Author Topic: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide  (Read 30589 times)

blueraven

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Hello Everyone,

I will have the differences between the PCE/Turbo/Duo-R listed in the next few weeks; one of each is in for repair right now. If people would like to chime in with tips, corrections, or additions, please do so and I will update the guide. A section on adjusting the posts will be towards the end as soon as I have gathered all the information.  For each successful repair you will need:

1 HOP-M3 Laser
1 Duo (Turbo Duo, PCE Duo, Duo-R, Duo-RX)
1 Torx T-10 bit/screwdriver with a security center (Japanese Systems)
  OR
1 5/16" Gamebit (USA Turbo Duo)
1 Small bottle of White Lithium or Clear Silicone Grease
5 #40 x 1/2" Phillips head pan screws to replace the T-10's (optional)

PC Engine Duo (Black):



There are two generations of the PCE Duo, this being the first gen with the "Large Capacitor" as chop5 has pointed out.  First, flip the duo over and pull out each of the five Torx T-10 screws. A T-10 with a recessed center point can be purchased at Sears or a Hardware store. A regular flat t-10 can be used but it's harder to navigate around the center security bit and you risk rounding out the screw.

http://www.sears.com/shc/s/p_10153_12605_SPM518398701P?prdNo=14&blockNo=14&blockType=G14



Once you remove them, put them in a small cup or shot-glass to make sure you have easy access to them I reccommend replacing them with a comparable phillips head (take one of the screws to your local Ace or True Value Hardware Store and get five #40 x 1/2" pan screws) so you don't have to deal with the headache again.

Now that the system is open, carefully lift the cover directly off of the board and bottom casing. Take your time so you don't harm any of the internals.



NOTE: The unit pictured has had a complete cap replacement with green hi-temp NTK capacitors, so if yours are small and silver, don't panic, this is the normal OEM setup. Now, Zooming In on the Laser area...

The motor for the laser (silver cylinder, top of photo 4) is a typical 9V motor that can be found at a hobby store and can be tested for continuity with a 9v battery due to the PCE Duo's 9V voltage. It's hard to get the dang thing back in, de-soldering the wire is the easy part, just watch those gears. The very tiny screws are aluminum, and non-magnetic so make sure you have a steady hand if you have to replace the motor. I've only seen one go bad, ever so I would bet this is not the issue. Make sure to add some extra White Lithium Grease at this point to ensure your gears stay properly lubricated.



Carefully, and not forcing it, lift the laser cover off from the bottom right-hand corner of the cover, it should click right off, and pull away to the left; always make sure not to disturb the laser or the wires.



Now that we have the laser cover off, we can see what the laser really looks like and what it is connected to. The laser slides across two metal posts that hold it on its track, and it connects to the motor and two gears via the top track which is part of the laser assembly. The HOP-M3 is connected to the motherboard by two ribbon cables; the white connector on the top, and the red connector on the bottom.



Presumably your laser has been returned to the origin position, next to the spindle, like in the next photo. DO NOT UNDER ANY CIRCUMSTANCES, FORCE THE LASER at this point, for risk of harming the fragile plastic gears. Next, very gently; unplug the two connectors (the white first, then the red) applying equal pressure on both sides of the connectors, so you don't harm them or pull a wire off or out of the plug(s).

At this point we must Zoom in again to the right-hand side of the laser assembly, specifically the two black plastic 90degree screws that hold the tracks in place (note: the tracks are not held in on the left side, so be careful when removing them so you don't pull wire or move too quickly).  



At this point the black screws need to "opened" so the laser can be lifted up and slid off the tracks. Using a phillips head screwdriver, turn each of the screws 90degrees CCW.

Now, carefully; lift the tracks from the right side at a very gradual angle (almost vertical at first) to first unseat the track from the gears, and then lift the tracks up and to the left to  slide off the old laser. Remember that on the left side the tracks are in a seat, and not connected to anything.



The New HOP-M3 arrived from Electronix.com, in a sealed blue plastic bag. The price was around $22 plus shipping. The customer service reps were very friendly, and they give volume discounts with the more you buy. Here is a direct link to the laser, don't let the stock photo fool you. If you don't get the correct one they will make your order right.

http://www.electronix.com/cd-pickup-hopm3-p-14472.html



Make sure to use plenty of white lithium grease on the tracks after the re-installation of the new laser, and make sure to lay it down vertically initially as to not harm the gears again. Lube the gears with plenty of grease, and also the arm for the motor, which may be close to dry as well.

Once the new laser is back in place secure the tracks by putting them flat, and turning the black plastic lock-screws 90degrees clockwise. Now that the HOP-M3 is physically installed, clip back in the two wire connectors; red first, white second, applying even pressure on both side while taking care to not to force it, or harm the laser. You should feel a "click" upon successful re-installation of the clips. Make sure they're on there tight.

