AGS-001 screen in AGB-001, a blast from the past!

[Lingwendil]

I'm getting ready to retrofit just the frontlight assembly into an AGB so I figured I'd start a thread on the process as its a less common modification these days. I happen to really like the 001 screen for various reasons, and often have the frontlight off entire for outdoor use.

No, I have no desire to "upgrade" to an IPS screen.

The pics are proof of concept that a typical 32pin AGB to AGS 34 Pin ribbon functions properly on the stripped (no lighting) 34 pin SP AGS-001 screen. The SP 001/101 screens share the same pinout- the only difference is the two lighting pins (33/34) voltage requirements. The light is switched on/off or dimmed through the ground leg, and receives constant +5 or +13~ volts depending on configuration.

I also posted the schematic for the AGS-001. You can see the circuit used to run the LED frontlight- instead of a single resistor it uses a current sink in the negative leg of the lighting circuit, with the positive side tied straight to +5 volts. The way that LEDs work running it straight to an unregulated power source will be less efficient and will give lower light output as the battery goes down in voltage.

The AGS-001 frontlight as measured on my personal SP runs at 3.2 volts. Doing the math based off of the current sink and the 5 volt supply voltage shows it runs at about ~40mA. A 47R series resistor from the 5 volt line should work to run it.

I'll post more progress once my 001 screen assembly comes in the mail from ebay.

 

[hippy dave]

I opted for an ITA screen from a DSi, but any back-in-the-day pixel grid screen option gets my seal of approval and it makes sense to go for the one that you like most for familiarity/nostalgia.

Good luck & have fun!

 

[Lingwendil]

Still has to come apart for some dust between the screen and lens, but AGS-001 frontlit LCD mod is done. Still may add a light switch but it looks great! Very different look to an IPS screen and really, really nice mod. I added some masking tape in the corners to prevent light bleed through the shell and it worked very well.

Using the common 32 pin ribbon adapter you need to desolder the frontlight from the back of the LCD or you will not get a picture. Im sure you can also cutctraces on the ribbon but i opted not to modify the ribbon.

After doing this you can run wires directly to the frontlight ribbon and run the negative to the negative battery terminal or any ground lead. I then ran the positive lead to the upper end of C56 through a 47 ohm resistor.

The whole thing is a very tight fit, but it fits! You just need to remove the rubber gasket and clearance some of the foam on the back of the LCD assembly to make a smidgen more clearance for the ribbon adapter latch.

 

[yankii]

Wait, I thought only AGS-101 screens could be added to an AGB?

 

[Lingwendil]

Nope, the whole procedure is actually simpler with the AGS-001 screen, you just need to power the lighting differently. The AGS-001 frontlight takes 5 volts rather than the ~13 volts of the AGS-101 screen. This avoids having to put a boost SMPS or brightness control scheme in. You simply provide 5 volts through a resistor and a ground connection, and a switch if you want one. I didn't even need to adjust the potentiometer on the AGB, as it looks great and functions perfectly.

The LCD assembly itself has the same pinout regardless of 001/101 application, the only functional difference is the lighting is powered differently. Pins 33/34 jump to the lighting ribbon at the back of the LCD.

 

[Kuri3]

do you have instyructions for a 40pin ribbon install?

 

[Sono]

do you have instyructions for a 40pin ribbon install?

The 32-pin AGB is perfectly pin-compatible with the AGS screen (minus the frontlight on the last two pins).

The 40-pin is not simple at all. tl;dr is that you need extra components, and there is no way to get around that, the display will not work, or it will be damaged, if it's not driven correctly.
The 40-pin needs bias voltage generation (V0 to V4), on top of external COM generation (some of the circuitry is embedded on the 32-pin, but you need an external PNP-NPN setup on the 40-pin).

So yeah, sadly there are not so much instructions, as it absolutely needs extra circuitry.

 

[Kuri3]

The 32-pin AGB is perfectly pin-compatible with the AGS screen (minus the frontlight on the last two pins).

