Laseractive doesn't read Mega LD/CD

[deubeul]

Another Laseractive thread 

I received a junk laseractive last week. The tray opens (with a little help), but it would'nt read anything: any type of discs wasn't spinning.

I swapped the lens with another one (BlueBMW, if you read this, you can add the CLD-900 to the compatible units list) and now regular CDs and LDs play fine.

BUT Mega LDs and MegaCDs don't work. The discs spin, but don't launch. Cartridges work.

So I need help from the tech gurus to narrow down the source of the issue 

- If regular CDs and LDs play fine, should Mega CDs and Mega LDs also work, or could the lens be strong enough to read regulars discs but too weak to read games?

- Or could the Sega pac be faulty? I recapped it a while ago, so I quickly checked my old soldering job and it seems fine at first view, except 2 NP caps that don't look genuine  and that I'm sure weren't soldered by me.

- I read in some thread that it's possible to adjust the lens power, but I wasn't able to find info  in the service manual or in forums. Does anybody know wich pot(s) is concerned?

Thanks in advance  for your help 

[deubeul]

Sorry for the double post, but I was afraid my edit wouldn't be seen 


A "laseractive" search on the forum led me to the "REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart" .  How did I miss that 

Choijimmy provides some really usefull informations in that thread!

So I started by the laser lens pot: no luck.

To resume, so far:

- I have 2 working lens, one from a CLD-900 and one from another non working at all laseractive. Turning the pot didn't help with the two lenses. If I turn the pot clockwise too far (180° for a lens, 90° for the other one), discs wouldn't be recognized anymore.

- With their pot at its original spot the 2 lenses behave exactly the same.

- With or without the Sega PAC, Music CDs and Movie LDs play fine and launch really fast, even with a badly scratched LD.

- Without the PAC, it can read music tracks of a burned MegaCD disc.

- Without the PAC, my MegaLD disc is recognized: A message says that a Sega PAC is needed to read the disc.

- With the PAC, once a disc is inserted, the cursor moves on the screen's "play" button. I press the A button of the controller, the disc starts to spin, but nothing launch. The disc keeps spinning , I can move the cursor left to right, but the onscreen or physical eject buttons don't respond, the disc keeps on spinning with seeking noise from the lens every ~20 seconds.


All this makes me think that the problem does not come from the lenses, but from the PAC or from the INTF assy, but I'd like to hear opinions of members who have the knowledge and some experience on these units.

Any help would be greatly appreciated!

[schweaty]

I wonder if there might be a bios problem in the PAC.  I'm not real smart on the sega bios and how it works, so sorry if this isn't much help

[choijimmy]

I do see this problem before. 
- Once is solved by recap the INT assy and works for me.

- Once is due to one of the Big 3 legs transistor have cold/break solder join on the FTSB ASSY board ( the board with a lot of pots eg, focus gain, track gain,etc... )

- once is due to the faulty Sega pac which only work for cart but Not ld/cd even after recap.  I am Unable to fix this issue.

I would suggest to find any other confirmed good pac to test it out first.  The reason is take out those PCB boards from laseractive unit is pretty painful.

[deubeul]

Thanks for the reply schweaty, it could indeed be a bios issue, but I have no clue how to test it.
I tried to launch the laseractive with the bios removed, only a black screen shows, with no possibility to read any type of discs, even music ones.

Choijimmy, thanks to share your experience

I'll have a look at the transistors on the FSTB board, but I'll wait to have another Pac to test before touching the INTF board, this one is a real PITA to extract!

One more (dumb) question: The Pac can launch CD/LD games even without an ML2016/32 battery inside, right?

[choijimmy]

The Sega pac can work without saving battery

[deubeul]

Thanks,  I knew it was obvious, but i needed to be sure   

[choijimmy]

Update:
I am able to fix the Sega pac unable to read cd(keep spinning)by replacing the ic17 and ic 18, they are 64k ram for   
Cdrom decoder. (Mb8464)

[deubeul]

Thanks for the feedback, greetly appreciated!

[mario_pic]

Another Laseractive thread 

I received a junk laseractive last week. The tray opens (with a little help), but it would'nt read anything: any type of discs wasn't spinning.

I swapped the lens with another one (BlueBMW, if you read this, you can add the CLD-900 to the compatible units list) and now regular CDs and LDs play fine.

BUT Mega LDs and MegaCDs don't work. The discs spin, but don't launch. Cartridges work.

So I need help from the tech gurus to narrow down the source of the issue 

- If regular CDs and LDs play fine, should Mega CDs and Mega LDs also work, or could the lens be strong enough to read regulars discs but too weak to read games?

- Or could the Sega pac be faulty? I recapped it a while ago, so I quickly checked my old soldering job and it seems fine at first view, except 2 NP caps that don't look genuine  and that I'm sure weren't soldered by me.

- I read in some thread that it's possible to adjust the lens power, but I wasn't able to find info  in the service manual or in forums. Does anybody know wich pot(s) is concerned?

Thanks in advance  for your help 

track alignment may be messed also  iv repaired and restored a few  units so there not to hard to repair  also got a extra parts for the laser active   biggest problem with them  is if u leave a cd in them  and turn it off and move system or lift it up and put it on its side the cd falls off the cd tray and jams the  tray   most of the time people pry in it to open it and snap off pegs or push the  tray off of alignment pm me if ur intrested

[choijimmy]

Don't think it is due to track alignment.
If you read his original message carefully.

"now regular CDs and LDs play fine."

The player is OK to play music cd and movie ld.  Just mega cd and mega LD are Not good.

If track alignment for the LD player is bad,  I wonder how can it  play some type disc(movie LD /misic cd)  but unable to play game cd/ld.