Technical and Repair Assistance

[knux123]

OK guys, the FDS is now working fine...
...though my AV modded Famicom is still acting like an assh*le.

[cubelmariomadness]

I was just playing my power joy on my new lcd tv the other day, and I had never noticed this but there was a weird green line that showed up especially well during solid color screens.


I thought it might just be the tv, but objects can make it disappear, and it flickers occasionally, and it changes colors.

Any ideas on what this is?
Post Merge: September 28, 2010, 05:33:22 pm
anyone?

[133MHz]

Seems like a digital glitch, not caused by the analog video circuits but rather by things like a loose/dirty cartridge connector.
If it happens with the built-in games, it might just be defective. Not surprising considering the relatively low quality of Power Joy systems and the repeated (ab)use during their lifetime.

[cubelmariomadness]

Abuse?

Thanks for telling me. It doesn't bother that me that much, and my power joy is not my main system.

Edit: I got it fixed. I guess some crud got caught in the cart connector, because I blew in it, and now it's glitch free!

[Leufion]

Hi, first post here - pleased to meet you all!

I won a Twin Famicom AN-505 with a replacement belt on Ebay and I was psyched to play some disk games. The seller forgot to include the AC adapter, but thankfully he sent it out and I received it today. It looks pretty thin and cheap since it's a 3rd party one which may have led to the issues I'm facing now. For the record, I did get a step down transformer so I don't damage anything.

After testing a cartridge and disk game separately, they look fine on the screen, but I hear a really loud buzzing noise that overrides almost all sound coming from the game. I notice the control panel in the back of the system is a bit 'loose' and the whole area kind of moves a bit. Not sure if that would have to do with anything tho. I was thinking that maybe it had to do with the AC adapter being cheap and not 1st party.

My second issue is that on Controller 1 the A button doesn't respond. Is there a quick check I can do by unscrewing the controller?
If it is busted, I have a regular Famicom that fried and could use that controller. Would it be compatible with my twin to use the Fami controller?

Thanks guys!

[ericj]

Welcome to the forum!

As for your system, check the mic volume slider on controller #2. That's probably where the buzzing is coming from. It wouldn't be from the AC adapter. You should be able to unplug the controller from a regular Famicom and plug it into the pcb connector on the Twin; they use the same connectors. Otherwise, you can take apart the controller and try cleaning the contacts to see if it will start working again.

[Leufion]

Thanks Eric!

Good news on the controller issue - I opened it up and there was what looked like soot on the A button contact. I used a Q-tip to clean it up and it was working fine for me! Good to know that the Famicom controllers are compatible with the Twin Famicom's pcb connector too.

As for the buzzing issue - I did make sure that the volume slide on the mic is down and I'm still getting it. I'll try to get a video of it.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220670665476&_trksid=p2759.l1259#ht_5460wt_1139
This is the auction where I won it. The very last pic has the AC adapter that was shipped to me.
Post Merge: October 05, 2010, 08:28:25 pm
Here's the video of the buzzing noise:
http://www.youtube.com/watch?v=bxstq9C069Q

Edit: Looks like the controller fix was short lived. The A button would work sporadically and after some more cleaning it went back to not working. Do you think this is a contact or pad issue? It does seem 'light' when pressing A instead of B.

[ericj]

Hmm, any chance you can try another AC adapter to rule it out? Also, maybe try another RCA cable to see if that makes it go away.

You should be able to replace the controller's guts with those from a NES controller, but I'm not 100% on this since the Twin you have has switches on the controllers. It wouldn't hurt to take a look in case it would work.

[Leufion]

Well I think I fixed the controller for good this time. I took the rubber pad from the Famicom controller and transplanted it to the Twin one. I am able to jump in games now.
Hopefully that solves it for good.

As for the AC adapter, I picked up a universal 7.5 v one at Radio Shack today and used the adapter plug that came with the one I was sent to hook into the system, but I got the same buzzing effect. I did try different RCA cables and on a different TV with the same results. I notice that if I unhook the audio AV plug then I won't get the buzzing.
Now I'm thinking maybe it is either the little adapter plug that goes from the end of the AC adapter to the system or possibly the audio out is damaged.

This is what the adapter piece looks like - and I am guessing that since it doesn't fit all the way into the system that maybe that's causing feedback? I may be completely wrong about that. Here's what it looks like once it's on in the back:

[ericj]

Would you be willing to open up the unit and unplug controller #2 from the pcb and see if that makes the audio buzzing go away? You may want to slide that mic volume potentiometer around while the twin is turned on to see if the buzzing gets louder or goes away before you disconnect it.

EDIT: While you have it apart, check the solder joints where the audio plug is grounded to the pcb to see if it's cracked. Also check for any burnt out components or bulging or leaking caps.

[Leufion]

I actually got the buzzing to stop!
I haven't opened the system yet, but I wanted to try cleaning the volume slider in case the microphone was the culprit. I cleaned the board where the volume slider was and made sure it was in the off position. I was able to finally have the buzzing stop which is a huge relief. A few things that I noticed tho - if I even touch the volume slider in the off position it will buzz again - it's extremely sensitive.

Last night when I did open up the system I didn't see anything unusual. In fact the whole inside of the system looked pretty clean to me.

Edit: I did notice in Zelda for disk system that the volume and sound would cut off completely cut off at random even with the mic off. It would come back on sometimes, but not sure if that is related.

[ericj]

I suspected it was the mic on controller #2. Those pots are a real bitch when they get older. The one on my Twin is kind of like that, too. If it starts to buzz, I usually just slide it back and forth a few times and then to "off" and it stops.

Zelda uses the extra FDS sound channels, so it could be related to that. The mic shouldn't make the sound completely cut off, but the interference may affect how your TV picks up on the signal.

[Leufion]

Thanks so much for helping me figure out what it was!

Are there any tips for maintaining the mic or at least getting it to stop freaking out when someone touches it?

[ericj]

I think you can lubricate the pot, maybe with sewing machine oil, nail gun oil , or something similar; someone please correct me if I'm wrong. Otherwise, if it gives you too many problems, just disconnect the damn thing. 

[Leufion]

I was able to swap the slider part out of my old Famicom and put it in the Twin's Controller 2 and it worked out beautifully! I could actually slide it to full volume without any buzz. I'm glad I had that bricked Famicom for spare parts.