Skip navigation
Welcome, Guest! Please Login or Join

Loading...

Tech Talk NES repair - faulty controller port

Sep 07 at 6:07:45 PM
Lincoln (133)
avatar
(Frank W. Doom) < Bowser >
Posts: 5572 - Joined: 12/19/2008
California
Profile
I have a NES that has issues with the player 1 controller. It registers no button presses, everything pressed at once, or sometimes normally. player 2 works fine.

Any idea what the issue is or what needs to be replaced/repaired to make it work?

-------------------------
ebay auctionsrunning FS thread famiROM updates and download thread for .nes info and splitting

Sep 07 at 6:19:07 PM
Abelardo (75)
avatar
(Abelardo González) < El Ripper >
Posts: 1232 - Joined: 10/26/2011
Mexico
Profile
Inspect the connections from the contoller port to the NES PCB, look for faulty connections, shorts, cold or cracked solder joints, etc. Another thing you can do is switch player 1 & 2 ports to see if the fault is in the port itself or is further down the NES PCB.

Sep 07 at 7:13:33 PM
Mobiusstriptech (10)
avatar
< Eggplant Wizard >
Posts: 273 - Joined: 12/23/2016
Ohio
Profile
Usually I see people have pinched the wires internally and broken them. It's pretty common because the wires fit very nicely over one of the screw posts.

-------------------------
For mod work and questions email us at mobiusstriptech@gmail.com

Twitter: @mobiusstriptech

Youtube: MobiusStripTech

Website: http://www.mobiusstriptechnologie...

Sep 07 at 7:17:49 PM
Mega Mario Man (58)
avatar
(Tim ) < Kraid Killer >
Posts: 2251 - Joined: 02/13/2014
Nebraska
Profile
I would start by swapping the the P1 and P2 controller port cables on the NES board. Now, see if you have the issue, only opposite. If the P1 port now works and the P2 port doesn't, you have some sort of issue on the board. Then I would check for bad solder joints or traces coming for the pins on the board. If P2 port still works and the P1 port still doesn't work after the swap, then you have issues with either the wiring harness or the port itself.

If it is the wiring harness or the port, you need to ohm out each run on the controller port. Do this by touching the pin on the front with one lead and touching the matching pin on the wiring harness with the other lead. After you find the bad run or runs, then you must narrow it down to the wire or the pin in the port by ohming out just the pin in the port and then just the wire.

Hope that was clear! Good luck.

-------------------------
Current Project
Isometric Survival Horror

Older Projects
Tailgate Party, Power Pad Demo, Happy Hour

Links
Store, Facebook, Twitter

Sep 08 at 12:23:50 PM
SUBSCRIBER
darkchylde28 (8)
avatar
(Doug ) < El Ripper >
Posts: 1027 - Joined: 01/12/2016
Tennessee
Profile
Originally posted by: Mega Mario Man

I would start by swapping the the P1 and P2 controller port cables on the NES board. Now, see if you have the issue, only opposite. If the P1 port now works and the P2 port doesn't, you have some sort of issue on the board. Then I would check for bad solder joints or traces coming for the pins on the board. If P2 port still works and the P1 port still doesn't work after the swap, then you have issues with either the wiring harness or the port itself.

If it is the wiring harness or the port, you need to ohm out each run on the controller port. Do this by touching the pin on the front with one lead and touching the matching pin on the wiring harness with the other lead. After you find the bad run or runs, then you must narrow it down to the wire or the pin in the port by ohming out just the pin in the port and then just the wire.

Hope that was clear! Good luck.

If you swap how the ports connect to the board, and the port which is bad changes, wouldn't that indicate that it's the port, and not the board itself?  Plugging a new port into the main board's in/out for "Player 1" and suddenly having port 1 work would indicate the port was bad.  Am I missing something here?  I've not run into this issue personally and was interested in your reply and troubleshooting, but don't understand the thought process behind it being the system/main board if switching which physical controller port is connected to "Player 1" on the main board resolves the issue (and recreates the same issue for "Player 2" as a result).

-------------------------
Need Stadium Events + Panesian titles, 6-in-1's, Menace Beach, Moon Ranger & Secret Scout to complete my licensed/unlicensed sets.

If you've got any of the above for sale, hit me up!

Sep 08 at 12:55:20 PM
Mega Mario Man (58)
avatar
(Tim ) < Kraid Killer >
Posts: 2251 - Joined: 02/13/2014
Nebraska
Profile
Originally posted by: darkchylde28
 
Originally posted by: Mega Mario Man

I would start by swapping the the P1 and P2 controller port cables on the NES board. Now, see if you have the issue, only opposite. If the P1 port now works and the P2 port doesn't, you have some sort of issue on the board. Then I would check for bad solder joints or traces coming for the pins on the board. If P2 port still works and the P1 port still doesn't work after the swap, then you have issues with either the wiring harness or the port itself.