The 40-pin is not simple at all. tl;dr is that you need extra components, and there is no way to get around that, the display will not work, or it will be damaged, if it's not driven correctly.
The 40-pin needs bias voltage generation (V0 to V4), on top of external COM generation (some of the circuitry is embedded on the 32-pin, but you need an external PNP-NPN setup on the 40-pin).

So yeah, sadly there are not so much instructions, as it absolutely needs extra circuitry.

i am a complete noob in about the signals that pass thruu the ribbon, but if you tell me i can retrace the ribbon to adjust the pin positions to acomodate a ags001 screen on a gba 40 pin i would like to try [still new into modding but got a microscope and i am confortable with microsolder]

Post automatically merged: Oct 20, 2025

the price of the ribbon compared to a ips kit is too good to not try(and i have like 4 sp screens here, so nothing to lose)

Post automatically merged: Oct 20, 2025

by the way there is this post from 10 years ago about ags001 screen on a gba, and by the photos he has a gba cpu 03 with should be a 40pin board...https://gbatemp.net/threads/ags-001-screen-light-assembly-into-og-gba-mod.368171/

 

[Sono]

i am a complete noob in about the signals that pass thruu the ribbon, but if you tell me i can retrace the ribbon to adjust the pin positions to acomodate a ags001 screen on a gba 40 pin i would like to try [still new into modding but got a microscope and i am confortable with microsolder]

Post automatically merged: Oct 20, 2025

the price of the ribbon compared to a ips kit is too good to not try(and i have like 4 sp screens here, so nothing to lose)

Post automatically merged: Oct 20, 2025

by the way there is this post from 10 years ago about ags001 screen on a gba, and by the photos he has a gba cpu 03 with should be a 40pin board...https://gbatemp.net/threads/ags-001-screen-light-assembly-into-og-gba-mod.368171/

You cannot just rearrange the pins on the 40-pin and the 32-pin (although, the digital section is actually a perfect match between the 40-pin and the 32-pin, except that the 32-pin is upside-down), the 40-pin needs additional voltages generated externally, whereas 32-pin generates those in the chip on the display itself.
Do not try to just convert between 40-pin and 32-pin, you will not see anything, and you will damage the display.
Also do not try dumb 32-pin to 40-pin adapter. You need to take 1 or 2 extra signals from the GBA motherboard to the adapter to make it 100% compatible, or use a converter circuit to convert the signals back to what the 32-pin screen expects.

The reason you can use IPS on both 40-pin and 32-pin, is because the IPS screen doesn't need the custom voltages.
Also, watch out with the old tutorials. You will get ghosting / burn-in, it will damage the display. We know a lot more these days, and know how to avoid them.

---

But yeah. If you *really* want AGS on 40-pin, I can try making a converter circuit for cheap (edit: oh, I meant cheap in component cost, I'm against withholding information). I have the pinout for both 32-pin and 40-pin that I made myself, not taken from others, so it's guaranteed accurate. I also understand the signals and the voltage of the LCD, so I know how to drive it properly without damaging the display.

Give me a few days to sketch up pinout conversion and compatibility table.

Luckily 32-pin GBA is exactly the same as AGS (minus the two frontlight pins at the very end), so that part can be simplified in the table.

 

[Kuri3]

You cannot just rearrange the pins on the 40-pin and the 32-pin (although, the digital section is actually a perfect match between the 40-pin and the 32-pin, except that the 32-pin is upside-down), the 40-pin needs additional voltages generated externally, whereas 32-pin generates those in the chip on the display itself.
Do not try to just convert between 40-pin and 32-pin, you will not see anything, and you will damage the display.
Also do not try dumb 32-pin to 40-pin adapter. You need to take 1 or 2 extra signals from the GBA motherboard to the adapter to make it 100% compatible, or use a converter circuit to convert the signals back to what the 32-pin screen expects.

The reason you can use IPS on both 40-pin and 32-pin, is because the IPS screen doesn't need the custom voltages.
Also, watch out with the old tutorials. You will get ghosting / burn-in, it will damage the display. We know a lot more these days, and know how to avoid them.

