://store.kitsch-bent.com/

• DMG PCB with Common-Ground: (german site, sorry, I'll lead you through it if you ask nicely)
  http://circuit-board.de/forum/viewtopic.php?f=56&t=9847&p=226489#p226489

• Source of inspiration: Michael J Moffit's Site
  http://mikejmoffitt.com/wp/?p=123

• GBA Hardware Documentation:
  http://nocash.emubase.de/gbatek.htm

The mod
Ingredients:

• Gameboy DMG

• Gameboy Advance SP (we only need the mainboard and the screen)

Tools:

• (De-)solder-utilities

• Multimeter

• Dremel or rotary tool

• Hot glue gun

• Duct tape

• Some flexible wires

Here's a comparison:
left: with DMG-LCD-PCB
right: without




Different Gameboys, AGS-001 and AGS-101

AGS-001: Frontlight, (Light-Control On/Off)
AGS-101: Backlight, brighter (Light-Control Level1, Level2) [and Level 3 by patching the mainboard, see below]

So, whatever GBASP you'll be using, you have to decide if you keep the plastic srew-mounting poles inside the DMG's front-housing or if you grind them off...

-keep'em:
>> + that's a clean solution as you'll be able to use the screws to close the thing in the end.
>> - you'll have to grind the mounting-poles as well as the screen as well as the mainboard to make it all fit.

-drop'em:
>> + so you have plenty of room to align the screen and the mainboard.
>> - well, then start thinking of a way to close that thing in the end...

Here's the AGS-001 Screen (Frontlight Model)



And the AGS-101 Screen (Backlight Model)



Whatever direction you chose to mount the GBASP pcb above the screen, you may also have to grind the mainboard a little.
Watch out for leads running on the upper AND lower side of the pcb!


The screen plus the mainboard will fit perfectly and there's still enough space for everything else.





Fuses

You may find that the GBASP's fuses blow. For example if you mess around with you wiring. Also ebay-junk or garage-sale gameboys often have blown fuses.
If you have a GBASP that seems to be dead you can try bridging the fuses and see if the screen comes up.

Fuse F2 >> fast-blowing, you should check this one first.
Fuse F1 >> not-so-fast-blowing, you should additionally check this one too if bridging or replacing F2 didn't help.

Replacement-Fuses:

Where are the fuses on the GBA SP?



Desoldering components
Prepare your GBASP and desolder these parts:




Battery-Transplant

Different grinding tools sure come in handy when dealing with the GBASP's plastic cover. Also a file for some finetuning will be neccessary.
In general we'll cut off the complete battery compartment of the GBASP and make it fit inside the DMG.
On the inner side, there's a passthrough for the battery-contacts: We want to keep this intact so we can mount the contacts without hussle.



The plastic-part with the contacts will raise the compartment by 2 Millimeters, you can easily make use of a piece of plastic to make it even.

The DMG's battery door will close smoothly and the GBASP's battery is seemlessly hidden inside.



Inside the DMG we'll need to cut out a rectangle as a passthrough for the battery contacts.

Gameboy COLOR Mode

The switch right next to the cartslot reads SW13. GB and GBC cartridges are slightly larger than GBA carts so they will flip the switch when inserted.
If you short the connection you now have a Gameboy COLOR instead of a GBA.

POWER TO THE PEOPLE
Let's gain control over the On/Off-switch (SW1), that's easy because the DMG's respective switch acts in the same manner:

PLAY IT LOUD
Connecting the speaker is a breeze.

Ext.2 Connector

The EXT.2 port of the GBASP is used for charging the battery as well as connecting headphones when using an adaptor-cable.
External power input is used to charge the built-in battery, it cannot be used to run the SP without that battery.
You can mute the speaker when PIN5 connects to GND.

Now here comes the first tricky part:
The original DMG's headphone jack has a switch inside which is 'normally closed'. It closes 2 contacts when it's NOT plugged. When you plug a 3,5mm jack the connection is open.
This is of course contrary to the EXT.2 port's logic... because it closes the connection between PIN5 and GND to mute the speaker while being 'normally opened'.

The original DMG's headphone jack holds another challenge if you'd like to re-use it. There are parts and connetions that might not be suitable for your wiring. BUT... it comes with nice mountings and therefor it might be worth keeping it.

Here's the pinout of the DMG's headphone jack:

If you want to use that part make sure its connections suit your needs.

Other creative solutions for getting sound:

Pictured is a jack from a MGB (Pocket).
Source: Nex >> http://chipmusic.org/forums/topic/1443/gameboy-advance-sp-pro-sound/



Volume potentiometers

Specs of the DMG's thumbwheel (b10KOhms):


The DMG's contrast-pot has 30K, you may or may not be able to use that as a volume control.

This diagram is courtesy of benheck-forum member ModGyver:

This works really well.

The GBASP seems to control the volume internally depending on what resistance the volume-slider is giving.
On the DMG it works completely analogue: 2 inputs, 2 outputs, 1 GND.