If it is the wiring harness or the port, you need to ohm out each run on the controller port. Do this by touching the pin on the front with one lead and touching the matching pin on the wiring harness with the other lead. After you find the bad run or runs, then you must narrow it down to the wire or the pin in the port by ohming out just the pin in the port and then just the wire.

Hope that was clear! Good luck.

If you swap how the ports connect to the board, and the port which is bad changes, wouldn't that indicate that it's the port, and not the board itself?  Plugging a new port into the main board's in/out for "Player 1" and suddenly having port 1 work would indicate the port was bad.  Am I missing something here?  I've not run into this issue personally and was interested in your reply and troubleshooting, but don't understand the thought process behind it being the system/main board if switching which physical controller port is connected to "Player 1" on the main board resolves the issue (and recreates the same issue for "Player 2" as a result).

I think you are misunderstanding what I am saying. I reread what I wrote and it all appears to be in order. When I say "swap", I mean plug Player 1 Port into the Player 2 Board Spot and vice Versa. Essentially making Port 1 = Player 2 and Port 2 = Player 1. I'm not changing out any parts, just simply moving the existing port wires on the board.

Normal Hookup
Port 1   -BAD-     Board 1 (Port 1 is Player 1)
Port 2   -GOOD -  Board 2 (Port 2 is Player 2) (Known working port and board)

Swapped
Port 1   -GOOD-     Board 2 (Port 1 is now player 2) (Since we know board 2 works, Port 1 must work)
Port 2   -BAD -    Board 1 (Port 2 is now Player 1) (Since we know that Port 2 works, Board 1 must be bad)
 

-------------------------
Current Project
Isometric Survival Horror

Older Projects
Tailgate Party, Power Pad Demo, Happy Hour

Links
Store, Facebook, Twitter

Sep 08 at 1:01:14 PM
Lincoln (133)
avatar
(Frank W. Doom) < Bowser >
Posts: 5572 - Joined: 12/19/2008
California
Profile
these are all great suggestions. i'm gonna dig into it this weekend.

-------------------------
ebay auctionsrunning FS thread famiROM updates and download thread for .nes info and splitting

Sep 08 at 1:48:18 PM
SUBSCRIBER
darkchylde28 (8)
avatar
(Doug ) < El Ripper >
Posts: 1027 - Joined: 01/12/2016
Tennessee
Profile
Originally posted by: Mega Mario Man
 
Originally posted by: darkchylde28
 
Originally posted by: Mega Mario Man

I would start by swapping the the P1 and P2 controller port cables on the NES board. Now, see if you have the issue, only opposite. If the P1 port now works and the P2 port doesn't, you have some sort of issue on the board. Then I would check for bad solder joints or traces coming for the pins on the board. If P2 port still works and the P1 port still doesn't work after the swap, then you have issues with either the wiring harness or the port itself.

If it is the wiring harness or the port, you need to ohm out each run on the controller port. Do this by touching the pin on the front with one lead and touching the matching pin on the wiring harness with the other lead. After you find the bad run or runs, then you must narrow it down to the wire or the pin in the port by ohming out just the pin in the port and then just the wire.

Hope that was clear! Good luck.

If you swap how the ports connect to the board, and the port which is bad changes, wouldn't that indicate that it's the port, and not the board itself?  Plugging a new port into the main board's in/out for "Player 1" and suddenly having port 1 work would indicate the port was bad.  Am I missing something here?  I've not run into this issue personally and was interested in your reply and troubleshooting, but don't understand the thought process behind it being the system/main board if switching which physical controller port is connected to "Player 1" on the main board resolves the issue (and recreates the same issue for "Player 2" as a result).

I think you are misunderstanding what I am saying. I reread what I wrote and it all appears to be in order. When I say "swap", I mean plug Player 1 Port into the Player 2 Board Spot and vice Versa. Essentially making Port 1 = Player 2 and Port 2 = Player 1. I'm not changing out any parts, just simply moving the existing port wires on the board.

Normal Hookup
Port 1   -BAD-     Board 1 (Port 1 is Player 1)
Port 2   -GOOD -  Board 2 (Port 2 is Player 2) (Known working port and board)

Swapped
Port 1   -GOOD-     Board 2 (Port 1 is now player 2) (Since we know board 2 works, Port 1 must work)
Port 2   -BAD -    Board 1 (Port 2 is now Player 1) (Since we know that Port 2 works, Board 1 must be bad)
 

I really do apologize, but to me, at least, your explanation is still incorrect, even though I understand what you're saying now.

I worked it out on a spreadsheet and it would still seem to be that the PORT would be bad, not the BOARD.  If the starting point is Player 1 is bad and Player 2 is good, the opposite would be Player 1 is good and Player 2 is bad.  See below.
 
