SegaCD No Worky

[Jedi Master Thrash]

I found a Sega lot at the thrift store for 15$ last friday, including:

Original genesis 1 (the one that has the extra controller port on the back)

SegaCD 1

Two original sega-brand 3-button controllers.

1 sega RF unit

1 sega genesis power adapter

I thought that was a great deal. I know the model-1 CDs are sought after. Unfortunately the CD doesn't work... Everything else works so I'm hoping I at least came out on par. A working genesis power adapter alone is wort at least 5$.

The segaCD never turns on (I have a working genesis/CD1 already setup at home, I just moved all the connections over to ensure that none of the cabling was a problem. So yes, I do know that the CD requies its own power).

I read through the past threads. I tried shuffling the genesis-CD connection, but that didn't do anything. The next thing I'll try tonight is seeing if the fuse is out. However, I'm worried about that. I've never had much luck with fuses. In my experience, a blown fuse usually means blown-out power logic. I've had both a VCR and a receiver blow fuses, and when I replaced the fuse, immediately upon re-applying power (turning it on), the fuse blew out again, usually accompanied by a ball of lightning and the smell of spent magic. Yes, I matched the volts and amps on the fuse right.

So, just incase the fuse thing isn't it, or doesn't work, can you recommend anything else?

If not, maybe I can sell it to somebody cheap. It might be worth something to someone for the laser lens or CD tray or something.

BTW, does anyone know of a good place to buy fuses? The last time I tried to find a fuse (for a Sony receiver that was less than 5 years old), I couldn't find the correct sized fuse anywhere. Radio shack had nothing rated for enough amps. Best Buy and other related stores had nothing. I tried a bunch of auto-part stores that sell lots of car-audio stuff, and finally found a fuse with the right ratings, but it was about 25% bigger diameter. It barely fit into the metal holder. My wife had the same problem when she tried to replace a fuse in her car amp. Checked every store there was and couldn't find a fuse that was the right shape and was rated for enough amps. What's the deal here? Why should it be so hard to find fuses for common household electronics? Especially when they have such a large selection of just not the right fuses?

Thanks,

JMT.

 

[gameboy900]

For the SCD you just need ANY 1 amp fuse. The size doesn't really matter as long as you can attach it to the contacts somehow. I know in the SCD2 the fuse is shaped like a diode which is nearly impossible to find. But like I said you can just get a 1 amp fuse and a fuse holder for it from radio shack. Then just solder the fuse holder leads to the locations of where the old fuse was attached.

 

[Berty]

if you dont want to replace the scd fuse then i will gladly buy it from you as i have been looking for one now for a while and i am willing to try my luck!

 

[Jedi Master Thrash]

Ok, this is slightly more difficult than it should be... I can't find the fuse!

Here's a picture I took of the inside of my SegaCD. It's about 800k. Point out where the fuse is to me.

http://wisegirl.dyndns.org/sega/segacd.jpg

I ripped the whole thing apart and checked the underside of the boards as well. Nothing that looks like any fuse I've seen. That little box directly above the power input contans a red and blue coil side by side. It doesn't look like any fuse I know of, looks more like a selonoid.

On an amusing note, there was a game in the unit. Joe Montana's NFL football. Probably worth 25c or less.

On an unamusing note, I tried looking under the "battery" cell in the top left (the circle outlined in blue). I was dubious that there was actually a battery there, because that thing is incredibly thin, and there's a gap inbetween it and the board. In the process of lifting up the disk to look under it, I broke the spot welds that were holding the bottom connector onto it. Apparently that is the battery, just a really really thin one. But the battery connectors don't have any memory, so I can't make them press against the battery on their own. Anyone know how to repair it? I'd think that if anyone needed to replace the battery, they'd have to deal with this. In the interim, I placed some foam underneath the bottom one to push it upwards, and then I'll put a twisty tie around it to push them all together. If the battery was dead, would that prevent it from turning on? Or does that only affect the saved data?

Thanks,

JMT.

 

[fonzievoltonov]

I have a segacd2 but i think its this one (in orange).

can anybody confirm?

For the Battery, this will disable saves.

You need to solder it if you can (fast solder to don't damage the batt).

 

[Jedi Master Thrash]

That thing you pointed to looks like a resistor, except that it's green, and instead of the ohm color bars, it has the words: LF 2 1/2 A (where the F is inside of the L shape). Would this be a 2.5A fuse then? I've never seen fuses that look like resistors before. As gameboy suggested, I could replace it with a regular-looking fuse and it should all be the same?