---

But yeah. If you *really* want AGS on 40-pin, I can try making a converter circuit for cheap (edit: oh, I meant cheap in component cost, I'm against withholding information). I have the pinout for both 32-pin and 40-pin that I made myself, not taken from others, so it's guaranteed accurate. I also understand the signals and the voltage of the LCD, so I know how to drive it properly without damaging the display.

Give me a few days to sketch up pinout conversion and compatibility table.

Luckily 32-pin GBA is exactly the same as AGS (minus the two frontlight pins at the very end), so that part can be simplified in the table.

i would be very happy if you do it for me

 

[Aoba964]

The 32-pin AGB is perfectly pin-compatible with the AGS screen (minus the frontlight on the last two pins).

The 40-pin is not simple at all. tl;dr is that you need extra components, and there is no way to get around that, the display will not work, or it will be damaged, if it's not driven correctly.
The 40-pin needs bias voltage generation (V0 to V4), on top of external COM generation (some of the circuitry is embedded on the 32-pin, but you need an external PNP-NPN setup on the 40-pin).

So yeah, sadly there are not so much instructions, as it absolutely needs extra circuitry.

Greetings, while searching how to plug 001 screen into AGB, I found out that special ribbon that people use is actually a little modified ribbon for AGS-101, with an additional resistor added and soldered to C56 on AGB PCB. Can you undertsand what they done there?
I'm planning on using the generic ribbon with 56 Ohm resistor soldered above what already on 40 pin ribbon from production, but I want to hear someone else opinion, and since this mod is pretty lacking on information, anything will be useful. Thanks.

 

[Sono]

i would be very happy if you do it for me

Oh my god, I'm so terribly sorry, I have *completely* forgot to do this

I'm in a slightly better situation now, so hopefully I will remember to actually finish the drawing...

Just in case something were to happen, let me leave some information on the constraints of the mod.

Spoiler: Technical data

Pinouts are surprisingly compatible, with some notable differences.

• pin1 and pin27 on 40-pin are missing completely on 32-pin
• VSHD (pin5 on 40-pin, pin7 on 32-pin) and DGND (both pin6) are swapped, grrrr...
• the bias voltages are missing on the 32-pin (pin36 (V4) to pin40 (V0) on 40-pin), it's handled on the Chip on Glass now instead of on-board AGB-REG, hence REVC (pin27 on 32-pin) is so important to hook up properly via a wire soldered to the board
• VCC (collector, pin32), and VEE (emitter, pin30) are missing from 32-pin, it's also handled by REVC in on the Chip on Glass
• VSS (source, pin31 on 40-pin, pin29 on 32-pin) and VDD (drain, pin33 on 40-pin, and pin28 on 32-pin) are also "swapped", bleh
• 34-pin AGS screen has backlight on pin33 and pin34, otherwise it's exactly the same as the 32-pin... seriously!

To get from 40-pin to 32-pin pinout, delete the missing pins by "collapsing", so the nearby pins get "squeezed". So if you have 1,2,3,4 for example, and pin3 is missing, you get 1,2,4 as a result.

I did look closer to the board, and it seems like I have accidentally mis-traced a few traces.
It *may* be possible to use a transistor and a few resistors to level-shift from the capacitively coupled VEE (pin30 on 40-pin) to control REVC without a wire to the board, but I'll have to ask someone first to make captures to see what I have to deal with.

Greetings, while searching how to plug 001 screen into AGB, I found out that special ribbon that people use is actually a little modified ribbon for AGS-101, with an additional resistor added and soldered to C56 on AGB PCB. Can you undertsand what they done there?
I'm planning on using the generic ribbon with 56 Ohm resistor soldered above what already on 40 pin ribbon from production, but I want to hear someone else opinion, and since this mod is pretty lacking on information, anything will be useful. Thanks.

My heart dropped when I read C56, because that's the very first capacitor that is in front of the regulated 5V output...
1) the ribbon already carries 5V input as VSHA input (pin34 on 40-pin, pin31 on 32-pin), so I don't get why you'd have to tap it directly from the motherboard (besides voltage fluctuations on VSHA causing disturbance on the screen)
2) I do not like the notion of 5V being connected to *any pin*, with or without a resistor, as not only does no other pin accept 5V (besides VCOM in, and obviously, VSHA), digital pins are reference to VSHD (VDD3), not 5V, so that doesn't sound so good for the lifespan for the Chip on Glass...