At this point, your Duo should look like Image #6. Re-install the dust cover for the CD; without it it is very common to get a "Set Disc Error". Angle it downward towards the left top corner, and install that corner first, then apply even pressure while clicking down on the bottom right side. The dust cover should set nicely back into place.

Your Laser is now physically installed.



Provided your Duo does not need a Pot adjustment, You can close it back up. Remember to replace the security bits with the Phillips head screws.
« Last Edit: March 18, 2011, 07:09:36 AM by blueraven »
[Thu 10:04] <Tatsujin> hasd a pasrtty asnd a after pasrty ASDFTERTHE PARTY
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blueraven

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #1 on: November 20, 2010, 12:12:13 PM »
Adjusting the Pots:

Advanced Users/Modders only! (unless you really want to risk it...)

BEFORE YOU TOUCH ANY POTS, USE A THIN PERMANENT MARKER TO MARK EACH POT'S ORIENTATION.

Tips: The main issue is breaking a pot, or putting it so out of whack the CD player won't read discs at all. Be very gentle, and go SLOWLY when rotating the screwdriver, trying for just a few degrees (out of 360) at a time. This is 20 year-old technology and electrolytic fluid my have weakened the traces. VR102 is the place to start. Please reference BMW's photo below before proceeding.

What You will need:
1 Multimeter with Resistance (Ohms)
1 #0 Philips-head Screwdriver
1 Ocilloscope (optional)

Regarding the Trim Pots For the Turbo Duo/PCE Duo and taken from this post:

http://www.pcenginefx.com/forums/index.php?topic=3586.0

These measurement points may help.

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

Charlie

Also, the Duo-R and DuoRX DO NOT have a vr104 pot.

my DuoRX:

vr101:AB=12.33 AC=10.65 BC=19.55
vr102:AB=7.89 AC=8.11 BC=11.28
vr103:AB=7.25 AC=7.14 BC=18.46
vr105:AB=0.38 AC=0.00 BC=0.38


Thanks to BlueBMW for this troubleshooting/repair link and adjustment photo that is very helpful!!!:

http://www.repairfaq.org/sam/cdfaq.htm



Also BlueBMW's guide to adjusting the pots by ear, which is brilliant!

Addendum:  Adjusting the pots by ear!

Adjusting your duo's pot can be a daunting task for anyone.  With the high cost of replacement hardware, none of use want to permanently damage our precious Duos!  Here I will try and explain in idiots terms, the adjustment of the Duo pots.

Preliminary setup:

I do my adjustments live.  Meaning I have the system on and hopefully spinning / reading the disc while I do adjustments.  To facilitate this, I remove the magnet from the CD lid (turn the retainer ring until it releases the magnet)  And then I place a piece of tape or whatever over the lid closed switch.  At this point I place an audio CD on the spindle and place the magnet on top of it to hold it in place.

Adjustment:

I use a small philips screwdriver to turn the pots.  If you look closely at them, they have 4 little notches that a screwdriver fits into perfectly.

Once you have a CD in place and everything is ready to go, turn on the system.  If you don't want to connect your Duo to a tv, you can use headphones instead.  Press the run button on the controller.  If the CD starts spinning.... Great!  If not, we'll start with two of the pots:

VR102 and VR104

VR102 has a small range of adjustment in which the CD will start to spin.  If you turn it and the cd starts to spin, then you know you have found one end of the adjustment.  Keep turning it until the CD stops again.  Once you know approximately where those two points are, you can find a sweet spot in the middle.

VR104 seems to be similar to VR102 in that there is a certain range in which the CD will spin.  Again try and find the sweet spot in the middle of the two points of spin/no spin.

By this point, hopefully you have the CD spinning, and maybe even attempting to read!  So lets move on to the next pot/s.....

VR101 and VR103

VR101 is kind of a by ear pot.  There seems to be a small range that works for proper cd playback.  Typically it seems to be in the 0 to 45 degree range with 0 degrees being horizontal.  You should hear some scratchy funny noises when VR101 isn't adjusted properly.  Try and find a quiet spot for it.  If you go too far it will get very noisy.  Hopefully you can find a spot where the CD audio will start to play.

VR103 is, from what I can tell, an error correction adjustment.  Hopefully you have got a CD spinning reliably at this point.  You might hear a whiney faint scratchy noise at this point.... adjust VR103 clockwise until the noise goes away.  If you go too far, the noise will come back only it will be a lower tone and not sound good. :P  Try and find the sweet spot where the laser operates quietly.

VR105


Lastly, VR105....  This is an adjustment for the spindle speed correction.  I'm not 100% on the best way to describe adjusting this one.  Basically if the spindle speed starts to run away (go REALLY fast) then you've gone too far.  Hopefully by this point, your CD will play music.  Try and play later tracks on the CD and if they struggle to play, try adjusting VR105 until you can play all the tracks reliably.

