Problem with my Sega CDX

Last edited by darkshadow1804; 06-18-2012 at 04:55 PM.

It have to be a laser problem . You have to replace it .

a laser problem? hmmm...but why can i play audio cds with the batteries?

Originally Posted by darkshadow1804

a laser problem? hmmm...but why can i play audio cds with the batteries?

Let say you have a ps3 right that play all ps1,ps2 ,and ps3 games. And it having problems playing ps1and ps2 games right but it can play ps3 games . see ps1 is formatted a cd-rom game right . Now for the ps2 games is formatted dvd right . If you have that problem it have to be the laser going out and needs to be replaced . Simple as that .

could be,
so that is the reason the sega cd mode just gives me a plain black screen, not the bios animation nor nothing else? D:

Originally Posted by darkshadow1804

could be,
so that is the reason the sega cd mode just gives me a plain black screen, not the bios animation nor nothing else? D:

That could be it . I mean usually a laser don't last long . lol . It would be the same for any game system that have a laser to me . Myself never had played a Sega CD or CDX system so I don't know much about it . I hope that I help you out some .

Last edited by Tokimemofan; 06-19-2012 at 04:15 AM.

Originally Posted by Tokimemofan

You are misunderstanding how these work, your PS3 example is misguided because a PS3 has 3 Laser Diodes either of which can die individually, a dead 780nm breaks cd-rom (Blue and Black discs CDs) 650nm breaks DVDs and 405nm breaks BluRay (and usually everything else as the ps3 starts it in 405nm mode to check for the presence of a disc) The Sega CDX only has 1 laser. A laser failure also couldn't cause the black screen problem. Check and make sure the bios is good and original, some people like to put a region free bios in these things, if such a mod is done wrong it would cause this as could a lifted pin on any of the surface mount IC chips. It is likely to be a hard to ID failure since there are not many simple problems that would still allow the Genesis and Walkman modes to run while disabling the bios completely. The symptoms are similar to a model 1 that had 4 lifted pins on one of the cpus. Get out a good magnifying glass and inspect every connection on both boards.
Edit: Another note, The BIOS will run without a laser assembly even being present, something I tested when part swapping to ID a broken part on one I had.

I just thought it might be a laser problem thank you for clearing it up .

Last edited by Tokimemofan; 06-19-2012 at 06:25 AM.

Originally Posted by Tokimemofan

Tomorrow I'll pop the lid on mine and see if I can find any leads.
Edit: just opened mine, you should get the BIOS background screen even when the CD daughterboard is missing, on the mother board look for IC numbers 1, 5,9, and 14, they should be in a square arrangement, the bios is IC11, check the area around all 5 of them for any damage. Also check the power supply daughter board, it is possible that one of the lines is damaged. Just a warning before you get out a screw driver, this is easily one of the hardest systems to open for a first timer since you will not be able to see everything you are doing.

Is there a way to fix the bios ??

I fix things. You name it, I'll work on it. Want something modded? Recapped?

Also marginally related here, the stock specs for the CDX are 9.5V and 1.5 Amp. You've got enough amperage in your new supply, but you're missing half a volt. This can be an issue with those systems, but the lack of BIOS screen indicates your problem is probably somewhere else.

I just wanted to let you know this since I've heard using an underpowered power supply can kill the laser in these systems.

Originally Posted by xelement5x

Also marginally related here, the stock specs for the CDX are 9.5V and 1.5 Amp. You've got enough amperage in your new supply, but you're missing half a volt. This can be an issue with those systems, but the lack of BIOS screen indicates your problem is probably somewhere else.

I just wanted to let you know this since I've heard using an underpowered power supply can kill the laser in these systems.

The lack of half a volt on the power supply shouldn't be an issue. Most consoles from that era run the input voltage through a regulator that drops the voltage to +5v. You can generally use anything between 9-12v but it still needs at least 1.5 amps.

I fix things. You name it, I'll work on it. Want something modded? Recapped?

A PlayStation 2 power supply works just fine, it is rated at 8.5v but the amperage is high enough (4x higher than required) to voltage drop to the proper range.

Originally Posted by Tokimemofan

A PlayStation 2 power supply works just fine, it is rated at 8.5v but the amperage is high enough (4x higher than required) to voltage drop to the proper range.

yup, i used a playstation 2 power supply cuz i heard it works great on the CDX (with its 4 amps), but the results are the same...
and i discovered something, when it gives me the black screen, if i press the reset button repeatedly, often gives me annoying buzzing sounds with a red, light blue, white, green or B/W vertical bars across the screen!!! WHAT THE...!!!

i think i'll have to re-open it again, and yeah, i know it's a bit difficult to disassemble and taking everything apart, but i've done it like...5 times? so it wouldn't be a problem, i'll check the pins of components around the bios one

so right once i had this fault it was a bad pad on the bios had rust on it.

Originally Posted by APE992

Assuming the CDX has a 7805 voltage regulator inside it wouldn't matter too much. I'd still be concerned about the current due to the fact that those numbers are probably burst and not a sustained output.

I do not see a 7805, just 2x B1267 transistors and 2x unknown component s30-03. I think the voltage regulator may be made from discrete components, the power socket is on a small daughter-board that seems far over-engineered for it's purpose, there are 4x 470�f capacitors that seem to be for ripple filtering (something that is already done in the MK-4122) and 2 large inductors, it just seems to be doing way too much with too many individual parts. There is also the complete lack of a heatsink that the 7805s are normally bolted to, not that those would actually fit in the case. That may also explain the prevalence of the F1 problem.

well, the small power supply board seems to be fine and no track is broken or damaged whatsoever
i found a bad capacitor in the CPU board so i replaced it, and cold solder joints on the VPUs (IC9 and IC14), so i decided to re solder very carefully, after a few tries the cold solder turned shiny, but now the genesis part shows a jumping image with a lot of rainbow banding and a lot of hissing noise in the AV OUT (but in the headphone and line out jack sounds perfect)
maybe i'm screwing it up more than fixing it...i'm about to giving up and get it back to the guy...cuz he sold it to me in about $150 (U.S Dollars) saying that works nice, so, i'd get my money back =)

Pinballing since 1977, video gaming since 1978, console gaming since 1979, computer gaming since 1981. Growing old? Never!