Even if we try to correct it to C54 (which is directly connected to the output of the contrast pot, on the side closer to the contrast pot), it still doesn't make sense, as again, that is routed directly to pin29 on the 40-pin connector (and pin30 on 32-pin), so why bother with a wire, when it's already on the ribbon...

If anything, you'd want to take the REVC input from the board, and feed it directly to the poor 32-pin LCD (on pin27). V0 to V4 voltage generation happens on the Chip on Glass (as opposed to AGB-REG on the GBA PCB with the 40-pin), so if we edge the REVC input with two precision resistors (like some mods do), then that will just slowly bake the LCD panel...

Do you have a higher quality screenshot of your particular ribbon? I need to trace it to see if it can even be modified to be safer.

 

[Aoba964]

Do you have a higher quality screenshot of your particular ribbon? I need to trace it to see if it can even be modified to be safer.

I don't have them on my hands right now, so I can't make photos at this moment, but I found a few screenshots of it

 

[bjaxx87]

Nice work!

Since it seems the experts are present, one quick question: I bought an AGS-101 screen inside an AGB-001 at JAYBOYMODZ, but the screen flickers heavily which is extremely noticeable when playing GBC games. Isn't there some simple fix (like adjusting a potentiometer) or is this to be considered normal on old screens like this?

 

[Aoba964]

Nice work!

Since it seems the experts are present, one quick question: I bought an AGS-101 screen inside an AGB-001 at JAYBOYMODZ, but the screen flickers heavily which is extremely noticeable when playing GBC games. Isn't there some simple fix (like adjusting a potentiometer) or is this to be considered normal on old screens like this?

Yes, adjusting potentiometer should do the job, basically as simple as screwing the screw, but be careful, if you somehow break it, you will have hard time replacing it

 

[bjaxx87]

Thank you, I will give it a try and be extra careful. I just ordered the screwdriver.

 

[Sono]

Thank you, I will give it a try and be extra careful. I just ordered the screwdriver.

You can use anything that fits, as long as you don't damage it.

Remember, that this is not an actual screw, and it's super delicate. Even just touching it is enough to better or worsen the flicker.
Although, if it's really bad, you can do small* adjustsments instead of microadjustments to see which direction is better, and which direction is worsen.

* small adjustments are so small, that if you look at the before and after, you should be able to tell that you have rotated the head a bit, but not any more than that

Edit: oh, and just in case you manage to keep your SP on with the battery removed: completely remove the thing you're adjusting it with (especially if it's metal!), because any extra capacitance will *also* change the flicker amount.
Yes. Just having the adjustment tool present is enough to throw the adjustment off...

 

[bjaxx87]

You can use anything that fits, as long as you don't damage it.

Remember, that this is not an actual screw, and it's super delicate. Even just touching it is enough to better or worsen the flicker.
Although, if it's really bad, you can do small* adjustsments instead of microadjustments to see which direction is better, and which direction is worsen.

* small adjustments are so small, that if you look at the before and after, you should be able to tell that you have rotated the head a bit, but not any more than that

Edit: oh, and just in case you manage to keep your SP on with the battery removed: completely remove the thing you're adjusting it with (especially if it's metal!), because any extra capacitance will *also* change the flicker amount.
Yes. Just having the adjustment tool present is enough to throw the adjustment off...

Woah, thanks, that will be super helpful once I get around to give it a try! I ordered a screwdriver to open my GBA, not to adjust the potentiometer.

 

[Aoba964]

Do you have a higher quality screenshot of your particular ribbon?

So today I recieved it. Here it is - identical to the one I found on internet.
I also have access to multimeter, so if you want me to check continuity, just point where or what to do
Also note - behind adhesive is metal plate, I think it soldered to AGS connector, thus cannot be removed, at least, with my skills without breaking ribbon. But if you really need to, I don't mind destroying one in order to get you more info on wiring.

 

[Jayro]

I must be the only person in the world that can't stand the AGS-001 screen...