Hopefully this helps, any suggestions are appreciated!
« Last Edit: April 12, 2015, 08:00:28 PM by blueraven »
[Thu 10:04] <Tatsujin> hasd a pasrtty asnd a after pasrty ASDFTERTHE PARTY
[Fri 22:47] <Tatsujin> CLOSE FIGHTING STREET; CLOSE FORU; CLOSE INTERNETZ; CLOSE WORLD; CLOSE UNIVERSUM
--
Arkhan [05:15pm]: ill brbl im going to go make another free game noone plays lolol

Opethian

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #2 on: November 20, 2010, 12:28:34 PM »
legendary thread! thanks bleu
CAW!

[Mon 16:27] <BlueBMW> i wouldnt sell an unmolested duo hehe.  I molest the crap outta of em before they leave me

Duo_R

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #3 on: November 20, 2010, 01:46:06 PM »
Nice work! Please sticky this thread!
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BlueBMW

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #4 on: November 20, 2010, 02:27:17 PM »
Excellent guide bluebird!   :dance:

« Last Edit: November 20, 2010, 02:44:58 PM by BlueBMW »
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Duo_R

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #5 on: November 20, 2010, 04:48:53 PM »
So what is the risk by adjusting the pots? And some oscilloscope or ohmmeter tips?

Again this is epic!
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blueraven

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #6 on: November 20, 2010, 04:58:28 PM »
legendary thread! thanks bleu
CAW!

Nice work! Please sticky this thread!

Excellent guide bluebird!   :dance:

Thanks Guys, I really appreciate the tips and pointers and I couldn't have done it without the help! It would be awesome if this became a sticky topic. CAW :D

So what is the risk by adjusting the pots? And some oscilloscope or ohmmeter tips?

I just updated the guide with the tools for the adjustments. Just be incredibly careful and make sure the positive/negative tips are clean so you get an accurate reading. I added a few "tips" at the beginning of the thread too, and when I get some oscilloscope readings I will post visual shots.

Again this is epic!

Thank You again, Duo_R!
« Last Edit: November 20, 2010, 05:27:50 PM by blueraven »
[Thu 10:04] <Tatsujin> hasd a pasrtty asnd a after pasrty ASDFTERTHE PARTY
[Fri 22:47] <Tatsujin> CLOSE FIGHTING STREET; CLOSE FORU; CLOSE INTERNETZ; CLOSE WORLD; CLOSE UNIVERSUM
--
Arkhan [05:15pm]: ill brbl im going to go make another free game noone plays lolol

Duo_R

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #7 on: November 20, 2010, 10:11:14 PM »
Just wanted to display a pinout of the pots to make sure we are measuring them the same:




Now I did some readings on my two Duos. My U.S. Duo back in the day had problems and I sent over to Retrogames to have the laser fixed. The guy also said he "calibrated" my laser to better ready CDR's. Compared to all the other Duo systems I have, this one reads anything I throw at it. Compared to my Duo-R and PCE Duo, the CDR capability is superior. Here are the results of reading the pots. NOTE - I tested the laser pot, and both readouts were the same.



So looking at my stats, the only real difference from my PCE Duo and US Duo (that was repaired by Retrogames) is VR105. Everything else is pretty close, and the laser pots read the same. Is VR105 the secret to improving CDR calibrate? Based on this information it doesn't make it seam that way.  :-k

And yes, I am getting a reading of 300 (no decimal) on VR105 for AC and BC measurements.

Quote
VR105

Lastly, VR105....  This is an adjustment for the spindle speed correction.  I'm not 100% on the best way to describe adjusting this one.  Basically if the spindle speed starts to run away (go REALLY fast) then you've gone too far.  Hopefully by this point, your CD will play music.  Try and play later tracks on the CD and if they struggle to play, try adjusting VR105 until you can play all the tracks reliably.


Caution - I am not saying to calibrate your Duo to 300 for VR105, only trying to figure out what the Retrogames guy did to read CDR's so damn well.   :wink:


« Last Edit: November 20, 2010, 10:26:45 PM by Duo_R »
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Duo_R

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #8 on: November 24, 2010, 08:30:32 PM »
Update: ok did another read on VR105:

VR105:
AB: 0
AC:  .300
BC: .300

I am going to blame it on the cheepie ohmeter, looks like it wasn't displaying the decimal there. Not sure about the AB measurement but this is what I am getting now. Ok going to throw away the cheepie ohmeter now. lol
« Last Edit: November 24, 2010, 08:50:07 PM by Duo_R »
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BlueBMW

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #9 on: November 25, 2010, 12:55:06 AM »
Ill ohm out my pots today and see what mine are at.
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Charlie

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #10 on: November 25, 2010, 02:20:59 AM »
VR105 is a 3k (ie: 3000) ohms rheostat, not a potentiometer; it sets the servo VCO.  The spindle speed takes off because you have gone out-of-lock.

