Sega CD2 not reading 100% part 2

[omp]

Hello all

I decided I would update this here as it makes more sense.

Following from my original post http://www.assemblergames.com/forums...ding-100-issue there has been a minor update/sidestep.

I was lucky enough to get my hands on another "faulty" Sega CD2 model 4102A that has a JVC optima 6 laser fiitted. This unit I will call unit 2. Unit 2 was absolutely filthy and after a minor clean up and new laser worked flawlessly.

Unit 1 is the original "faulty" Sega CD2 that I had and worked strangely. If I played a game the music would lag, I used Sonic CD as an example and here is what I got
-No intro music
-when starting game music wouldn't start until 4 secs (off timer) into game

Unit 2 works ok.

Ok both unit 1 and 2 have NEW lasers fitted.

I took the laser sled from unit 1 and put into unit 2 and had the same lagging problems. I put the unit 2 sled into unit 1 and it worked flawlessly leading me to come to the conclusion the sled is the issue.

From my original post I believed that the previous owner of unit 1 had fiddled with the pots (on the sled board not the laser) and since there are 4 it would be a bitch to wing it to get back into it's original position. I eye-balled the position of sled 2 and tried to reflect on unit 1 sled, that didn't work as I suspected (having set-up circuit boards for battery chargers for when I was working as an electrical fitter).

Is it of the opinion that I could take it to an appliance repairer and give them both units so they could use their osciliscope equipment and take readings from unit 2's sled and try and match them onto unit 1's sled? I don't have an oscilliscope and wouldn't now what I am looking for in a "cd player" setting.

It would be a shame if I binned unit 1 as it seems so close to working properly. I could of course sell it as a faulty unit.....

Unfortunately I am having less and less time to spend on console repairs these days after having our first child.

Any help appreciated.

Cheers Pete

[retro]

Without a service manual, it is unlikely that a television repair shop would want to touch it. Generally speaking, you need a special CD to adjust a pickup. I doubt that such a repair shop would have one for a Mega CD, although it's possible they could get somewhere with an audio test CD.

The main use for the service manual is locating the correct test points, specifications and procedures. Without these, it is somewhat difficult to reliably adjust, but I guess you could get somewhere with the general specification of the laser diode.

[omp]

Thank you for your reply

Ah that's a shame, it's probably not worth the expense or the trouble. At least I can make 1 nice unit from the 2 and someone may need a motherboard to suit a JVC laser (as there is nothing wrong with that). I do have a Sega Saturn here that needs a new laser, so I can use the spare laser in it.

Thanks again Pete

[retro]

Yes, there's also the cost that such a repairman would charge. It's probably more worthwhile keeping it as a spare. Maybe try to replace the CD drive with a flash card system, if you're so inclined? ;)

Yes, you could use the Optima in a Saturn, depending on what model it is.

If anyone does happen to have a copy of the Mega CD service manual, I'd be interested to see it! I have a copy of the Pioneer LaserActive one somewhere... not sure I have the add-on, though!