Player 1 Good? Player 2 Good?
       
Port 1 ? Port 2 Yes!
Board 1 ? Board 2 Yes!
       
Port 2 Yes Port 1  
Board 1   Board 2 Yes

In swapping the ports to new boards, you reassign which is player 1.  So, in the beginning, we know that both port 2 and board 2 are correct, but have no way of knowing whether port 1 or board 1 are any good.  Once the swap is done, we know that board 2 (which is still player 2) is good, so if player 2 is bad, it's port 1 that's caused it.  Similarly, if plugging port 2, which is known to be good, into board 1 results in a working controller, then board 1 can be verified as working.  The logic is still there, the explanation just came out swapped, as the boards will always result in being whichever player they're originally assigned to, but the ports can be swapped.

Edit while still posting:  I believe I see the small issue with your original post.  You simply refer to P1 and P2, which could mean either Player 1 and Player 2 or Port 1 and Port 2; the Players can't be swapped (boards are static for each player), but the ports can be.  So, if you swap the ports and get the same result, it's board 1; if you swap the ports and get the opposite result, it's port 1.  And, unmentioned, but if you do the swap and both go out, it's both board 1 & port 1.

Let me know if I'm off here, but gridding it out locked me in on thinking you'd accidentally gotten it backwards when typing (putting down opposite instead of same).  Thanks again for the lesson & discussion!

-------------------------
Need Stadium Events + Panesian titles, 6-in-1's, Menace Beach, Moon Ranger & Secret Scout to complete my licensed/unlicensed sets.

If you've got any of the above for sale, hit me up!

Sep 08 at 1:53:12 PM
Mega Mario Man (58)
avatar
(Tim ) < Kraid Killer >
Posts: 2251 - Joined: 02/13/2014
Nebraska
Profile
I think we said the same thing... I am never talking about the characters on the screen. It's all simply hard ware.

-------------------------
Current Project
Isometric Survival Horror

Older Projects
Tailgate Party, Power Pad Demo, Happy Hour

Links
Store, Facebook, Twitter

Sep 08 at 2:06:29 PM
Mega Mario Man (58)
avatar
(Tim ) < Kraid Killer >
Posts: 2251 - Joined: 02/13/2014
Nebraska
Profile
Originally posted by: Lincoln

these are all great suggestions. i'm gonna dig into it this weekend.

Awesome. Please update us, I'd love to hear what you find out. Also, I may be able to send you some parts if needed. I have a few shells lying around that had dead NES boards in them.
 

-------------------------
Current Project
Isometric Survival Horror

Older Projects
Tailgate Party, Power Pad Demo, Happy Hour

Links
Store, Facebook, Twitter

Sep 11 at 1:50:51 AM
Lincoln (133)
avatar
(Frank W. Doom) < Bowser >
Posts: 5572 - Joined: 12/19/2008
California
Profile
i swapped the port wiring and the port on the p1 connection is still not working. so that suggests some component on the board after the wire connector is faulty. there's a series of ceramic caps right after the connector and them some other components I'm not familiar with. I'll try to get some pics for reference.

-------------------------
ebay auctionsrunning FS thread famiROM updates and download thread for .nes info and splitting

Sep 11 at 2:56:09 AM
Pikkon (6)
avatar
(スーパーファミコンコレクター ) < Meka Chicken >
Posts: 740 - Joined: 10/17/2010
Florida
Profile
Just like the snes if the cpu is messed up it can cause the controller not to work but could be something else as well,here's some info.

https://assemblergames.com/thread...
https://assemblergames.com/thread...
https://assemblergames.com/thread...

-------------------------


Sep 11 at 2:31:29 PM
Nesmaniac (1)
avatar
(Matthew Sizemore) < Crack Trooper >
Posts: 198 - Joined: 12/14/2010
Kentucky
Profile
Strange. I've had probably a hundred front loaders that's I've tested and never once have I had an issue with a controller port. Very good suggestions here & sad to see it's apparently something on the motherboard. Start by checking to see that 5volts is coming in & just as important make sure the ground is good. I'm sure it's still something simple tracing it down is the problem of course.

-------------------------
 

Sep 11 at 4:17:20 PM
Mega Mario Man (58)
avatar
(Tim ) < Kraid Killer >
Posts: 2251 - Joined: 02/13/2014
Nebraska
Profile
Originally posted by: Nesmaniac

Strange. I've had probably a hundred front loaders that's I've tested and never once have I had an issue with a controller port. Very good suggestions here & sad to see it's apparently something on the motherboard. Start by checking to see that 5volts is coming in & just as important make sure the ground is good. I'm sure it's still something simple tracing it down is the problem of course.
Yup, this is a good idea. Now time to see if you have proper voltage at the connection on the board. I'm going to venture to guess that those little tiny caps are fine. Those things almost never go bad unless something else failed and blew it. Their main function is to protect against shorts (from what I understand).

