Sega CDX problems

System does not boot cartridges and shows black screen when one is in.
CD bios loads silent with no animation but with picture lcd orange but blank.

 

Was the system working before? Has it been recapped?

 

Bought it broken. Has not been recapped but I did check a few with my capacitance meter they seem fine. Someone worked on it before. The prior work was done properly by the looks of it but probably didn’t fix it, I have no knowledge of why it was worked on but most likely the same reason I am working on it.

 

Thats the problem with 'bought as faulty' retro hardware, there could be any issue made even worse by a previous owner.

There seems to be solder iron damage to the VDP (315-5660) and possible bridging near the cart slot. Not sure why the previous owner was trying to solder there. If the VDP is dead, spares can be harvested from Model 2 Genesis if you are feeling brave.

It might also be worth looking at replacing the caps anyway. This thread might give some ideas, though that CDX is far worse then yours. https://assemblergames.com/threads/sega-cdx-issue-need-advice-or-parts.56914/page-2

 

Near C46, that looks like a water damaged area. Are there traces on the underside eaten away?
On the 5660, pins 157/156 are bridged, as well as pins 152/151 (check with multimeter and verify the 5660 pinout).

The empty pads on the PCB edge near IC8 / C27 also look suspicious. Are they supposed to be empty?

 

The pads near ic 8 look fine but I’ll compare to another unit tomorrow
The 5660 pins are fine, that’s just flux. There is water damage near the cartridge slot as well that’s why I was soldering the pins on the 5660. I think the prior owner tried to fix the no cart boot and the no cd access as 2 separate faults.

This is sooo stupid. Turns out that the sonic cart I was using was bad. Genesis slot is fine Sega cd bios still hangs. Probably dealing with a communication issue on the cd drive. Wasted half a day on a wild goose chase and still no working cdx. Btw the cd drive is dead in Walkman mode too

Success! The water damage was the cause but not on the main board. The vias under the lc66306a were corroded away. Had to remove the chip and run patch wires through them. Still not working fully, but I can get a few seconds of an audio cd to play and the basic functions work.

 

Good luck with the rest, you'll succeed!

 

Nice work. Good luck with the rest of the repairs.

 

Finally finished, the laser tracking motor was cause of the remaining problems. Opened the motor and cleaned the brushes now works great

 

Did you manage to fix this one ?

 

Did you read the thread? The answer is within

 

Great job! Wow sounds like an epic repair.

did you take pics of this? it would be great for documenting repairs. I try to take pictures of my repairs these days, since you never know what could help someone else down the road...

Funny side note- today I pulled VRAM from that rusted CDX in the mentioned thread. It totally saved a Genny 2

Note, not all Gen 2s have CDX guts. In fact, it can be a real pain sourcing a 315-5660 model.

 

No I didn’t, it is a pain to do though. I might write up a tips and tricks guide for that sort of stuff at some point, so many parts are unobtainable or unidentifiable even if generic it would be a great idea to piece together a list of those. This isn’t even the first time I have had to open a motor to fix a CDX. I don’t expect it to be the last either.

 

Picked up one of these cheap that was "broken", played with the laser potentiometer for a few seconds and it's working, but I have a new laser and a capacitor kit coming while it's disassembled. Super cool system, but a pain to disassemble for sure.

Anything else that should be done to it while its open, not too familiar with this console. Sorry to thread hijack

 

Test it with a game that tends to have audio problems like Sonic CD, Lunar or Vay

 

Sonic CD played fine with the lid switch taped down and Sewer Shark FMVs without lagging. The new laser was only $11 so may as well swap it in. Thanks for the tip.

 

Sonic cd and lunar often have problems restarting a track. Vay often has lagging audio, never tried sewer shark though, can’t judge. I suspect a lot of people are replacing lasers unnecessarily. I never would have suspected a problem with the tracking motor because the laser was moving smoothly but swapping that fixed it. After opening it I found minor oxidation on the contacts and cleaned with a pencil eraser.

 

Well mainly it was that at $11, I'll likely never have to replace it again and then the capacitor kit I've heard these are terrible for that issue so I picked it up as well. I don't like those pins connecting the two boards as I can see accidentally bending/breaking one during later disassembly. I should have made a pictorial during it, but had no idea what I was doing either and just winged it, had to google about those pins once I saw them though.

I see what you're saying now about the lasers, it's just better to prepare in advance when buying dead consoles to just buy a new laser from China instead of being scalped 2-3x the price by a local distributor once you come to that conclusion after trying what you and I did I (process of elimination) suppose.

 

Wanted to give an update the new Chinese laser is actually worse than the 20 year old or so one that was installed. I cannot get the audio to play on Sonic CD and other games are stuttering like Prize Fighter while fighting. I tried to 'tweak' the laser potentiometer but it only gets worse from the default. Not sure if I can say I recommend them, maybe if yours was totally dead.. One other thing is if you are swapping in a new laser, be absolutely sure you find and put the very tiny spring that pushes the plastic gear arm into the assembly gear safe otherwise it's not going to work. I didn't even notice until I saw a spring on my desk after reinstallation and it wouldn't move down the track. Very pain in the ass of a system, not surprised with it being from Sega. Also mine had mod work from the factory I didn't see in other pictures of the boards so be careful with random wires and where they go. I don't recommend even opening one of these if you aren't well versed in console repairs.

Also the ribbon cable from the CD board that goes into the laser is extremely fragile, push the laser unit gently all the way to the back of the track before even trying to turn it over or you are going to tear it in half.

 

I wonder if anyone ever had any success with these cheap chinese lasers in any of their consoles?

I only have experience with lasers for the Dreamcast, and they are pure crap. I once managed to get an audio cd playing, but never any games.

Is it even possible to source replacement lasers for old systems anymore?