Sega CD Smoke or My Proof of Idiocy

[Nunzio]

So I'm online looking for a power adapter for my Sega CD 1. I come across an auction for an adapter that says it works on NES, SNES and Genesis and I thought 'hey, would my spare NES adapter work?'. Those who know where this is going should laugh now and get it out of their system.

I checked the adapter and the bottom of the Sega CD, noting that the adapter only has 0.1 amps more than the input needed. Fast forward to smoke billowing out of my Sega CD and the adapter plug thrown across the room. As I realize that the Nintendo adapter has AC output.

I blew it. I popped the top off the Sega CD to see the damage and find out that Sherlock Holmes has been in the CD tray the whole time, unbeknownst to me. I took out the PCBs and checked the damage.

http://img402.imageshack.us/img402/5...fucked2tq9.jpg

So that's it. The jumper wire there has melted a little and there is smoke damage.

I really want this Sega CD to work! I can solder and use a DMM and stuff, is this sucker fried or can I save it? It was only exposed to about 3 seconds worth of AC and the power was not on or anything.

Thanks for any help, I really feel like a dumbass.

[TmEE]

take a pic of the other side of the board too... I think there's a dead cap and 7805...

[Nunzio]

Closeups.

http://img168.imageshack.us/img168/9...fucked4no9.jpg

http://img168.imageshack.us/img168/3...fucked5ky8.jpg

http://img177.imageshack.us/img177/2...fucked6nt7.jpg

[TmEE]

there seems to be only fried track on the other side of the board... parts look ok... but you'll never know

[Nunzio]

I cleaned it off with some alcohol on a q-tip. I guess the tracks you mean are the light green things on the circuit board?

I don't even think that the jumper wire melted through the insulation all the way. Just one of the contacts (C23) on the black box that says 200 on it in is pitch black from the melted plastic off the wire.

[TmEE]

Something in that black box is dead... I don't know the purpose of it though (a fuse ?). We need Evildragon he does electronics and has MCD... I've got no experience with MCDs as I don't have one yet.

[evildragon]

Thats one seriously fucked up capacitor..

Well, no offense, but it was foolish what you did. The NES adapter outputs "AC" electrical current, while the Sega CD requires DC.

Putting AC into a DC circuit is deadly for the electronics.

[Nunzio]

You know I started to think it was foolish myself as the smoke was billowing out.

So can I get the parts to fix it or is it just a half a Sega CD worth of spare parts now?

[evildragon]

Wouldn't know, there could be damage to the chips at this point.

If you can, get a replacement board. (the part with the smoke)

This isn't going to garantee there isn't damage to the logic board though. (the one with the CPU, graphics ASIC, BIOS, etc)

[Nunzio]

Aww damn it. Well if anyone wants a wrecked Sega CD I'm the guy to see...

[TmEE]

IF you can't get it working.... I'd be interested in it though

[Epicenter]

Evildragon; he clearly knows AC current is bad for DC electronics, he made that abundantly clear in the OP.. don't rub salt in the wound. I'm sure he feels bad enough. Anyway...

Use an ohmmeter to check continuity between the high side of the power connector and the 7805 regulator's 1st pin (I), Input. If broken find out what component broke the path and replace it or solder over it. If it was a capacitor going to ground, don't solder the DC supply path to ground, that will cause catastrophic damage/ruin your power brick/cause armageddon/etc. Maybe you got lucky and just the power hardware is damaged.. You can always replace those parts.

If there IS continuity to the 7805 and no +5VDC output from pin 3 (O) of the 7805 you need to replace the 7805... and be sure the new one is properly heatsinked.

I recently had a bad power brick burn out the fuse between my MCD's power jack and the 7805. Placing a test clip to fill the gap worked as a temporary solution til I add a new fuse.

[evildragon]

I didn't know he knew it was AC, I misread, I'm only human.

[Dirt Ball Gamer]

You are an evil black dragon who can do no wrongs! Never apologise

[Nunzio]

Thanks epicenter, I'll give it a shot.