Failed FB2+ Mod - Only Some Carts Work - Atari Flashback Consoles

#1 gnnash OFFLINE

Space Invader

22 posts

Posted Thu Jun 2, 2011 8:42 PM

Well, I finally got around to modding the FB2+ I got from Woot!

Fortunately, after setting my switch to use the internal ROM chip, the original menu works flawlessly! Unfortunately, most of my real carts do not work.

Combat, Home Run and Blackjack are the only carts I have that work. Others, such as Ms Pac Man, Asteroids, Space Invaders, and a bunch others which are said to be compatible do not work. I checked all connections with a meter, all pins are connected to their respective solder pads. I reflowed all of my solder joints, tried again, and still have the same situation.

Any thoughts from anyone? I greatly appreciate any help in advance.

#2 batari OFFLINE

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Posted Thu Jun 2, 2011 11:08 PM

gnnash, on Thu Jun 2, 2011 8:42 PM, said:

Since the 2k games work, the problem sounds like your A11 line is not connected correctly. Perhaps it is loose, or A11 and A12 are swapped?

#3 gnnash OFFLINE

Space Invader

22 posts

Posted Fri Jun 3, 2011 4:03 PM

batari, on Thu Jun 2, 2011 11:08 PM, said:

Since the 2k games work, the problem sounds like your A11 line is not connected correctly. Perhaps it is loose, or A11 and A12 are swapped?

I can check, but having reflowed and checked all joints again, I'm thinking something deeper may be wrong. I heard you had a bad trace on your FB2+, is there a pin on the built-in ROM chip that is connected to the A11 line, which I can jumper my A11 wire to?

#4 batari OFFLINE

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Posted Fri Jun 3, 2011 4:28 PM

Oh, sorry I didn't read it was a FB2+. I should have known from your symptoms, as I had exactly the same issue with mine - A11 is not connected. I was able to fix it by soldering a 30 gauge wire directly to a trace. I posted a picture here:

http://www.atariage....-2/page__st__44

After the fix, I slathered it with hot glue. In case you're wondering, the fix is still holding, even after a friend's toddler got ahold of the FB2+ and yanked it around the house.

#5 gnnash OFFLINE

Space Invader

22 posts

Posted Fri Jun 3, 2011 6:14 PM

Okay, I'll have to try the fix. Is there a pin on the on-board ROM that is connected to this trace? I would much rather solder to one of those pins than to the trace itself.

If I do have to go to the trace directly, I'll probably cover the joint and first half inch of wire in clear nail polish - I've heard it to work great on bad trace repairs. I hope my girlfriend has some lying around...

#6 batari OFFLINE

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Posted Fri Jun 3, 2011 6:52 PM

gnnash, on Fri Jun 3, 2011 6:14 PM, said:

I don't know if it's connected anywhere. You can try scratching a bit of the solder mask off and probing with a multimeter. Another thing that might work is one of those pens with conductive ink. I've used them successfully before but I don't know how long the repair will hold up.

#7 gnnash OFFLINE

Space Invader

22 posts

Posted Fri Jun 3, 2011 9:16 PM

Fixed it! I tried this mod on my old FB2 a couple years ago, and failed when I lifted a trace. Fortunately, I still have the old FB2 around, and found that the A11 pad (pad 20 on the board) is internally connected to the fifth pin from the right on the lower side of the ROM chip.

I soldered the A11 line from the cartridge port to this pin on the ROM chip, and can now play all of my cartridges flawlessly! I greatly prefer this solution to needing to solder directly to a trace.

I'll try to take a picture to help others, it seems that this may very well have been a widespread issue during production of the FB2+ units.

Thanks for your help! I'll try to take pictures tomorrow.

Edited by gnnash, Fri Jun 3, 2011 9:16 PM.