pc-engine cdrom2 interface unit

[mrforever]

hello,
i've this unit buyed in good working condition and after 2 years i've opened it for play.
I mount all checked cables, attached pc engine white, put cd-rom game in cd-rom drive
when you boot up with a system card (I have a System Card 3.0) and press the run button, it just loads forever. The led on the right side of the CD unit says "PC", but the CD isn't spinning. It just hangs there indefinitely.

I opened up the CD unit for see the problem but i don't see nothing of strange or burned . Here is a picture:

i think that the fucked parts are one of fuse or spinning motor...because laser lens doesn't turn on with his red laser...
I hope that you can help me
thanks

[raisinland]

Sorry if this is obvious but take the CD off and see if the motor spins. On some consoles the spindle hub can get pushed down far enough that the cd contacts the surrounding plastic and won't spin.

[NFG]

PCE CD ROM drives use first-gen CD technology.  They're very flaky and prone to failure.  I've never managed to resurrect a dead PCE CD system.  

The IFU is also very often dead, so it might be that the CD ROM drive itself is fine, but the IFU is broken.

[l_oliveira]

There's a good chance you assembled the flat cables inverted.

The PCE CD-Rom drive is based on the old Sony Discman D-50 and D51 design. An Optical unit KSS-220 and the D-50 chassis plus NEC custom chipset for CD-ROM decoding.

It's a very resistant design and has awesome quality. But due to it's complexity I really advice people to not thinker with them. I own one of these myself and it has been serving me well since 1995. I bought it used and it had a weak laser. I replaced the optical pickup and adjusted with a O-Scope. It's been  running fine since then.

If you're able to find the D-50 or D51 service manual it will be incredibly helpful on fixing the unit.

as for the Laser (big flat cable) and coils (small flatcable) they can be easily inserted backwards and if they are, they will have electrical contact due to the connector design.

the coils flat cable should be placed with the ribbon facing the internals of the drive (going straight to the pickup, without flip)
as for the laser flat, the side with the solder point should face the outside of the drive
Pin 1 is the side with higher  bump:

  ||||||\
/||||S|||   (S is the anti static solder jumper)
||||||||||  (pin1)   

Match the Pin 1 on the ribbon and the pin1 painted on the board.

[Computolio]

    My TG-CD drive can read pressed CDs, but not burned CDs. Is there any way I can adjust the laser to fix this?

[l_oliveira]

You can raise the laser power a bit ...  but it will make the laser pickup die after a while.
Since it's really old technology it doesn't really "know" how to deal with CD-R.

I carefully tweaked my Rom-Rom drive (same kind as the one the original poster put a picture) with O-scope and frequency meter and it's
capable of reading CD-Rs. But even carefully adjusted it only read certain brands. I use TDK or Maxwell for it.

[Computolio]

    So would trying to get better burns be a more viable option? Does using older-style CDRs (with the blueish bottom coating) and burning them at 1X stand a chance of working?

[l_oliveira]

ya that comes without talking.
but considering the age of these systems pot tweaking might be needed.

I bought the ROM-ROM set long time ago (I think 1999) it had weak laser or the lens degraded. I exchanged the KSS-220A optical pickup and made normal CD adjusts like I would do to a early sony discman.

It read CD-Rs just fine, like would a old car cd player.

There might be a chance that the opto-mechanics on your drive are aging and it is making the problem appear on cdr discs

You could ask for a experienced technician to adjust your drive to see if it improves with cdrs.

[isodee]

Actually I got the same problem now.... My CD-ROM2 dosnt spin any cd or without cd..... should I mayby change the laser or can I fix it somehow?

[phreak97]

I realise this is an ancient topic, but I found today that a very common problem is one of the plastic gears. you'll see one of them is yellow.. for some reason that one only will turn to cheese after a while.
if the laser assembly doesnt hit the home switch it doesnt check for a cd so it doesnt spin the drive.

I didnt find a source for new gears but it's quite possible to convert it to a belt drive, which is what I'm looking into now.

[l_oliveira]

I realise this is an ancient topic, but I found today that a very common problem is one of the plastic gears. you'll see one of them is yellow.. for some reason that one only will turn to cheese after a while.
if the laser assembly doesnt hit the home switch it doesnt check for a cd so it doesnt spin the drive.

I didnt find a source for new gears but it's quite possible to convert it to a belt drive, which is what I'm looking into now.

I'll wait eagerly for your solution as mine did indeed turn into cream cheese. -_-;

[phreak97]

I managed to get it going temporarily by removing the ruined gear and the shaft it was located on (it unscrews, but not easily), then sliding the gear on the motor shaft a bit further to the end and using the ring off a water balloon as a belt.



then you need to adjust the tracking pot a couple of degrees at a time until loading times are at a minimum. I also adjusted the others but I dont know if I got much from it.

POT = Function, Test Point
VR101 = E/F balance, pin 13 of U101
VR102 = Focus Offset, pin 18 of U101
VR103 = Track Gain (Track error level), pin 45 of U102
VR104 = Focus Gain, pin 48 of U102
VR105 = VCO, pin 30 of U102

if you have a look in this thread there are three or four alternative fixes: http://www.pcenginefx.com/forums/index.php?topic=9383.45

one I found was to replace the motor gear with one big gear that skips the second gear and meshes with the third, then you swap the motor wires around to make it go in the right direction and it apparently gives much faster load times than standard due to being geared faster.

I think there are a couple of people in that thread who sell replacement gears too.

[l_oliveira]

The ring of the water baloon as a belt was a bright solution ! I'll try it myself.

[phreak97]

Haha, so long as you know it isn't permanent, balloons tend to degrade over time.

[ScoreAddict]

Sorry to unearth this old thread but I'm having issues with my CD-ROM2-unit!

So I've replaced the middle gear (which the seller had already removed) and now the laser doesn't read any discs.

then you need to adjust the tracking pot a couple of degrees at a time until loading times are at a minimum. I also adjusted the others but I dont know if I got much from it.

POT = Function, Test Point
VR101 = E/F balance, pin 13 of U101
VR102 = Focus Offset, pin 18 of U101
VR103 = Track Gain (Track error level), pin 45 of U102
VR104 = Focus Gain, pin 48 of U102
VR105 = VCO, pin 30 of U102

I'd say that my laser is pretty much bust, but I'd like to try the pots! Problem is, what are the standard values for VR101 to VR105?

When I measured the pots on my unit I got these numbers:

VR101 -> 6.76 kΩ
VR202 -> 8.69 kΩ
VR103 -> 14.50 kΩ
VR104 -> 16.23 kΩ
VR105 -> 385.5 Ω

Are these ok? I have no idea if the seller tempered with the pots before I got the CD-ROM2.

I'm going to buy a replacement laser (hard to get these days) and I want to make sure that the pots are set at correct values not to damage the pickup!

Any suggestions what to do?