REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart

[choijimmy]

As per service manual, its part of its initialization routine. Laser sees CD first but then doesnt see it anymore. timer runs out and ejects tray.

i

Cool.  Good to know this

[leonk]

there's a good flow diagram in service manual (full pdf on console5 wiki) that shows initialization logic. It's interesting that any failure resilts in "eject tray".

[Keith Courage]

original pic was down so here it is again.

[stt1]

Hi (my first forum post)!

Came to this forum for this thread... Saw a posted link elsewhere. I hope I'll have soon some new information to give (or at least give a fault descrption and confirm which of the previous hints worked in my case).

I'm not a newbie with electronics and have fixed some other equipment earlier. But now I'm with a pile of Laseractives I have been recapping slowly and trying to fix some issues. Got few hints already from this thread and will check out if any helps for problems I'm having. If not, I'll describe them better here that we can take a look together.

choijimmy: sent you PM, I need some parts as well.


What I can already confirm to other people: these things really need recapping nowadays. At least power supply needs to be redone, but whole machine recapping is recommended. I have now recapped five power supplies and found several caps already leaked in them. For testing purposes I also did measure one power supply caps, noted them to be good (except two small ones (changed them immediately) near fuses), but after some use the power supply gave up and when taking apart many caps in it had visible leak.

[stt1]

About opening the tray...

While searching information about problems (and how to fix them) with Laseractive I noted that few people have struggled with opening the disc tray when the system died. Couple of different solutions has been described, but none I found were the same I used already long time ago (and I believe many people knows this, but it's just not been written anywhere). There is simple and easy way to do this without risk breaking anything - assuming the tray system is not broken otherwise or stuck somehow (for example an item blocking the tray from moving).

1. Remove the power plug from wall socket
2. Open the Laseractive cover
3. Take a look under the tray from same side where the power supply is installed

Next to power supply towards to front panel you can see a motor attached under the tray. This motor is attached with a belt to a larger pulley (and when this belt is too loose, you'll have also problems with opening the tray and loading the disc while starting to play).

4. Turn that larger pulley with your finger

IMPORTANT: this same motor + pulley handles also rising the laser + spindle to upper position for playing the discs. Take a look to the laser and spindle while you turn the pulley, if they start to rise up, then you're turning in wrong direction.

In normal situations (tray system not stuck/broken) this pulley moves easily. It takes several turns that the tray opens, but this way you can open the tray still fast enough without worrying that the tray system gets broken while forcing it to open.

[stt1]

Some reporting:

It's really apparent by now that when the caps go bad, a lot of things may happen. The LA I'm working on didn't got a power surge (ie. did NOT die suddenly from over voltage, which could be really apparent in such large damages), it just gradually started having problems with disc (CD) playback -> in the end didn't play anymore disc whether CD or LD, just tried to do so...

Found out so far:

Several more or less leaked caps from various boards.

2.2k resistor in power supply transformed itself to something like 195K (causing the -5V line to be something else...)

Audio demodulator toasted (apparently due to -5V failure)

2x burned fuses on service board


What is remarkable is that none of the fuses in power supply went out. So, the supply kept feeding the system even while caps were leaking and voltage levels were incorrect.


After changing caps, 2.2K resistor and two fuses:

Laser led functionality looks correct (moves up/down again)

LD and CD are again detected correctly

Disc spins to apparently good speed (after parts change it didn't spin correctly before I made some tuning to potentiometer sitting on the laser led ribbon cable)


However, laserdisc playback seems to be not working yet. The Play-button led keeps flashing, not constantly lit as it should be in normal situation.


Now waiting for service remote, service LD and part shipment to get the audio chip etc.

[choijimmy]

Some reporting:

It's really apparent by now that when the caps go bad, a lot of things may happen. The LA I'm working on didn't got a power surge (ie. did NOT die suddenly from over voltage, which could be really apparent in such large damages), it just gradually started having problems with disc (CD) playback -> in the end didn't play anymore disc whether CD or LD, just tried to do so...

Found out so far:

Several more or less leaked caps from various boards.

2.2k resistor in power supply transformed itself to something like 195K (causing the -5V line to be something else...)

Audio demodulator toasted (apparently due to -5V failure)

2x burned fuses on service board


What is remarkable is that none of the fuses in power supply went out. So, the supply kept feeding the system even while caps were leaking and voltage levels were incorrect.


After changing caps, 2.2K resistor and two fuses:

Laser led functionality looks correct (moves up/down again)

LD and CD are again detected correctly

Disc spins to apparently good speed (after parts change it didn't spin correctly before I made some tuning to potentiometer sitting on the laser led ribbon cable)


However, laserdisc playback seems to be not working yet. The Play-button led keeps flashing, not constantly lit as it should be in normal situation.


Now waiting for service remote, service LD and part shipment to get the audio chip etc.

As per chat, try to turn the pot on the laser back and forward ( just make sure don't over 2PM position ) to see it helps.
Also, double check the service board, make sure No 3 legs transistors have bad/cold solder joint