Thanks,

JMT.

 

[fonzievoltonov]

Lots of fuse looks like resistors ^^ .

Youre maybe thinking about Electrical fuses with a little glass protection and 2 metalic borders but in Electronic the fuse are commonely like that.

You should look if the connection is cut (broke) between the 2 sides of the fuse (with a continuity tester).

Is it possible to have a confirmation from a segacd1 user?

 

[Jedi Master Thrash]

I don't have an actual continuity tester, but i just took a battery and used my voltmeter. There appears to be no continuity, it reads 0 volts across it (1.3v directly on the battery).

It's amazing that I could get a masters in electrical engineering and not have seen one of those fuses before... I think the college cirriculums need a few more practical courses. We never even had to solder in school. I just did that in the ACM SigArch lab (and that was for modding my genesii).

Thanks,

JMT.

 

[Jedi Master Thrash]

On second thought, maybe that's not it. When I turn the battery around, now I can read voltage through the supposed fuse. It appears to be functioning like a diode, it only works with the negative terminal of the battery touching the top.

Thanks,

JMT.

 

[Jedi Master Thrash]

So, even if I can get (one-way) continuity across the fuse, do you think it still might be the fuse that's the problem, and it might work if I replace it? Or should I be looking somewhere else?

Thanks,

JMT.

 

[lordofduct]

Ok, ummm, i havent looked inside of one in a long time... but, isnt that ribbon cable coming out from under the cd tray supposed to be plugged into that board on the top there....

i mean i hope its not something that simple, but i dont know, just looks weird in that pic to me...

 

[Jedi Master Thrash]

I had to unplug that cable on purpose in order to remove the CD unit while I was checking it out. It was plugged in originally when it wasn't working. I still haven't put the thing back together yet since I'm waiting to see what I can do to fix it.

JMT.

 

[gameboy900]

Best bet is to try tracing the connection on the board from the power connector and see what the first component it hits is.

 

[Jedi Master Thrash]

Is it safe to probe the unit while the power is plugged in? I figure it might be easier to see where the problem is that way. I just don't want to fry msyelf, my multimiter, or the segacd anymore than it already is. It's only 10v and 1a, it shouldn't be too bad.

Thanks,

JMT.

 

[Jedi Master Thrash]

I'm sure noone's still following my soap opera, but my latest update. I probed around, and I've got 13.4 v coming out of the power adapter (funny since it's only a 9v adapter...), and I can read it on one end of the supposed fuse, but I can't read it on the other end. So I assume the fuse is hosed then?

JMT.

 

[mal]

It certainly sounds like it.

 

[Jedi Master Thrash]

SegaCD Yes Worky!

But not without a long, tense, painstaking battle.

Most of the problems caused by my apparent inability to solder. Solder will simply *not* melt on either the tip of the iron or on the wire the iron is touching when the iron is touching the wire. (referred to as problem A).

When the iron is not touching anything, I can melt solder by touching it to the iron (30w). When the iron is touching metal wire or connection point, I can still melt solder farther up the shaft of the iron, but i can no longer melt solder within 1cm of the tip of the iron, and solder will not melt on the wire or connection itself. I bought the .032 60/40 Rosin core solder that was recommended I have 22gauge wire (it was the thinnest stuff they had at radio shack, would have preferred 24).

Since a proper solder joint requires the solder to melt on the wire/connectin itself (they have to be hot enough so the solder flows instead of balls), obviously I had serious troubles.

I also was tinning the iron before every attempt (thousands of attempts) by melting solder on the top and rubbing the sponge.

So basically, here's how my half a day went:

First, I opened up my old receiver (which my wife destroyed by plugging it directly into a wall outlet without a surge protector), and de-soldred the fuse-clips from it.

Then, i de-soldered the fuse itself on the segaCD. This wasn't an easy task since the solder wouldn't melt if I touched the iron to the fuse leads, I had to touch the solder itself. This leads to problem A.