After this, I'm pretty much useless. I'm sure someone much smarter than me can chime in.

 

-------------------------
Current Project
Isometric Survival Horror

Older Projects
Tailgate Party, Power Pad Demo, Happy Hour

Links
Store, Facebook, Twitter

Sep 13 at 1:11:45 AM
Memblers (3)
avatar
(Joey Parsell) < Eggplant Wizard >
Posts: 234 - Joined: 05/12/2008
Indiana
Profile
If it's not the CPU or failed cap or something else really dumb, it could be the 40H368 chip on there. It used as a buffer, sitting between the CPU and controller port.

-------------------------
 


Edited: 09/13/2017 at 01:12 AM by Memblers

Sep 13 at 4:20:06 PM
Lincoln (133)
avatar
(Frank W. Doom) < Bowser >
Posts: 5572 - Joined: 12/19/2008
California
Profile
Originally posted by: Pikkon

Just like the snes if the cpu is messed up it can cause the controller not to work but could be something else as well,here's some info.

https://assemblergames.com/threads/nes-motherboard-with-a-st...
https://assemblergames.com/threads/nes-controller-ports-not-...
https://assemblergames.com/threads/deffective-nes-controller...


these are great links, thanks!

I borrowed a couple images out of there for reference.

 

in the photo, the white connector on the bottom is the p1 controller, the white connector on the left is the p2 controller.

I don't have a proper scope to really see what's going on with various signals so I'll have to do what I can with a basic voltage and continuity checks (which I still have to do). The low voltage situation is interesting but I'm considering that unlikely right now due to one port working fine and the other not.  I don't have a good enough handle on electrical engineering to understand what the diodes (da1-da4) are doing for the controllers- sounds like some kind of protection circuit? My instinct is that 368 buffer (u7) has failed- that's the kind of thing I was anticipating going into this not knowing the circuit. I can swap u7 and u8 pretty easy just to verify. 

 

-------------------------
ebay auctionsrunning FS thread famiROM updates and download thread for .nes info and splitting


Edited: 09/13/2017 at 04:22 PM by Lincoln

Sep 25 at 2:02:52 PM
Lincoln (133)
avatar
(Frank W. Doom) < Bowser >
Posts: 5572 - Joined: 12/19/2008
California
Profile
I pulled the p1 and p2 buffer chips and put the known working p2 chip in the p1 circuit. No change unfortunately, and I managed to pull up a trace removing the p1 chip :\ That was an easy patch but I didn't accomplish much for the effort. 

I hadn't really looked things over before getting a handle on the circuit. I spotted this while tearing down to pull the chips.



The p1 buffer chip (U7) is to the immediate left of that dark patch (front edge of the board is at the top). That seemed like it might be the culprit but I did a continuity check across each of those traces and they all came up ok. I'm still not confident in them but I'm leaving them alone for now. I didn't consider it at the time but I should check for corrosion elsewhere along the controller circuit. The board is kinda rough like this overall. 

Anyway. I'm not sure what to do next. Pull the diode arrays from p2 and swap them into the p1 circuit? Patch the traces around that dark spot? Something else I'm missing?

-------------------------
ebay auctionsrunning FS thread famiROM updates and download thread for .nes info and splitting


Edited: 09/25/2017 at 02:04 PM by Lincoln

Oct 02 at 3:22:03 PM
Nesmaniac (1)
avatar
(Matthew Sizemore) < Crack Trooper >
Posts: 198 - Joined: 12/14/2010
Kentucky
Profile
I recommend taking some rubbing alcohol and a toothbrush and scrubbing all around the board & then use metal polishing paste to go over all the really bad looking parts with a brush. Then use a brush and alcohol to clean off the board again. Then let your soldering iron get good and hot & start heating up the bad looking solder points probably adding a little solder too. I had a game boy game no working and I simply cleaned the board and reheated all the little solder points around all the chips and it works great again. It's a solder point issue I bet just by looking at the picture of the board. I saw a guy on youtube fix a NES with redoing solder points that looks like those on yours.

-------------------------
 


Edited: 10/02/2017 at 03:22 PM by Nesmaniac

Oct 02 at 4:18:35 PM
Mega Mario Man (58)
avatar
(Tim ) < Kraid Killer >
Posts: 2251 - Joined: 02/13/2014
Nebraska
Profile
I have a board where it looks like that (a lot worse though) around where the power\rf box connects to the board. The board gets now power, I successfully temp jumped a couple of wires over the bad traces and got it working. After I made the fix permanent, it stopped working again.   I have not gotten the board to work again after that. I guess what I am getting at is that could be the issue.

-------------------------
Current Project
Isometric Survival Horror

Older Projects
Tailgate Party, Power Pad Demo, Happy Hour

Links
Store, Facebook, Twitter