Sega CDx=strange issues, tech tips?

[ifkz]

I bought this expensive system as a broken project a decade ago and I made it better but it is not 100%. Currently I use it for ToeJam and Earl 1&2 and the odd game of Silpheed or Final Fight CD (when they want to run). Here is a rundown:

*It only detects the first player port. With or without a controller, player 2 is not seen. Both player ports had their solder reflowed.
*Only cartridge games that work are 4mb, 8mb, and (I assume 16mb). I have re-flowed the cart pins.
*The laser could stand to be replaced, but that would not fix the underlying issues. Lunar 1 works, Road Rash CD does not. Shining Force CD does not. These are original games, not burned discs.
*I reflowed the video pin connector while I was inside. It helped clear up most of the interference, sort of like RF interference.

There are no graphics glitches and there is full sound.

It is on my desk otherwise and audio CDs play with a skip here or there.

Any thoughts?

[Olivar]

I ran into something similar with a MegaDrive once, for the port it was a broken connector on the actual socket that caused the problem for me.
So double check the soldering on the mainboard of the Genesis/MegaDrive and check that each pin is properly connected and has no broken solder joints.

I have no clue about the cartridge issue, this sounds really odd. If the size of the memory really matters, then for me it feels there's something odd when the CPU tries to address the larger address area.
Could be a bad trace, or a broken pin in the address banks of the CPU??

[ifkz]

Checking the pins on the control port was a good idea and they are all there; no corrosion either. I beep tested the solder joints, also.

Yep, odd problems and I found out today that Phantasy Star II and Starflight also don't work and those are smaller "Mega" games. In the unit, I saw some corrosion inside on the cartridge board on one of the large square Sega marked chips right near the cartridge connector. If I have to guess, that's my problem; probably at one point had someone use it as a CD player, the batteries leaked, and now it has these odd issues. I cleaned up the small spot with vinegar, 90% rubbing alcohol, but no change. The legs still look intact on the pads. It is such a fine pitch that I dare not do anything else.

One other odd point, it only has sound on the left channel in game using cartridges. I don't know if this is new or I only just noticed it with my Outrun cartridge. Testing it with an audio CD by pushing play gives me both channels (system not powered by activating power button). Testing an audio CD in the Sega CD bios CD player also gives me both channels. [EDIT: Weird!!]. Tested audio CD was YES Highlights-The Very Best of Yes- recommended!

On the bright side: this has been my on my desk during work from home and it has been nice to have it run demos of Vectorman, Sonic 2, and it's always ready for a 1 player game of Toejam and Earl. Having played a full game of Silpheed on it the night before, I can say that the photon torpedo is the weapon of choice for the last boss. Don't pick the graviton bomb, it does not work! It's my good buddy for my workday. Some happy gaming on it is still left.