Taking my Duo out of storage

[ProfessorProfessorson]

If you have a dishwasher I'd recommend desoldering the supercap and running the pcb through a good wash, then let it air dry for a couple of days before you do the new caps.

[MNKyDeth]

Well, I don't own a dishwasher but I have a fiberglass scratch brush and I have some cleaner that is safe for PCB and plastic, quick drying no residue. It is a contact cleaner and the board looks good before I started soldering.

I did just under half of the board already. Needed a break as I am starting to go a bit cross eyed looking at these small ceramic caps and trying to tin them and the pads before placing them down.

Unfortunately I did drop one and I just cannot seem to find it so I may need to order some more by the time I am done.

I am using GameTechUS method of removing caps, by snipping them. So far no pulled or missing pads and my soldering looks adequate, not perfect but not real messy either. After the first two imo they became really nice so I went back and touched up the first two I did after I got the technique down.

The worst one I ran into so far was the 3.3uF 50v that sits just behind the cd-rom connectors. I thought the board was eaten away but after using my scratch brush on it, it showed me that the pads were still there. It was just a ton of crap around and on the pads hiding them until it was cleaned.

The audio section I can see almost every SMT cap is corroded so that area might be the worst spot yet. I just havn't got there yet.

[mickcris]

I find that grabbing them with pliers and twisting them works pretty well.  I think most people rip the pads up when the do the rock back and forth method.  usually when you twist them, the top comes off of the leads, then you can break off the black plastic piece and desolder each leg.

[MNKyDeth]

The method I am doing mickcris... I think is safer than rocking or twisting. All I did was cut the cap close to it's base and all it leaves behind is usually some black material and the two legs from the cap. Then I just go over the pads with my iron to clean the legs off and then re-tin them.

However, the thru-hole caps I messed one up so far. There are three rather large blue caps. I was de-soldering from the back side of the board and slowly pulling the cap out. Since they sit so close I couldn't see that I was pulling one of the traces right out of the board.

So... I actually have the wire trace visible and still connected at the next point so I will need to run a wire to that location. The one I messed up is the one right behind the power switch on my Duo. I am a bit nervous about the other two now back in the audio section as I still need to pull them out.

If there are any tips for getting these large blue ones out before I get to them it would be appreciated. They scare me now.

[mickcris]

I have a Hakko 808 which works great.  This tool will work too as you probably dont want to spend the money on that:
http://www.radioshack.com/radioshack-45-watt-desoldering-iron/6402060.html

I have done 4 Duos and 2 TEs and have only had 2 pads pull off the board using the twist method.  They probably would have pulled off no matter what method I used though.   I'm sure your method works too, just seems to me that it would take more effort with pieces possibly flying everywhere.

[CPTBadAss]

I always had trouble with the radio Shack bulb. Not that it's bad. Probably user error. I find that if the 808 isn't the right tool for desoldering something, I reach for an Edsyn Soldapullt. It's about $20.

[MNKyDeth]

Actually I did do a bit of shopping at RadioShack.  They are doing their 20-30% off everything right now before they close the store here since they are going out of business.

I do have a solder sucker, but it is a manual one. I realized by looking at the other large thru-hole caps the wires were a little thicker than the small ones.

So this time I when I sucked the solder out the little that remained I was able to slightly bend then cut the backside of the wires and pull the caps out very carefully without any further issues.
The first one must have had to much force when I was pulling on it so now I pay the price on that one. I am pretty sure I can fix it and then continue on with getting the rest of these caps on the board.

Thanks for the input though it did give me some ideas to try to better remove these.

[MNKyDeth]

Ok, full cap replacement is done. I went out to test the machine and oh shit yeah... The Duo turned on.

I tested Cadash for the HuCard and my low volume audio is fixed and the HuCard worked without issue. I played for about 15min and seems good. I used to have to turn the audio up to about 50 on my tv and now I only need it at 15. Both of my controllers also seemed to work properly now. My auto-fires seemed to work right instead of before being intermittent.

However, I still do have one problem. The cd-rom before I did the cap replacement had issues reading discs. It would read my Dungeon Explorer 2 disc but not my 3 in 1 disc that came with my Duo. Now it won't read any discs. I tried a few different ones to make sure. It spins up like before, tries to read the discs but never actually reads them. I let it sit for about 10min to make sure.

Do I need to adjust the pots for the unit or do I need to replace the HOP-M3? I have only done the caps so far. I don't want to start adjusting the pots and mess it up further.

Edit:

I am gonna add some pics once I get them uploaded.

[MNKyDeth]

Just updating my thread/post again.

I really didn't want to mess with the pots for the cd part of the unit but I marked them and decided to at least try. In the end I had to adjust VR102 and VR103 just a small amount. I didn't touch the others and I don't have an oscilloscope to find the exact proper settings. But....

I just successfully listened to an entire audio cd, played the intro to about 5-6 games and completed level 1-1 on Buster Bros without any issues that I could tell. I also played the intro to Lords of Thunder and all of it's audio tracks in the menu.

I am extremely excited and happy I have accomplished this repair to my Duo. I honestly couldn't have done it or even known where to begin to fix my Duo without this forum and the GameTechUS vids.

I will be adding pics to this thread with pictures of my Duo. I just want to show what I have done, the one cap I messed up, before and after shots etc. They will be in the first post, I will edit them in.

[schweaty]

congrats, dude.  it must be a very satisfying feeling. 

[Necromancer]

Congrats on getting it up and running again. 

[CPTBadAss]

Thanks for sharing the repair log with us .

[MNKyDeth]

Well, the next thing I am doing to my Duo is RGB to component. Using the V2 chip from http://www.tg16pcemods.com/new-and-improved-rgb-to-component-converter.html

I ordered it last week and it is shipped. Hopefully be here in the next couple days. I think I am going to set it up with a 8pin mini-Din port. That way I can reuse the connection later down the road if I decide to go full on RGB.

I will then make a cable from the 8pin Din port to a scart cable as that is what the XRGB seems to use. http://www.amazon.com/DP3913515-Framemeister-Micomsoft-Upscaler-Import/dp/B006H39XJS

I know I could buy a cable but I love learning how to do this stuff as well. I am familiar with crimping cables already so it's just a matter of having the pieces I need.

Not sure if I will add that mod to this thread or start a new one yet. I just want to do this console right and make it last another 20-40yrs or until I die I suppose.

[Dicer]

That Duo is gettin some serious lovin, keep up the good work...

[MotherGunner]

Nice read, thanks for sharing!