Problem B: the solder remained inside the hole. The tip of the iron wasn't long and pointy enough to reach all the way inside the PCB wire hole, and the solder won't melt just by contacting the the iron with the connector, or a wire touching the solder. And the de-solder vacuum didn't such all the solder up when I was removing the fuse. So there was a thin by strong barrier of solder in the PCB hole, preventing me from sticking my wires in. After an hour of trying to get rid of the solder using the iron, wires, and de-solder vacuum, I eventually just pounded the sharp tip of a nail into the hole with a hammer. It worked, and I managed to not damage the rest of the board. I wore-off some of the sides of the hole connection, but enough was left for it to still work, and I could not fit a wire through the hole.

Next, I soldered wire to the two ends of the fuse-clips. The clips had a short stub that I could use to fold over the wire, and I also folded the wire itself, so as to create physical strength at the joint. Most of the hundreds of attempts at getting solder to melt at this joint were unsuccessful. Somehow I just think the wire and the fuse clip just sucked heat off the tip too fast. Most of the tip the solder would just bead into a ball, if I could actually get it to melt near the tip, and not stick at all. Eventually I got 2 good solder joints, and a couple of embarassingly ugly but sturdy-enough joints, such that the fuse clips are now rasonably firmly attached to the wire.

I believe at this point, I had burnt a 1/4in welt into the side of my left ring finger, and singed most of the hair from my right pinky. Holding the soldering iron "like a pencil" has the ill effect of me mindlessly grabbing too far up the shaft with my fingers, among other mindless acts.

The last part was the solder the wires into the holes on the PCB. I bent the wires at the bottom after inserting to add physical strength. Then tried soldering. I needed solder to melt down the wire to fill in the hole, to make sure the wire would connect to the leads in there (since I'd damanaged the contact points with the nail). Unfortunately, due to problem A, solder won't melt on contact with the wire. I even try getting the melt started by touching higher up the iron shaft, where it does melt, and then dragging the molten ball down the shaft towards the joint, and the ball actually freezes solid by the time it reaches the tip, since the tip isn't hot enough to melt the solder.

By sheer miracle, for one breif moment, solder magically started flowing down the wire, and formed a beatiful joint as it came out the bottom (actually the top of the PCB). I tried again and again to get more solder so I could also have a good connectio non the top as well as the bottom, but no luck.

I even tried my variable-watt iron, which can dial from 10 to 100w. Believe it or not, even at 60w, it seems to have a harder time melting solder on the tip than my 30w. And I couldn't get it melt anything at all when touching the wire. It just plain doesn't make sense. The god of solder must spite me. I didn't want to try higher than 60w while in contact with the PCB.

For the second wire connection on the PCB, I managed to get a "good-enough" but awful ugly solder connection.

I also managed to give myself a third degree burn on my right index finger. It turned that crusty yello look that hot-dogs get when you cook them over the first right before they get burnt. I also almost melted through the cord on the soldering iron. Man that cord just won't get in the way.

I decided not to solder the batter back on. I just stuck with my original trick. I put some styrofoam underneath to prop the bottom-contact up, and twisty-tied the batter so it presses down against the contact.

Using the fuse-clips is nice. Now i can just pop-in and out fuses without having to resolder anything. I popped in the 2.5A fuses I got at radio shack, and it blew out the moment I plugged it in... I was gonna scream. But there was no smoke or blue lightning, so I hoped the unit was still OK, and it was the power outlet or something.

Luckily I had some 8A fuses around from when I'd tried to repair my receiver. I plugged in an 8A fuse, and walla, it works! For the record, the 2.5A fuses where 250V fast-acting fuses from radio shack. Is there anything about that particular type that would cause it to not work? (they didn't have 120V, does that make a difference?).

So in the end, I'm rewarded with a working SegaCD Model 1. Whoever buys it from me may wish to re-solder where the wires connect to the PCB...

So, I'm left worried. My next endeavor was to finally put my multibios on my old segaCd model 1. Clearly, if I can't even melt solder on a joint, I'm screwed. I need any help you can give me!

When I was modding my genesii in the electronics lab at school, I never had this kind of trouble! They had a temperature controlled soldering station. I'd just crank up the temperature, and solder would melt easy and create perfect joints. I'm thinking I should pick up the 60$ digital temperature controlled soldering station I saw at radio shack. Of course that's a lot of money to spend just to play ranma 1/2 on the segaCd. I could just buy a darned japanese megaCD on e-bay for the money I've invested into my home electronics lab!

Obviously every other person in the known world had no troubles soldering electronics with their 30w (or even 15w) soldering irons. What in the world am I doing wrong?

Thanks!

JMT.