Problem with my Sega CDX

[shadowkn55]

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.

[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.

[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.

[darkshadow1804]

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

[raylydiard]

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

[Tokimemofan]

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 470µf 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.

[darkshadow1804]

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 =)

[ScoreAddict]

Hi!

I have a very similar problem with my CDx!

Description over here:

http://www.theisozone.com/forum/view...p?f=65&t=46155

Maybe some of you can help me?

All the Capacitators have been replaced and the battery is charged at 2.57V (maybe too low?). Power supply is original (Multi Mega or PS2) so it's not that issue.

I'm wondering if the RAM or BIOS could be the issue. Is there any way to enter the BIOS or do a "factory reset" on the console?

[ScoreAddict]

Addendum:

A cheap replacement for the ML-2016 (3V, 25mAh) rechargable battery in this console is the VL- or ML-2020. It is used in the remote control for some BMW-cars - price at about $7-$8 (5 Euro). Should also work for the Sega- and Mega-CDs expansions.

Everyone else on holiday?

[ScoreAddict]

Addendum:

Old ML-2016 rechargable battery replaced with a brand new VL-2020. Issues remain.

So it's not the voltage of the battery.