GameBoy Lighe EL malfunction

[royal raven]

Hey folks,

I have a pretty clean gameboy light with a non working EL panel.

I got it almost 10 years ago in a junk order on ebay, shell was pretty beat up and backlight didnt work. Screen is pretty good tho. it's sat in a shoebox until I saw those new GBL shells, so now its a shiny gameboy pocket with AAs haha.

TL;DR: I dont think it's the power switch, the capacitors, or the EL panel or the "AC transformer". I want to repair it without an IPS.

Heres the long version: I really want to fix this thing and keep it as original as possible. I have enough IPS screen mods, I'd like to salvage this with some kind of EL panel.
The power switch was snapped and dirty, so I glued it back together and cleaned it but no go. Being 25 years old, I figured it might need a new capacitors, but that didnt fix it. So i figured its the EL panel, but I just got a replacement with a power supply (that I can cut to size) and out of curiosity I tried the original EL panel and it works with the seperate power supply. Which means something is wrong with the board? Which is weird, cause when I switch from "on" to "on/light" I can hear the classic EL inverter hum so I think part of it works at least? I know that's important to power the panel, but it looks and sounds pretty great to me too? I'd test continuity but I don't know where should be connected, or how to avoid a shock lol. Maybe theres a schematic...

I'm at a loss, I don't see any corrosion or anything obvious to replace. Does anyone have any advice?

I misspelled the title... dang, dont think I can edit. Anyways, any help or suggestions would be greatly appreciated 🙂

Edit#2 [I'd like to repair it without an IPS] *OR an LED backlight, really trying to get the EL working

[noble elm]

Sometimes the contact pads where the EL panel ribbon touches will get dirty and have poor connection which could be your problem

[royal raven]

Thanks for the suggestion! I tried cleaning both the pcb and el panel with IPA already. Just tried again to double check and no go :/

Wait, I just saw this white spot on this, is this intentional paint or something leaking out?

Its on the back of the consoles power regulator

[noble elm]

It is intentional paint

here's mine

[vestal arrow]

there are schematics pinned in #troubleshooting-archived

[royal raven]

Dang, thanks for checking!

[royal raven]

Oh ok awesome. Idk how to read the legit schematics, but ill try using the color coded guide after work to see if I can find any broken leads

[royal raven]

@vestal arrow Dang, so I’ve tested every connection that seems related to the el wire pads, and the ac converter, and the power switch, as well as a other traces around them, and everything seems to be connected how it’s supposed to. I’ve shined a light through it and everything is unbroken… There’s zero signs of corrosion or anything like that.

I’m thinking maybe something is up with this power chip? I don’t think I could replace it with a gameboy pocket one tho.. I haven’t looked yet but I imagine they have power set up differently?

That or the caps I bought from RGRS are bad? But idk how to measure capacitance..

If it WAS the power daughterboard, it’s weird that everything else works perfectly… idk what’s up

Actually maybe its more simple and I'm being dumb...

Is this lead coming off the positive EL pad supposed to be connected somewhere else?

I never understood why traces would go up to these holes and disappear on the other side, is it going inside the pcb?

(Image is mirrored btw, but still)

I wonder if theres a way to measure the AC current to see if the inverter is working?
When I switch it on it makes the high pitch whine that I'm used to, so I assumed it works, but maybe not...

[noble elm]

maybe the EL is worn out you can buy some other EL panels and solder the wires to the pads on the board

there's a video of a guy doing it here's the video :https://www.youtube.com/watch?v=w5ckECRjgRo

[vestal arrow]

you can get about 70VAC from the EL pads. if youre not getting anything out of it you can use the schematics. it has the voltage rails labeled

[royal raven]

Great minds think alike. I saw that vid and ordered a replacement which came with its own AA power supply. Out of curiosity I connected the oem EL panel to the new power supply, and it's extremely bright, definitely not worn out :/

So I think its something to do with the board

[royal raven]

Hmm ok. So I learned how to measure AC voltage, but it seems like nothing is coming off the chip. Off the seperate power supply I'm getting a reading so I know the multimeter is set right

Seems like the oem inverter isnt working, even though its making the high pitched hum :/

I found the part of the schematics referring to the inverter, but I don't know how to interpret it (beyond a basic level), or how to learn...

Seems like I'll have to repair or replace the inverter?

I was thinking about trying to chop up the inverter that came with the new one and shoving it into the case neatly lol.

This would work, but I think the power draw is very high, besides it uses a momentary trigger to turn on so I couldn't use the power switch. And it has an annoying flashing mode so this would all be far from ideal.

[royal raven]

Hmm, maybe it's one of the transistors? Do those go bad?

Either Q3 or Q4?

Damn, regardless seems like I have a lot to learn if I wanna fix this