Hello! I'm just getting into chiptune and just joined the forum. Anyway I finally got an EMS cart with LSDJ. I have a biverted HHL V2 pink backlight and the Kitsch-Bent/Thursday Customs RGB backlit start/select buttons set to pink. Everything worked fine until I added the EMS cart into the mix. While using the EMS cart I have had contrast issues and an over-heating problem (the regulator board would get hot and smell of electrical). I searched the forums and the internet. I couldn't come up with much. A few posts mentioned the EMS carts having a power draw problem but that it was fixed back in 2010. I did what I could. I checked all my solder points and eventually moved them directly to regulated power. That lessened the contrast issue but not the over-heating issue. I recapped the gameboy. Which seems to have solved the over-heating issue (I haven't been able to test it for an extended period of time because some of the caps where too big in the kit and I can't close the case. I'm waiting on new ones). From the bit of testing I could do the contrast fluctuations are still present. A few things I forgot to mention. I have the included resistor installed with my backlight. I know LSDJ has a power save setting but the contrast issue also occurs with normal games that I have on the other page of the EMS. I see a lot of people with backlights and even more LED mods than me using the EMS carts with seemingly no problem but a lot of those seem to PIL gameboys which if I understand correctly have a revised regulator board. I have the first version with only a single capacitor. So fiiinnnallyy lol my question is: Is there anyway to beef up the regulator, say with a different cap with higher capacitance? Or alternately would it be possible to transplant the revised regulator from a donor gameboy? Really any suggestions on potentially fixing the problem would be more than welcome.
I believe the resistor for the backlight is either 100 or 150 ohms. Would you have a suggestion where to start with a resistor for backlit start/select RGB module? I have the included resistor for the backlight soldered directly to connection tab so I'd have to take the backlight back out to switch it out for another which I'd rather not do if I don't have to. Would installing a second resistor where it connects to power cause a problem? (I wouldn't think so but I thought I'd ask. Better safe than sorry)
Ok, thank you. I'll start out with trying to add another resistor to the backlight. I guess I could try to get into contact with Kitsch-Bent or Thursday Customs to see if they have any advice on using resistors with the start/select RGB board.
After thinking about it and looking around a bit I think I'm probably just going to take your second bit of advice about trim pots. I think I'll get the Variasuit Mod from Nonfinite and just hook it up to both. It seems pretty small, and discreet. That way I can turn down the brightness while using my EMS cart and turn it back up when I'm using normal carts.
Is it the pot itself that won't last or will it negatively effect the life of the LEDs? I like the idea of using the trim pots and they're fairly cheap, so if the pots go bad I'd be ok with that I guess.
Last edited by Kye_Robot (Apr 4, 2016 2:13 am)
Why not power the backlight BEFORE the reglator?
Makes zero sense to load up a very weak converter.
Yes it will dim as your batteries drain but not enought to be an issue
*any* loading to the regulator will increase ripple, it is in the design of a switching converter. If the idea is ultimately cleaner sound, adding an LED to the regulated 5v is not the best idea. If you want a constant brightness you can drop in a constant current supply. There's the easy way to do something, and then there is the right way.
Apeshit, not meant to be an attack at you. All I am saying is SOME people go to great lengths to improve the sound out of their '30 yr old game console'. I'm sure you are aware of this. Why introduce more noise when the goal is to reduce it?
Just because it has been done a certain way in the past, it doesn't mean you have to keep it that way. If you are in the position to offer a higher quality product than the competitor, wouldn't you take it?
I'm not sure where I got my backlight from, it was maybe 3 or 4 years ago now. The LED's are soldered to flexible PCB and have onboard current limiting resitors. They are horizontal and in my opinion too bright. I'd say they consume more current than the CPU does, and I know that the noise coming from the speaker when there is no audio playing is louder than an unmodded unit. This has no impact on me playing games on it but it would be an issue if I wanted to record direct from the GB.
To be honest, with the backlight, contrast is worse, battery life is absolutely terrible. Yes I can play in more lighting conditions, and yes it looks cool but it is not something I'd do again. There is a mod you can do which will increase the contrast (not bi-vert) but is not suitable for the average 'modder'. It involves removing the LCD drive voltage regulator and replacing it with a set of tiny SMD pots. You can then change each shade's contrast value individually. Doing this you can drive the LCD harder and make blacks blacker. This would probably have an impact on the LCD's life.