Technical and Repair Assistance

[JC]

I think that was like a last breath or something, 'cause it's just got scrambled graphics now.

[133MHz]

Electrolytic capacitors tend to release magic smoke. Also fine circuit board traces in an overcurrent condition. It's pretty rare for chips to fail spectacularly, those like to die in a silent way.
Based on your description (nothing looks charred - scrambled gfx) it seems that the PRG ROM shorted internally and bit the dust. If it's a glop-top cart, then give the board a nice funeral. Are you sure that nothing looks unusual?

[JC]

It's got three globs and nothing looks strange; I've looked at a lot of these globtop boards over the years. I can't tell where the smoke would've come from -- maybe some residue or something? I'd expected to see slight damage/blackening/melting somewhere.

It's a JY Company board...should've been among the better quality pirates. Maybe mine's a fluke.

[133MHz]

Yeah, if there are no external components and no signs of blackening around the traces, the only plausible explanation is gloptop death. Something inside the chip decided to short the voltage to ground causing a very large current to flow through the fragile silicon die, frying it. Localized heating of the protective epoxy and/or board would've produced the smoke.

If there's at least one electrolytic capacitor, that might explain the smoke, but it wouldn't explain the corrupt gfx.

Smell the board, you might be able to identify the offending component just by the stench.

[TheClash603]

  I was having a gamng competition at my house that involved moving a bunch of systems around tonight.  It was pretty frantic and I accidentally plugged my twin famicom into the US outlet on my stepdown converter....

It seems the system will not power up anymore.  I got the light to flash for 1 second and then it shut off.  I am going to try one more time tomorrow, but I am afraid I fried it.

Is there any way to fix this, or do I have to pay anoher $150 for a green fami twin?  I really hope i do not....  x 3999

[133MHz]

Sounds like your AC adapter is faulty, possibly a frayed cord. Do you have a multimeter?

[TheClash603]

No multimeter.  I used the same stepdown converter to play games on my normal famicom and it worked fine.  I am too dismayed to try again tonight, but if it is in fact fried somehow, is there a repair?

[TheClash603]

I read again and you say cord....  I don't know how to check if I have a faulty cord.  I think the normal famicom uses a different cord than the twin.

Do you know of anywhere to get just the cord for the twin famicom if you think it may have been messed up when I plugged in wrong?

[ericj]

I don't think plugging your twin famicom into the US outlet side on a stepdown converter would fry it. I have one and don't use a stepdown converter on it and just plug it right into the wall outlet. The power light on the Twin just flashes for a second when you turn it on anyways; it doesn't stay lit. Try it out tomorrow and I bet you'll see it's fine. If not, check the cord with a multimeter like 133MHz says and if that checks out okay, open up the console and look for a fried voltage regulator, capacitor, or fuse.  Regardless what it is, it will most likely be a cheap and easy repair.

[cosmic-ark]

I think he is talking about a famiclone fc twin not a sharp twin famicom

[ericj]

Is there any way to fix this, or do I have to pay anoher $150 for a green fami twin?  I really hope i do not....

Since he said $150, I assumed he meant Twin Famicom. Who would pay that much for a clone? 

[133MHz]

Also nobody in their right mind would use a 120-100V stepdown converter for a cheapass clone .

[cosmic-ark]

sorry didnt know they came in green

[TheClash603]

Sorry for the delayed response, I have not had a chance to try my twin famicom until today.  Something odd is happening, and it doesn't seem to make any sense electronically at all.

I plugged the system in and turned it on today, and it worked!  So I turned it off and put in another game, and the power light did not come on.  I tried to wiggle the cords and everything, and still nothing.

I didn't do anything for about 5 minutes, unplugged everything and put it back in,and it worked!  Then I turned off the power and turned it right back on again, and no power.

I unplugged the system and tried one more time.  After waiting 5 minutes I plugged it back in and it worked again.  I turned it off and on again, and no power.

Technical people (which I am not in the least), could you please try to explain this to me?  Why does my system need a break between powering up?  This doesn't seem to make sense to me at all, but I tried 3 times and it defintely is what happened.

[133MHz]

Try replacing the 7805, it could've gone haywire. It's an integrated circuit so its logic could be screwed up.