Game Gear repair archive project

Started by kendrick, May 05, 2007, 06:39:38 AM

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kendrick

I've been tooling around SMSPower, ASSEMbler and some of our other friendly rivals in the web forum world over the last few days. While there's a lot of information about Game Gear repair, none of it is collected in a single location. I thought I'd start a new topic to get people fired up and interested, and hopefully contributing data that I can collect into a wiki page.

For those of you just joining us, Game Gear units have several unique features that distinguish them from other handhelds. Specifically, these are things which make them less reliable and more prone to failure when compared to other handheld game consoles. The cathode tube that runs the backlight is dodgy and runs off an internally generated 100 VAC power connection. Also, the SMD-mounted capacitors inside are prone to leakage, and require replacement for many reasons. There are also common failure points, like controller contacts and cart slot issues.

I thought I'd start with the capacitor issue. Our own Viletim has in his RGB-modded Game Gear a load of electrolytic capacitors that he's installed to replace all of the tiny SMD mounted ones. Anybody out there have a list of the specs for these components? If not, I'm fixing to crack open my spare Game Gear so I can take some pictures and write down some tiny numbers.

-KKC, being ambitious in the last week before starting a new job.

kendrick

#1
Never mind, Tim's already covered the capacitor problem:

http://members.optusnet.com.au/eviltim/ggrgb/ggrepair.html

I'm going to hunt around for some backlight data now. Yay.

-KKC

viletim

There are some other faults/fixes that I'd like to document... For instance, one of my GGs had a fault with the screen - the top 1/4 of the picture dissapeared. And i'd heard of others with the same fault (chunks of the picture not working) ,though I can't remember the cause/soultion.

Segasonicfan

#3
QuoteThere are some other faults/fixes that I'd like to document... For instance, one of my GGs had a fault with the screen - the top 1/4 of the picture dissapeared. And i'd heard of others with the same fault (chunks of the picture not working) ,though I can't remember the cause/soultion.

I had these problems with one of my GGs and it turned out it was simply some pins on the LCD connector that needed resoldering.  I imagine you came up something far more technical though :P

-Segasonicfan
MY WEBSITE: https://segasonicfan.wixsite.com/retro
I design PCBs for retro game systems :)

kendrick

It looks like there's a subset of repair related to display problems that are most often reported, based on what I've read on Usenet and in other forums. Tim, do you happen to know which capacitors are specifically related to the regulation of the cathode backlight? I'm guessing it's the 0.47 microfarad ones, but that's only because I haven't replaced those two in my own tester unit yet and so far none of my screen issues are fixed. I have also heard about the solder contact problem causing horizontal portions of the screen to disappear, so it's probably worth illustrating the old trick of slapping on the solder and sucking up the excess with a braid to fix that.

-KKC, who is presently conducting Tivo repair and so will resume Game Gear operations in a few days...

Segasonicfan

QuoteIt looks like there's a subset of repair related to display problems that are most often reported, based on what I've read on Usenet and in other forums. Tim, do you happen to know which capacitors are specifically related to the regulation of the cathode backlight? I'm guessing it's the 0.47 microfarad ones, but that's only because I haven't replaced those two in my own tester unit yet and so far none of my screen issues are fixed. I have also heard about the solder contact problem causing horizontal portions of the screen to disappear, so it's probably worth illustrating the old trick of slapping on the solder and sucking up the excess with a braid to fix that.

-KKC, who is presently conducting Tivo repair and so will resume Game Gear operations in a few days...
Yes, it's the .47uf and the two .1uf electrolytic caps that fix the backlight issues (in my 2 ASIC version anyway.  be careful to replace them with high voltage caps though as the measured voltage across is something around 10v from my testing.

-Segasonicfan
MY WEBSITE: https://segasonicfan.wixsite.com/retro
I design PCBs for retro game systems :)

kendrick

There are .1 uF caps on the board? I count three 10 uF caps on the two-ASIC board, but none that are under one microfarad except for the .47 ones on the left. Am I blind or looking in the wrong place?

-KKC, who completed Tivo repair operations more quickly than expected.

viletim

There are no .1� electro caps in there as far as I'm aware...  

