Modded GBA : very high power consumption

[eldontyrell]

Hello all !

I modded my GBA with a backlit screen coming from aliexpress.
Screen is very nice but I measure the consumption and it's 350 ma, more than 3 times the normal GBA consumption.

A fresh set of alcaline batteries lasted 30 minutes.
With 2000 mha rechargeables, probably not more than 5 hours.

Any idea on what can be done to lower the consumption ?
Any brightness level I can adjust ?

Thanks !

Stéphane

 

[FAST6191]

Hmm, previous discussions made it seem like the replacement screens might actually be lower consumption.

Anyway there are dozens of different screen replacement models out there so it could be that, and it would not be the first time something cheap and nasty appeared on aliexpress and purported to be something good.

Do also check you have not got a short somewhere.

After that it will depend upon what it causing the problem. If they stuck a boost converter in the screen package to power either a CCFL or just high power LED backlight then it gets tricky, if it is just a high power LED you could well find the power for it and stick a resistor in line* with it to limit the current and thus limit the power drain. Whether you could go one further and stick a PWM circuit in there to reduce the brightness (and thus hopefully the current consumption) is a different matter.

*I vaguely recall one on the install diagrams for a replacement screen that it put the light section behind a resistor somewhere on the board, if you messed up and put it the other side then it could be that. Again though there a load of different takes on GBA screen replacements so who knows.

 

[eldontyrell]

"Hmm, previous discussions made it seem like the replacement screens might actually be lower consumption."

I wonder how this possible given that there's an additional led lighting (or something else) compared to the normal (non-lit) screen.
So at minimum, the new screen must consume more than the normal one ...
Sadly, in my case, it's consuming a LOT more

 

[FAST6191]

Yeah if it was just a backlight addon then power would have to go up. Some of the ones I have seen though have been whole replacement screens with lights inbuilt. Many of the modern screens are considerably more efficient, even with the additional load of a light for it.

 

[eldontyrell]

So I came across one of these inefficient screens ... Where can I buy some good screens then ?

 

[CMDreamer]

Why don't you try yo mod it yourself?

https://gist.github.com/grantland/8c112548b44aa87dced2

 

[FAST6191]

So I came across one of these inefficient screens ... Where can I buy some good screens then ?

I don't really know, I have not investigated this market much and not seen anybody do a proper evaluation of it all and it seems there are a few people being cowboys in among it all.
Have you tried finding the LED pins and seeing if you can put an in line resistor in it yet? A nice screen would be better of course but if you can get it working acceptably with a couple of cents worth of resistor then it makes sense to do that.

 

[eldontyrell]

Thanks.
Last question ... Connecting p1 to d1a increases screen brightness as I understand it (maybe I'm wrong). Some people don't connect it and screen brightness suit them.
Disconnecting this wire could then theorically lower the consumption ?

 

[FAST6191]

I would have to look at the diagram for the GBA and the screen for this one. I don't know what those refer to and what they do, and indeed if this screen does something different to things I have seen before. I imagine it is either a higher voltage source or one capable of delivering more current but without seeing what goes I can not say.

 

[Zmajchek]

"Hmm, previous discussions made it seem like the replacement screens might actually be lower consumption."

I wonder how this possible given that there's an additional led lighting (or something else) compared to the normal (non-lit) screen.
So at minimum, the new screen must consume more than the normal one ...
Sadly, in my case, it's consuming a LOT more

Hi Eldontyrell,

if your GBA is 40 pin model you can buy these two items from aliexpress and they are guaranteed to work.

Screen:
https://www.aliexpress.com/item/For...M-Backlit-Brighter-Highlight/32622199888.html

Adapter (choose 40 pin B from the list)
[URL='https://www.aliexpress.com/item/32Pin-40-Pin-A-B-For-GBA-Ribbon-Cable-AGS-101-Backlit-Adapter-Screen-Mod/32716977370.html']https://www.aliexpress.com/item/32P...1-Backlit-Adapter-Screen-Mod/32716977370.html[/URL]
[URL='https://www.aliexpress.com/item/32Pin-40-Pin-A-B-For-GBA-Ribbon-Cable-AGS-101-Backlit-Adapter-Screen-Mod/32716977370.html'][/URL]
I have bought these two items and I couldn't be more satisfied with them. I didn't solder the additional wire because default brightness is more than enough for indoor use. Check out the photo to see the quality of the screen for yourself.

 

[Sliter]

Hi Eldontyrell,

if your GBA is 40 pin model you can buy these two items from aliexpress and they are guaranteed to work.

Screen:
https://www.aliexpress.com/item/For...M-Backlit-Brighter-Highlight/32622199888.html

Adapter (choose 40 pin B from the list)
https://www.aliexpress.com/item/32P...1-Backlit-Adapter-Screen-Mod/32716977370.html
I have bought these two items and I couldn't be more satisfied with them. I didn't solder the additional wire because default brightness is more than enough for indoor use. Check out the photo to see the quality of the screen for yourself.

wow I was wanting to mod my GBA too but why these gbasp screen cost that much?o_o I was thinking like getting a full refurbish of my old GBa, (like rechargeable battery mod and maybe changing the case ) but wasn't waiting the screens to cost that much lol

 

[eldontyrell]

Hi Eldontyrell,

if your GBA is 40 pin model you can buy these two items from aliexpress and they are guaranteed to work.

Screen:
https://www.aliexpress.com/item/For...M-Backlit-Brighter-Highlight/32622199888.html

Adapter (choose 40 pin B from the list)
https://www.aliexpress.com/item/32P...1-Backlit-Adapter-Screen-Mod/32716977370.html
I have bought these two items and I couldn't be more satisfied with them. I didn't solder the additional wire because default brightness is more than enough for indoor use. Check out the photo to see the quality of the screen for yourself.

Hi Zmajchek,

Thanks for your answer.
Hmm a pity I didn't read your answer previously.
I have ordered another screen.
Anyway, maybe I'll try this one (I have 3 GBA to convert).

BTW what is the difference between Ribbon Type A&B ?

Thanks,

Stéphane

 

[Zmajchek]

Hi Zmajchek,

Thanks for your answer.
Hmm a pity I didn't read your answer previously.
I have ordered another screen.
Anyway, maybe I'll try this one (I have 3 GBA to convert).

BTW what is the difference between Ribbon Type A&B ?

Thanks,

Stéphane

Hi Stephane,

sory for such a late response. I believe that you have already found out the answer for yourself, but if you haven't — the thing is that the type B adapter just works best with the particular screen that I've suggested to you. There are no known issues and I have bought this combo myself (screen + adapter) after reading about it here on these forums and on reddit.