Extensive DC Reconstruction

Just to confirm, I did this with a laser from a Samsung CD-Master 40E Model SC-140, worked straight away, no adjustment needed. Suddenly that box of old CD-drives I bought a few years ago doesn't seem like such a waste of space, even if only one of them turned out to be any good haha.

 

thanx! good to know, i've tried several samsungs and all were too far form the disc making it useless, none of the ones i've tried were from a 40x cd drive, all were from 48 a 52x

 

replacing with a CD drive lens would still be able to read GD discs?

 

Yes it does, though I think the laser I put in might also be dying, it reads some GD-roms, all CD-rs and the like but some GD-roms it just doesnt even know are there.

pc_91, what happens if the distance from the disc is wrong, does it just not read anything?

 

Padoca85, yes it would, actually the lens is only a laser diode, a photodiode and a couple of mirrors, as the wavelenght of the gdrom is the same on the cd, only changes the amount of data on phisical size it works like an an original drive.

Hedgeyourbets, if it's too far is going to read bad or even not read, the top lens is moveable to make focus on the disc, if is too far on some parts of the disc that has deformation is gonna have a hard time reading, in my DC that had a dead spindle motor after replacing everyting it wouldn't read because of this, i've had to lower de spindle dish (that thing where the disc clicks on the motor) and now reads flawlesly, note that i've had to remove the top plastic of the drive if not the disc would touch it and read bad

 

GD-ROMs and CD-ROMs are basically the same technology with some slight differences rendering them incompatible...superficially. As demonstrated the real challenge would seem to be finding parts that are physically compatible and use similar enough communication to fully function.

I suspect I might just be nuts but it does seem like different GD-ROMs have different levels of playability across Dreamcasts even when factoring in the two different manufacturers of GD-ROMs for the system. Suppose it could simply be that one GD-ROM is scuffed/scratched a bit more than another or perhaps just in the right place.

While I prefer a scientific/objective approach in such matters it almost seems like voodoo.

 

I know exactly what you mean, I have four dreamcasts, no two GD-rom drives seem to read all discs in quite the same way, often if I have a game which doesn't work, I just pull another dreamcast out of my cupboard and away it goes. Interestingly, the best GD-rom drive I have came out of a very heavily used launch dreamcast. I'm vaguely considering doing some sort of primitive laser dance every time I insert a disc from now on, pray to GD-God or something.

 

if it was a lauch DC i probably have an yamaha drive, yamaha is know for making stuff more heavy duty than samsung does, i wouldn't be surprised if the yamaha drive lives 3 times than the samsung, is just better, not just the lens, one critical point of a CD/GD drive is the spindle motor, in case of cd is absolutely necesary to spin at correct speed to achieve CLV, i guess GD is CAV which is not as hard as CLV but pretty hard for a simple dc motor, as electronic repairman and audio hobbyst i know than most failures on cd players rely on bad spindle motors, the lack of a good bearing is critical on this.

 

What drive speeds should we look for to exchange the laser?

 

almost every lens i put in worked, except for the focus problem height, i ended up using the lens from a 32x aopen drive which the focus lens was clearly upper than on every other lens, actually the lens from the original dc and from a samsung cd master 52 or cd master 48 were exactly the same except for the focussing lens which on the original dc lens was a little more up

 

I just emailed nec uk and i am going to try and see if i can get official replacement's.

 

Could aleatory reading of dreamshell sd adapter ,be related to bad gdrom lenses?
Because one of my dc i calibrated the lenses and seems to some times read the sd card,others tells that didn´t found the sd card :/
Does anyone experienced this issues?

Regards

JOSÉ

 

Well I tried the only 3 CDROM drives that I have and they don't work 1 had more than 17 pins and the other 2 have completely difrent assembly.