Segasonicfan

QuoteThere are no .1� electro caps in there as far as I'm aware...
My mistake, I just replaced the smaller value electrolytics with .1ufs and it works fine... :P

-Segasonicfan
MY WEBSITE: https://segasonicfan.wixsite.com/retro
I design PCBs for retro game systems :)

kendrick

I'm guessing there's a lot of slop in the AC regulation then? I have buckets of .33 uF capacitors but I have to order the .47 uF units every time I need them. If you can go as low as .1 on those two caps with no ill effects, then that might save some people a lot of hassle.

-KKC, cleaning up after his cats too early in the morning.

viletim

kendrick,
Electrolytic caps have pretty lax tolerance - usualy +-20%, sometimes +50% -20% for the really cheap ones. It's also well known that they often change value with age and temperature. I wouldn't bother ordering the specific value when you've got something that's close enough...and compared to the caps that are in there at the moment (which are probably open circuit), .33�s are a huge improvement.

Segasonicfan

yeah, it works great with .1uf caps.  The values didn't strike me as being specific really, I think they chose on .47uf to save on space because they had to use high voltage caps.  ;)  So yeah, try it out, it will definitely save some hassle.

-Segasonicfan
MY WEBSITE: https://segasonicfan.wixsite.com/retro
I design PCBs for retro game systems :)

brettlee

Sorry this topic has been idled for quite awhile, so thought since I'm also currently in the GG repair fever, might as well try to resurrect this topic  ;D So how's this GG Repair Archive getting along? Any important infos to share? Yup what I noticed that in my 2 ASIC model, the 0.47 micro farad caps were responsible for the LCD (C44 is to cure the black screen problem and C45 is to cure overlapping ghost images) I was wondering if we used different values, will it be possible to improve the image quality on the LCD?

Fix_Metal

My GG has some vertical lines on the left of the screen which are not rendered. They just keep on a fixed color and nothing more.
Never put my mind onto that thing.

l_oliveira

Bad screen, sadly.

The screen works with two chips... One deals with horizontal lines and the other, vertical lines. Any of them can fail.

It's also a common problem on the 1st generation Gameboy. Kids drop their systems a lot, you see ...

brettlee

Well, yeah. Just bad LCD screen I guess. At least it displays color. LOL
I just got the bigWindow add-on yesterday and I must say, it does help abit. Magnifies the screen to a decent size and blocks out the lights, giving you a nicely luminated screen. I've yet to try different cap values for the display. I'd probly try it out over the weekend and observe the result.

acem77

can bad caps cause the sreen to flicker really fast?
my guess is yes.....

brettlee

Quote from: acem77 on February 26, 2009, 07:56:43 AM
can bad caps cause the sreen to flicker really fast?
my guess is yes.....

Hi acem77. From my experience, yes.

brettlee

Hi guys, I recently repaired 2 loose GGs, and replaced all the caps. What I noticed is the LCD for both of these has a permanent vertical 'shadow' block in the middle of the screen. Imagine the screen divided into 3 vertical bars, the middle one is darker than the 2 sides. Is there any possible way to fix it? Also what could be cause of this? GG dropped on the floor? Exposed to extreme heat?  I don't know the history behind these 2 GGs as I bought them used...

viletim

brettlee,

It's most likely a fault in an LCD column driver chip. Unforunately, they're mounted on the glass and are impossible to replace individually.

brettlee

Hi viletim. Thanks for your reply. Aww.. that's kinda sad to know.. :( Guess both of them have to remain as spares/backup units for now..

Sting310

Hello,

When I put a cartridge in and turn my GG on, it just sits with a blank screen and no sound. I have cleaned the cartridge and the GG itself, but no dice. It can use the TV adapter and I get sound, but no picture unless I tilt the screen. Finally the same happens with the SMS adapter.

Why would both of those work and not a GG cartridge??

Also, how do I tell a bad cap when I open the unit up?

