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

[choijimmy]

unable to upload how main pcb look like due to  forum upload folder full ??

Basically, it is the pcb with a lot of pot which control the power/tune of the laser

[leonk]

sorry. No laserdisc and motor does spin freely.

Can you email me pics and I'll upload them? I'm leonki@gmail.com

I was originally thinking it has to be something in the PSU. 14/-14V go to main video board. There an op amp uses the 14V under directions from a processor to spin up and run the main motor. If 14/-14V is mission, I think most of the system will still work (as it mostly uses 5V)

I could be down the wrong path. But then again, solid state devices don't tend to fail from shipping. Loose parts makes more sense!!

[leonk]

OMG! I FIXED IT! BY MISTAKE I FIGURED OUT WHAT IT IS!!! THIS MIGHT EFFECT OTHERS AND HAS NOT BEEN DOCUMENTED BEFORE!!

Background:

On the body of the laser unit, between the laser lens and front of the system, is a copper tab sticking out.  Between that copper tab and towards the middle of the system is a thin copper wire.  On this thin copper wire is a small piece of square copper just hanging there.

Problem:

The laser moves all the way to the spindle, and detects it's a compact disc.  But that copper tab and square should go UNDER the hub of the CD spinner.  If they are bent a bit up, they hit the side/face of the hub.  This causes the entire laser lens to twist almost 30 degrees to the disc!  The laser no longer sees the surface of the disc, player thinks something is wrong, and ejects the disc.

Solution:

Very carefully, push down on the copper tab so it's more parallel/level.  The tab has to go UNDER the hub (black circle that spins the disc).  If it's kept flat, laser detects the disc and motor will start spinning the CD and all will be fine.

Solution 2:

Replace the entire laser assembly.

I wonder how many good lasers were thrown out because of this flaw!

[choijimmy]

Congrats.  Strange enough by shipping the whole laseracrive main unit will bend the little copper wire. 

I do see a lot of shipping broke the laser itself when just ship the laser assembly itself, once a while,  the copper wire is even broke and disconnected. 

In additional,  I am a bit surprised the tray will be ejected in this case,  I thought the laser will just sit back and keep the tray stay in the main unit.

[leonk]

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.

[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

[stt1]

Long time no message, but I have good news. I got the player working after all few weeks ago. No cold solder joints were found from service (or other) board. I was not able to get a good playback from the laser (picture was black and white + really distorded at the best) so I ended up taking laser from another good to know LA. After moving the laser from unit to another I carefully turned the pots to similar positions as in the donor LA. And voila, LA started playing all discs at once without problems. Also LD picture quality was instantly really nice.

Now I'm working on another unit (actually third...) and made some findings from the power supply. Here is the old list (by choijimmy) from previous posting:

R301 is 2.2k
R302 and R303 are both 220ohm
R304 in my board is a bridge, not resistor

The board I'm working on now has:

R301 = 2.2k
R302 = 2,7k - yes, red-violet-red (btw, this was broken 2,2k -> ~195k from the previous psu I was working on, and the broken resistor is still on my desk, it's red-red-red)
R303 = 220
R304 = 220

Is there a mistake in previous list? BTW, the markings in the PCB on solder side are a bit confusing, it's more clear from component side...

[choijimmy]

Long time no message, but I have good news. I got the player working after all few weeks ago. No cold solder joints were found from service (or other) board. I was not able to get a good playback from the laser (picture was black and white + really distorded at the best) so I ended up taking laser from another good to know LA. After moving the laser from unit to another I carefully turned the pots to similar positions as in the donor LA. And voila, LA started playing all discs at once without problems. Also LD picture quality was instantly really nice.

Now I'm working on another unit (actually third...) and made some findings from the power supply. Here is the old list (by choijimmy) from previous posting:

R301 is 2.2k
R302 and R303 are both 220ohm
R304 in my board is a bridge, not resistor

The board I'm working on now has:

R301 = 2.2k
R302 = 2,7k - yes, red-violet-red (btw, this was broken 2,2k -> ~195k from the previous psu I was working on, and the broken resistor is still on my desk, it's red-red-red)
R303 = 220
R304 = 220

Is there a mistake in previous list? BTW, the markings in the PCB on solder side are a bit confusing, it's more clear from component side...

What you mean previous list ? I am a bit confused the different between 1) old list ( by choijimmy )   2) previous list  3) the one you are working on.
Also, what is the issue for the one you are working on ?

[stt1]

What you mean previous list ? I am a bit confused the different between 1) old list ( by choijimmy )   2) previous list  3) the one you are working on.
Also, what is the issue for the one you are working on ?

Old list from previous posting = list of resistor values given on page 7 on this same thread
Previous list = I'm trying to point into that same old list

If you compare the listed resistor values you can see that there are some differencies. And it looks like also that R302 can be either 2,2k or 2,7k. Don't know yet why, maybe there was some production update.

I will try to have time for double checking the values from service manual next week.

No issue with the power supply I'm working on, it works fine and measured voltages are good. I just made some checking, noted those resistor values and replaced all caps on it.

[stt1]

Ok, service manual wasn't really helpful (at least my paper copy) in this aspect. It has the circuit board pictures and shows component locations etc., but there is no component value list, at least for caps or resistors...

So, I took a picture and added some ellipses on it. Please, see the attachment, this is what I'm trying to explain.

[choijimmy]

OK, service manual wasn't really helpful (at least my paper copy) in this aspect. It has the circuit board pictures and shows component locations etc., but there is no component value list, at least for caps or resistors...

So, I took a picture and added some ellipses on it. Please, see the attachment, this is what I'm trying to explain.

Oh, ic, you found my old post regarding the resistors values ( in page 7 )

yes, I confused the resistors position