Found cause of vertical collapse on 20EZ, where to go from here?

Segagee

New member
Joined
Feb 27, 2009
Messages
337
Reaction score
2
Location
South Carolina
Found cause of vertical collapse on 20EZ, where to go from here?

Posted about a cap kit gone wrong a few weeks ago on my Sanyo 20EZ, turned it on to get a nice centered white line staring me in the face. Cables, switches, pots, and everything seemed to be fine. Got around to removing the board tonight again, and to my dismay found a pretty scorched up C408 pad/trace. To my knowledge a bad cap at this location can cause a vertical failure, so I have a few questions as where I should go from here.

1. I tried soldering a new cap at C408 a few times before reporting here, but keep coming up with cold joints. This was also occurring when I attempted to install the cap kit. This is the only cap location I have had this problem with, is it because the board is burnt at this location? I'm holding off on trying again because I do not want to scorch the board anymore.

2. If simply soldering a new cap is out of the question, I'm thinking this may have to be repaired (if "repairing" is possible) with either jumper/trace wires, so any tidbits on this subject would be of help.

3. Is it safe/smart to test the monitor outside of the cabinet?

3. See pics, and thanks for any and all input.
 

Attachments

  • c4081.jpg
    c4081.jpg
    36.9 KB · Views: 73
  • c4082.jpg
    c4082.jpg
    33.5 KB · Views: 72
You need to scrape that old flux and junk of the pads with a small flathead screwdriver/knife or similar, be careful though. It looks like the pads are actually gone but they are probably under all that junk. Try taking a small wire brush to it. After it's cleaned up try using flux on the exposed copper traces and then try resoldering A new cap in there.

This may be because you are using rosin core solder. Try cleaning it up and trying again.
 
Also, It should be safe to test the monitor out of the cab just DO NOT! plug it in to a regular wall outlet. Use the one thats in the cab, that is @ 100 V and as you know regular wall outlets are @ 120V.
 
If the pads are gone, you can typically silicone the cap in place, and either run the legs to the nearest good pad, or run a wire trace to the next pad in the circuit.
 
Thanks for the help and ideas, this seems to be a somewhat common problem so it's good to know i'm not up shit creek without a paddle just yet. I'm assuming it is possible to solder the cap legs directly to their respective traces instead of using wire to jump to a nearby pad? Also must I remove the green material or is it ok to solder directly to that? This just seems easier than wire jumping, but correct me if I am wrong.

Excuse my awesome MS Paint skills but I drew up a little diagram to make sure I am aware of which trace goes to which leg before I start roasting things with my iron and scraping off unnecessary traces. Hopefully it makes some sort of sense.
 

Attachments

  • traces.jpg
    traces.jpg
    37.2 KB · Views: 52
That looks like excess flux residue from soldering. I use a small exacto knife to chip it off and then hit it with a fiberglass pencil to make the pads like new again. If the pads are gone you can simply bend the leads over to where the trace goes. Yes you have to scrape off the green solder mask where you want to solder to. Again, I use a small exacto and fiberglass pencil.
 
just remember to run the power for the monitor thru an isolation transformer. the outlet in the bottom of the cab is NOT the place to plug the monitor in. get yourself (or make one) a monitor discharge tool so you dont shock yourself real bad. remember to touch both sides of the fuse in case the fuse is blown, cause the charge may still be there and bite you, and its gonna hurt. earth ground the monitor frame. you might want to build a test rig if you are planning to do more testing on monitors, PCB's and game boards.
 
just remember to run the power for the monitor thru an isolation transformer. the outlet in the bottom of the cab is NOT the place to plug the monitor in.

Disregard the above information, it is incorrect for this application. The two outlets in the bottom of a Nintendo cab are both 100vac, and you can plug your Sanyo 20EZV into either one. Both outlets are also fed from the isolation transformer in the bottom of the cab.
 
Thanks for the help and ideas, this seems to be a somewhat common problem so it's good to know i'm not up shit creek without a paddle just yet. I'm assuming it is possible to solder the cap legs directly to their respective traces instead of using wire to jump to a nearby pad? Also must I remove the green material or is it ok to solder directly to that? This just seems easier than wire jumping, but correct me if I am wrong.

The green material is called 'solder mask' and yes, you must remove it - it's non-conductive. Just CAREFULLY scrape off a section and you'll be able to solder on to it.

I would first see if I could clean up the pads, however. It's hard to tell if the pads are gone due to the large amount of junk in the vicinity. Try scraping off all the junk and see if the pads are still there before you try soldering to the traces.
 
I like to take some solder wik and use the tip of my soldering iron to gently scrape away flux build up like that. I would bet the pads underneath are ok you just need to clean them.
 
... I tried soldering a new cap at C408 a few times before reporting here, but keep coming up with cold joints. This was also occurring when I attempted to install the cap kit...

The main causes of cold joints are...
1) Moving the component as the solder is cooling.
2) Inadequate heating of the parts to be soldered. You must apply the tip of the iron to the pad and component leg at the same time, then feed solder to the other side of the joint and it will flow where the heat is.
3) Dirty pads (but the flux in the solder should clean them , that's what it's there for). If you're putting the solder on the iron before you bring it to the joint then the flux will all burn off before you get there and you'll get a crappy connection.
 
Finally got around to cleaning up the pads and soldering a new cap in today, but am still getting the same result, vertical collapse. I have not tried soldering the cap legs to the actual traces on the board yet. Should I try this next or solder the cap legs at C408 to another pad?

On another note, there is no "beep" sound when I boot up the monitor, and the game itself makes no coin up noise. Not sure if this is related to the monitor issue or what, but everything seems to be wired up correctly.
 
If you have the chasis out take a picture and post it up. There may be another issue and not that particular cap. Have you checked for continuity from the cap legs to the next point along the same trace?
 
On another note, there is no "beep" sound when I boot up the monitor, and the game itself makes no coin up noise. Not sure if this is related to the monitor issue or what, but everything seems to be wired up correctly.

Yeah..thats pretty important if the game isn't booting.
 
not trying to derail your topic here, but I had a similar problem on a WG D9200 neck I was replacing transistors on. the middle solder pad for the green transistor was fried, and I actually jumpered the middle transistor leg to the next circuit point and it worked. I DID NOT try scraping in that area or scraping off some solder mask (ideally I would've liked to bend the leg L-shaped against the trace and solder from there) ... any longterm effects of keeping it jumpered, or is it a situation of "it works now, leave it alone" ?

either I have useless information to offer with said hack, or I'm an idiot. you decide. :)

I'll be reading up on 20EZ topics more now... given that I'm the new owner of gatordad's Popeye. :)

(needs a recap)
 
Nah.. It'll be fine. The only thing you have to make sure of when doing a repair like that is that you connect the right trace point. LOL
 
Nah.. It'll be fine. The only thing you have to make sure of when doing a repair like that is that you connect the right trace point. LOL

we'll find out, when the screen goes purple again.

or doesn't work at all.

creepy part about those old 9200 necks is they get uber hot and can actually reflow solder themselves. anyone know of a cooling apparatus I can rig together for that?

guess I could make like a big metal plate spanning both sides of the monitor frame, and cut a hole in the middle for a fan, put grills on it and everything. :eek:
 
Back
Top Bottom