Trying to revive a Gamebox DMG

[NekoNova]

Hey everyone,

first time poster, long time lurker

I'm having some issues with getting a Gameboy DMG revived that I bought of Ebay. The package contained 2 gameboys, but listed as not working. The first I had was really easy to repair since it only suffered from vertical lines.

The second one however is a complete mysterie to me.
When I insert batteries or connect up a power adapter and turn on the gameboy, the following happens:

* The "pop" in the speakers
* The red led lights up

There's no sound comming from the speakers, nor does anything at all show up on the display. I've used a Multimeter to measure the currents on various points on the board. The board holding the cardridge connects seems to be working fine and has power everywhere I meassured.

The board holding the display however was strange. I could meassure currents on various locations, but on several keypoints there was nothing to be meassured.
I replaced all capacitors already that I could. The only ones left to replace are the 1microF/50V ones on the back of the display, but bit scared of doing that since I need to go under the display with the soldering iron.

Anyone who can give out some pointers of things to check in this gameboy? Or someone who has encountered a similar situation?

 

[NekoNova]

Made some progress now.
All caps have been replaced on all the boards. Current seems to be reaching more sections of the second board now, but still no display or sound.

Getting a bit clueless now as to what else might be wrong :S

UPDATE:

I took a second Gameboy DMG and did the following:

* Took the display of the broken one and connected it to the power supply of the second one.
** Display was all dark, but the music played this time.
* Took the display of the working one and connected it to the power supply of the broke one.
** Nothing happened

So my assumption now is that the chips on the "broken" one are completely fried and beyond repair. Might salvage for parts I guess.

 

[ttsgeb]

Have you washed the boards yet? Like... with water and soap and baking soda and such?

Consumer Electronics are a lot harder to fry than a lot of people seem to think.

Also, pictures could be helpful.

 

[NekoNova]

I've cleaned the boards for the most part and used a glassfiber brush where possible to get most of the "crap" of the boards.

Here's the first batch of pictures of the boars. If needed I can make close up pictures of specific section if desired.
I would love to get this thing going again.

Display Board Front

Display Board Back

Cardridge Board Front

Cardridge Board Back

The speaker and DC converter are currently detached as I wanted to salvage them, but I will re-attach them if this Gameboy looks salvagable.

Tools I have available:
* Multimeter
* Soldering kit

 

[NekoNova]

Okay,

I tinkered around more with the broken one, and reconnected the speakers and DC converter.
The funny thing is, I accidently connected the DC Converter wrong when I attached it again. However in doing so, when I turned on the device I actually got the nintendo sound playing.

When I re-attached the connector the same as it is on the working gameboy, I get no sound whatsoever....This kinda worries/puzzles me that something/somewhere is not what it should be.

The screen however is still a no-go.
Re-attached the display to a different Gameboy, and all I get there is the bling, but the screen remains totally dark, even when playing around with the contrast wheel.



This brings me to the following 2 conclusions:

* The display board has some weird connections going on.
* The power board has a different issue, since attaching a working display to this results in nothing....

Tommorow I will try to remove all components from the power board except the ICs and try to test them out one by one to discover if anything is faulty.

 

[ttsgeb]

Scrub everything real good with a toothbrush and soapy water. Rinse it off, and let it dry real good.
There's still a lot of gunk on that board. A good wash is way easier than checking everything one by one.

 

[NekoNova]

Okay,

I've cleaned both boards as requested and took new pictures.
I hope it's clear enough to show the difference...

Display Front

The bottom right trace got damage due leaking batteries, so with my glassfiber brush I removed all goo, but this leaves the trace a bit exposed. Checked for continuity, and it works.
Sound works when using this display on a different connector board from Gameboy 2

Display Back

Again damage on the board due leaking batteries, that's the black spots. The board is really rough here. I didn't try the glassfiber brush here, as I saw no direct need for it.

Cardridge board front

I retouched several IC feet to make sure the solder joints are properly connected. Double checked all caps to be in the right order and the correct values. Board is squeeky clean

Cardridge board back

One of the pads from "copper paper???" was damage at the bottom, and I feared it was making a bad contact somewhere. That's why I cut off the corner and use a wire to get it reattached to the rest of the "copped paper???". Not really sure what the goey stuff on the right is, but having a hard time getting it off.....


So....
Ideas? Suggestions?
Behavior of both boards is still the same as described in the posts above. Willing to try anything to get this thing working again.

 

[zaxxon]

Try replacing the capacitors with this kit:
http://www.ebay.com/itm/GameBoy-Origina ... HOP:US:101

Doing so has been known to fix many weird problems when it comes to gameboys.

 

[NekoNova]

I've already replaced all capacitors with brand new ones. Same Voltage and capitance.
Solved the issue that some parts were not getting sufficient power.

I'm guessing something else is broken. Either one of the connectors on the powerboard, since this one doesn't do anything with a new display board either. This weekend I will look at the other components on the board and see what this brings.

 

[zaxxon]

I could always sell you one of my working back boards if you want

 

[NekoNova]

appreciated, but I would like to learn first what's wrong with this one
Anyways, will start a worklog this weekend to determine the cause

 

[zaxxon]

ok cool. Good luck!