Thanks,

Nick

brettlee

Hi Nick,

That's strange. Does it only happen to that one particular cartridge? If the TV Tuner works, I don't see why the cartridge wouldn't. If you have cleaned the contacts for the carts and still not getting anything, I'd recommend using an eraser to rub the cart's contact point. Rub until the shine comes back and then clean it with some alcohol. I have a GG that would 'misbehave' with my copy of Sonic 1, but it doesn't show that in any other GGs. It's strange and I still can't figure out what's with it. Other cartridges seem ok except for that Sonic 1. I'm gonna try to get another Sonic 1 and see if the same thing happens.

Leaked caps can be easily spotted.. They usually leak around the legs of the caps and are in yellowish / brownish color. But sometimes a cap may not look like it's leaked but it has dried up over time, which also need to be replaced. I recommend that you first change the obvious looking ones, and if there's still problems.. Replace all the remaining caps..

Hope this helps. Good luck!!

Tiido Priimägi

all caps should be replaced at once... less issues later on
Mida sa loed ? Nagunii aru ei saa ;)

Sting310

Any special instructions about the soldering?

brettlee

Priimagi is right. It is better to nail all those suckers once and for all.

I was typing a hell lotta instruction here, when suddenly I remembered Viletim has already documented it ..

http://members.optusnet.com.au/eviltim/ggrgb/ggrepair.html

Hope that helps.. Buzz us here if you need further help..

Sting310

I replaced the blown cap (.47UF 50V) but the unit turns on for a sec and then shuts off.

Does that center screw (the service one) have to be in for the unit to power on?

Thanks,

Nick


kendrick

You get the polarity right? That sounds like my other blue unit when I got one of the flouro tube caps backwards.

Sting310

 :-[ How do you tell the proper polarity?

kendrick

On the Game Gear boards I've worked on, most of the numbered capacitor slots (C1, C2, etc.) will have a plus sign by where the positive lead of the cap should go. Likewise, the small electrolytic and tantalum capacitors I like to use will generally (and infuriatingly) have a big black minus sign where the negative lead comes out. Ceramic disk caps are generally not polarized, but most of those aren't the right dimensions or values to be used in place of any of the Game Gear caps. Even when the board symbols aren't present, you can infer the polarity by looking at the the leads and markings of the cap being replaced.

Are you able to take a picture of the portion of the board where you did the parts swap? I'm sure one of us will be able to find the same board to compare and/or contrast as needed.

Sting310

I will take a picture. The cap I am using to replace it with is an Electrolytic Capacitor. It doesn't have the + or - sign.

Does the Majesco version of the GG have bad caps too?

Thanks,

Nick

kendrick

Although the cartridges and the Genesis 3 units issued by Majesco were newly manufactured, most of the Game Gear units were not. Bad capacitors are common to all Game Gears as far as I know.

It's not likely that your electrolytic capacitor is a non-polarized variety, because those are generally huge. Look for a big black line with a lot of minus signs embedded in it, which is how American-manufactured caps are generally labelled.

berzerker1984

when i turn my contrast up on gg it turns the gg off and when i press the start button it does the same.... and plus theres no sound. should i just replace every capacitor?

kendrick

Tim has provided an excellent reference of all the capacitor values and their deduced functions in the link that's provided twice in this thread.

Quote from: kendrick on May 05, 2007, 08:11:28 AM

http://members.optusnet.com.au/eviltim/ggrgb/ggrepair.html


berzerker1984

where can i buy the capacitors from then and what kind of capacitors are they ? i no the numbers of capacitors but what type

beebogates

Quote from: brettlee on February 11, 2009, 07:20:25 PM
Well, yeah. Just bad LCD screen I guess. At least it displays color. LOL
I just got the bigWindow add-on yesterday and I must say, it does help abit. Magnifies the screen to a decent size and blocks out the lights, giving you a nicely luminated screen. I've yet to try different cap values for the display. I'd probly try it out over the weekend and observe the result.

Hey everyone. Coming in really late to the discussion.. this is still relevant to some people after 5 years!
brettlee.. did you ever get to trying out any capacitors of different values? did it work for you?

Hexlo

I have a GG and it has black lines (horizontal) and i want to know how to fix it anything can help