Looks like you are measuring the full value, but with the decimal point wrong.  It seems strange that you would get this value, I would expect something smaller...unless the value you are measuring ACTUALLY IS 300 ohms.

Charlie


« Last Edit: November 25, 2010, 02:27:18 AM by Charlie »

chany60126

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #11 on: November 25, 2010, 03:50:00 AM »
It took one long night, but I was successfully able to replace the laser on my duo!  :dance:
It was a long tedious process, but I took the upmost extreme caution to remove those two connectors. It is kind of funny, at first I thought I had to remove the entire white square that was attached to green board of the laser. I later found out that the connector was only part of the white square, as the rest of it is attached to the laser.  :lol:

Once I got that issue straightened out, I saw that I had very little room to work with to grab hold of the white connector as it were so close to those fragile wires. The only tool I had to grab hold of that connector were flat pliers. What I did was that I took one of those small precision screwdrivers, and I started nudging the sides of the white connector forward, alternating on each side, until I had enough room to grip with the pliers. Then I started using the pliers to wiggle the connector back and forth, which took a lot longer than I expected it to. Those suckers are plugged in real tight, but I didn't get too aggresive. After I got the white connector off, the red one was next.

Unfortunately, the red connector was too far low for me to nudge the sides with the screwdriver.  So what I did was remove the laser from the system, with the red connector still attached, and then I flipped the laser over so that I could see the bottom of the red connector. I then took a sewing needle and started pushing the red connector forward from the bottom through each of the ~six gaps. I did not even have to use pliers to remove this one!

The only hiccup I had, was that one of the two bars that hold the laser in place became unglued. But the system seems to work fine as the bar seems  securely fastened with the screw in place.

Before I start partying like it's 1999, I will test out the system extensively after thanksgiving. But when I did a test run of about 15 minutes, everything seemed great.

This is the first tekkie repair i've ever done, so it's a real confidence booster. But I won't be soldering anything anytime soon. One small step for Chan, one giant step for my Turbo Duo. :)

Thanks to everyone on here that contributed to this awesome laser guide. And also for those who had the patience to answer all of my questions in the shoutbox. You guys are awesome.   

« Last Edit: November 25, 2010, 08:08:15 AM by chany60126 »
SignofZeta: What a quintessentially PCEFX thread. Someone complains about nothing, multiple Bible-length posts discussing who's a bigger a$$hole follow. You're both pretty big a$$holes. Let's call it a tie.

blueraven

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #12 on: November 25, 2010, 07:30:32 AM »
VR105 is a 3k (ie: 3000) ohms rheostat, not a potentiometer; it sets the servo VCO.  The spindle speed takes off because you have gone out-of-lock.

Looks like you are measuring the full value, but with the decimal point wrong.  It seems strange that you would get this value, I would expect something smaller...unless the value you are measuring ACTUALLY IS 300 ohms.

Charlie

Thank You very much Charlie, this trim pot has been a point of question for me for the last few months, specifically what it's exact function was... Your expertise and input is invaluable!

Update: ok did another read on VR105:

VR105:
AB: 0
AC:  .300
BC: .300

I am going to blame it on the cheepie ohmeter, looks like it wasn't displaying the decimal there. Not sure about the AB measurement but this is what I am getting now. Ok going to throw away the cheepie ohmeter now. lol

Thanks you for the updates, Duo_R and BMW, I appreciate the follow-up!

It took one long night, but I was successfully able to replace the laser on my duo!  :dance:

chany, I'm glad it went well! Congratulations!

I'm glad the connectors didn't give you any heck, sometimes they can be fragile, I overstated this a bit to stress the fragility of the wires. good call on the needle.

Already a satisfied customer :mrgreen: Enjoy Your Duo!
[Thu 10:04] <Tatsujin> hasd a pasrtty asnd a after pasrty ASDFTERTHE PARTY
[Fri 22:47] <Tatsujin> CLOSE FIGHTING STREET; CLOSE FORU; CLOSE INTERNETZ; CLOSE WORLD; CLOSE UNIVERSUM
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chop5

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #13 on: November 25, 2010, 08:53:34 AM »
Excellent thread. I made some crude pictures about taking off the connectors from the laser if they are any help to anyone:

http://img.photobucket.com/albums/v238/jetbue7/duolasercordpic2.jpg

http://img.photobucket.com/albums/v238/jetbue7/crudedrawingoflaser.jpg
AKA jetblue
Gentlemen behold...The chopsado!
http://img.photobucket.com/albums/v238/jetbue7/prchopsado.jpg tg-16 region converter or some weird bow tie

Platinumfungi

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide
« Reply #14 on: January 21, 2011, 05:36:15 PM »
Another invaluable resource to the NEC community! Great job  :clap: