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/img402/5941/segacdfucked2tq9.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/img168/9404/segacdfucked4no9.jpg

http://img168.imageshack.us/img168/3700/segacdfucked5ky8.jpg

http://img177.imageshack.us/img177/2234/segacdfucked6nt7.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.

http://img220.imageshack.us/img220/1083/segacdfucked7jm1.jpg

[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.

[Devon]

hello i joined to stalk this thread, this weekend on ebay i found a sega cd model one, it was close to me so the guy closed the auction i paid and picked it up. the sega adapter wasn't there and in the box was a nintendo one, i tryed asking the guy for a sega he looked and couldn't find it. my stupid know it all friend was like its 1.3a so it will work because he wanted to get out of there, i plugged it in and of course it fried. i searched and ran into this thread and noticed mine was fried in the same spot as yours and lo and behold when i took it apart there was sherlock holmes in the unit... so iam wondering if by a strock of madness maybe you got rid of yours and i ended up wiht the same broken unit? on the other hand i want a sega cd really bad so if that part is availiable the power board i would love to replace it.

[Nunzio]

Ahh, reliving my smartest moments.

That is creepy as hell that the same thing happened to you... especially with Sherlock Holmes in the CD tray. I can honestly say however that the murdered Sega CD is still in my closet and the copy of Sherlock Holmes in now in a CD wallet with my other Sega CD games.

And there is basically no way to fix it. Just wait to find another one like I did :P And then don't kill it!

[Devon]

okay glad its not your same unit, as my friend started cracking up when i showed him the thread, i should have punched him in the gut for ruining my sega cd.....

[Xeniczone]

What do you mean 'no way to fix it'? Where you unable to replace the regulator and compactor?

[Nunzio]

It's not reasonable to get the parts to replace that one board I meant. Also, as mentioned earlier in this thread there is no guarantee that the rest of it isn't damaged.

I was never able to identify the 'black box' that bought it. Some kind of fuse or capacitor. Anyways, I'm no electronic genius either so that never was much of an option. I suppose he could replace it if he was more able and willing then I was :P

[kool kitty89]

I thought the fuses in the Sega CD were there to prevent damage from cases like this, reversed polarity, or power surges... Unlike the MD1 which has no fuse or diode protection. MD2 has a diode iirc)

[dodgeme]

Still that at least looks somewhat fixable. You should have seen the SEGA CD that I got before. The board was so corroded it looked as though someone dunked it under water about 10 years ago and then never bothered to dry it and left it in a moist basement. The small attempts at trying to fix it revealed that the corrosion at away at the video chip pins so I gave up. It still sits under my bed to this day, it is a model 2 lol. Now I got a Model 1 that works great. I am glad I haven't managed to screw adapters up yet but with all that I have I am surprised I haven't.

[Roussimoff]

Hmmm....not really sure, not much of a "tech" person myself, though I have experienced similar. Years ago my nephew left my Atari Jaguar on all night after he fell asleep, and I awoke to a burning smell and the system no longer worked at all. Also, the port where the AC adapter plugs in was blackened...

Best of luck!
:)

A.R.

[kool kitty89]

Hmmm....not really sure, not much of a "tech" person myself, though I have experienced similar. Years ago my nephew left my Atari Jaguar on all night after he fell asleep, and I awoke to a burning smell and the system no longer worked at all. Also, the port where the AC adapter plugs in was blackened...

Best of luck!
:)

A.R.

That's really weird... sounds like a power surge and/or the power supply going bad.
You should be able to leave those systems on indefinitely under normal operating conditions.

[Roussimoff]

Well, he may have "done" something as well and was either afraid or ashamed to tell me...he was a rather destructive little brat ten years ago..lol... (And little has changed! :p)

[Xeniczone]

@Nunzio; Do you or Devon still have the supposed board. Which is damaged. I have an extra Model 1 Sega CD that I could play with that board and see if I can get it to work. Maybe write a tutorial on how to fix this common problem. It seems to be rather common for people to use NES adapters. I would break it myself, but Model 1s are rather hard to come by these days, and I don't have a Nintendo.

[Nunzio]

Yeah I still have it. I'm going to hook it up and give it a test first. I can't remember if I ever actually tried after getting the right adapter.

[Xeniczone]

I would be happy to pay you for it, or send it back for the price of parts to repair, not to diagnose.

[CelticRedemption]

Heya, Is this still active? I recently bought a SEGA Mega CD from the UK that was labeled as faulty. I tried fixing it but no success, when i replaced the fuse that was apparantly blown, I came across the same problem as 2 others here have also been met with, that black box had one of its pins look as if it has exploded or something, lol. Has anyone identified what that black box with 200 on it is yet? If so, can it be replaced?

[TmEE]

gimme a photo of that box

[CelticRedemption]

since someone else already took the liberty of posting it on the first page, I'll just steal his photo.

http://img168.imageshack.us/img168/3700/segacdfucked5ky8.jpg

the black box with "200" on it, I can't for the life of me read what else it says

[Baloo]

looks like "muRadar."

[CelticRedemption]

Aha, apparantly it's Murata... so it's a something 200 MuRata?

EDIT:

http://i119.photobucket.com/albums/o135/HemoPhagus/DSC01492.jpg

I took if off since it was shot anyways, it says 200 muRata, indeed, is this a transformer or something?

on the back, there's the C22 and C23... things... whatever they are, the C22 is completely blown up, nothing left of it, the C23 'seems' intact, but is probably also dead.

[Elliotw2]

muRata is a brand of electronics, they have a plant near where I live, most likely the 200 is either a rating, or a model number. Looks like a tiny transformer to me.

[TmEE]

It is an inductor, its used to filter out noise from the power fails. You an replace it with 2 wires and its very unlikely that it has fried/stopped working.

Edit: when I had my fuse bypassed and I accidently used wrong polarity power supply, I fried the green transistor in the top corner... I never replaced the transistor with another but a wire... only drawback is that when the AC brick is connected, the machine is powered.

[CelticRedemption]

and its very unlikely that it has fried/stopped working.


Do you mean it's unlikely it won't work if replaced by two wires, or that it's unlikely that this PART is fried? because i KNOW you're wrong about the second one. see that red coil part on the left? that part worked fine, giving power to part of my machine, that right coil? burned, blackened and molten....

But you say it's an inductor? What other stuff usually breaks when this thing fails? I know the fusible resistor was also broken, which I already replaced

[TmEE]

Unlikely the part is fried.... Did the darker side have any continuity ? if so, it would not be the troublemaker...

The green transistor in top left can be a troublemaker, without that working the machine will not power up...

[CelticRedemption]

Hmm... I took it to an electronics store, he said that the coils are probably not broken either, but on the bottom, there's these small parts labeled as C22 and C23 that connect the pins of those coils, and one of those quite literally blew up, and there's nothing left of it, that should be replaced i suppose.

That green part, how do i measure whether or not it works? mind you, i'm a total n00b =D


EDIT:

So.. I went back to the electronics store and took the PCB with me this time, they said that thing on the bottom isn't really needed, but they couldn't help me since the PCB was sorta damaged around one pin.

I took it home, decided to put that coil thing back in since they said it wasn't broken, cleaned out that burned pin, made sure it connected to the PCB using a somewhat more than usual generous amount of solder... Put the thing back together, and lo and behold, it turned on.
It goes to the play screen normally, reset opens the tray. But now it won't read discs.


I feel kinda defeated D:

[TmEE]

for discs, there's a great chance you will have to start replacing caps... MCD1s use bad caps that just dry or leak out and that will increse RF noise in the power rails which in turn interferes with CD reading...