RESET

Inside the GBASP there's a reset-trigger! If you connect it to GND the device will reboot immediately.
That's awesome, if you have a "GB USB SmartCard 64M" where you can switch the game-selection pages by switching off and on very quickly, I think resetting is much more comfortable.


I've used a switch from an old TV-chassis that fits quite well.



Link Port EXT.1

The pins are labeled on the GBASP mainboard. Simply connect all pins to the connections on the board.



Buttons and D-Pad Hijacking

Now, to hijack the controls and make use of the DMG's dpad and buttons there are different ways to do it....
Just make sure the carbon-pads underneath the buttons are making contact to the pcb when pressed.
Either you cut your DMG's lcd-pcb like this:

...or you build something on your own...
OR you can use one of these 'common ground pcbs' that board-member 'micro' made available here -> http://circuit-board.de/forum/viewtopic.php?f=56&t=9847

You may use both PINs 6 of the EXT.1 and EXT.2 ports - there are countless more GND connections to be used for this.




LEDs

All the LEDs have 1,9V inputs.
For relocating either solder wires directly to the LED's contacts or use these pads:





Brightness control (only AGS-101)





Connecting the DMG's cartslot

I've use a heatgun to optain the cartslot from the pcb. The connection is simple yet time-consuming:

If you made it till here use some hot glue to keep the wires flat and in place.




I know it's getting tight inside but it'll work...

-Have Fun-
-Alex-
​

 

cool mod, this is actually the first time I've seen this before. nice basic how to. it really helps people interested in modding

 

Excellent guide! "Save to pdf".

But I must ask about the AGS-101. When I do Color frontlight mods it's easy to get an AGS-001 with broken screen to use as donor. But in your case you take fully working screens (from the much more expensive 101) to use as donors? How? Is it that easy to find 101:s in Germany?

 

My god. It's genius. Keep up the great work! :smile-new:

 

Before you save to PDF, you might want to do that with this version: http://forums.modretro.com/viewtopic.php?f=40&t=11746&sid=01d6d9b28e69144badcba90ca7182177
because the modretro board has the

Code:

-blocks for preformatted text-output. Some Info in my guide just makes more sense with correct text-wrapping...

As for the 101s, yes, they're quite common yet more expensive than 001s. I just bought a 101 off eBay for 20 Euros, but I was lucky because the seller didn't mention it was a 101.
There are 3 ways to aquire a cheap 101:

- look out for GBA SP auctions where the item description is unclear which version it is and ask the seller
- buy defective GBASPs and bridge or replace the fuses (90% of all broken GBASPs have blown fuses)
- order a mainboard and screen from China:
Mail Zerey in China: zereyzhang[at]yahoo[dot]com (speaks english)
AGS101 screen for $23
AGS101 Mainboard for $7
plus shipping.

 

I'm curious about the Level 3 light level, is tha ta permanent mod if you wire to ground, or does it give you 3 choosable options with the lightness button?

 

This is really awesome. Thanks for posting it.

 

For You I'd do anything :victorious:
I love my RGB AV Famicom that you modded, it's just out of this world.

It's permanent as long as the pin is grounded. Also it overrides the regular setting. What I failed to achieve is finding a way to lock it into level-2. It sucks that you have to set level-2 manually when you turn on the GBA SP. But level-3 is really too bright, for sure it drains the battery in no time and it's a 'nice to have' but completely not worth installing a switch for it. I'm afraid to get eye-cancer from looking at it too long with that setting...

 

Haha glad you like it. Honestly I've built these machines for so many people I can't even keep track of who I've worked for anymore. I just noticed this guide has you perma set the gba to gbc mode. It's probably a lot more work making it able to run as a gba as well because you'd need to relocate the cartridge connector and do some other fun stuff.

 

It's finished

 

I really like the ones where people expand the screen window so you can fit a full gba screen in the dmg, but that of course is way more work.

 

Good news everyone!

Kitsch-Bent is selling the controller PCBs that I used for this mod.
I highly recommend getting one if you want to use the DMG's control-inputs, it will save you a lot of stress and time.
Kitsch-Bent is a serious and well-known seller, I spoke to Matt and he was very happy with the quality of the PCBs.

I'll post the link to the product-page within their shop as soon as the PCBs get listed.

 

I'm assuming it should have been :

Pin1 on the GBA geos to Pin1 on the DMG
Pin2 on the GBA geos to Pin2 on the DMG
Pin3 on the GBA geos to Pin3 on the DMG
....
Pin32 on the GBA geos to Pin32 on the DMG

 

You're absolutely right, sorry, my mistake!

 

Simply amazing Tut u got here Budd been wanting to test my hand at some modding with my collection of various Gameboys

 

Sorry to bring up an old thread, but I can't find the answer anywhere I've searched. What's the voltage delivered to the screen on L3 brightness? I don't want to accidentally apply excessive voltage to my display in a custom L3 mod.