REPAIR GUIDE - TurboDuo/PC Engine Duo/R/RX: Laser Swap & Adjustment Guide

[Nec.Game.head]

This repair guide rocks! It took me a few days to finally feel comfortable enough to start messing around with the pots on my Duo-r and it totally worked .. No more losing audio at random times .. And it even reads the few cheap quality cdr's I have even better then before .. All it seemed to really come down to is once you find your audio cut out points clockwise and counter clockwise you place a piece of tape on both sides of were it cuts out your audio and center your pot right in the middle of that .. You can always fine tune it after that until you feel satisfied with your adjustment results .. Just be sure to make a tiny little mark on your pots and the board before starting your adjustments, so that you know exactly where they were positioned originally just to be on the safe side .. Thanks a million you guys for contributing all this useful information!

[rCadeGaming]

Just wanted to say that I used this guide yesterday and got great results as well.  The only thing is, while adjusting VR101-105 perfected some games, others still had problems until adjusting the pot on the side of the laser, as others have mentioned.  More info here:

http://www.pcenginefx.com/forums/index.php?topic=14064.msg281184#msg281184

[Chester77]

My Duo R recently stopped reading all CD media types.

I have taken measurements at the pots and tried adjusting them to settings specified in this thread but I cannot get even close to the values specified here.

as an example:

VR101:
GOAL:   AB=12.33 AC=10.65 BC=19.55
ACTUAL:AB=12.0 AC=10.2 BC=10.5

As you can see the BC value is only half of the value we are expecting.
I can adjust the pot to get somewhere around 20 for BC but then the values for AB and AC are all out of whack.
I worked on it for hours and could not dial in the right settings.

I have ordered a new laser unit because it can't hurt to have a new laser but I don't think that will solve my problem.

The power supply is the original A/C power supply that came with the system.

Could bad caps be the cause of this? I don't see any obvious issue with the caps.

If it is believed to be the caps... how do I test them and where do I find replacements?

Thanks!
 

[thesteve]

caps are unlikely
yours has a different value pot most likely
your best start point is set how it was working
look for issues with binding first, before trying to adjust pots

[Chester77]

caps are unlikely
yours has a different value pot most likely
your best start point is set how it was working
look for issues with binding first, before trying to adjust pots

Thanks for the reply.

If I position the unit all the way to the right before power on the unit works it's way inward with no visible impedance after applying power.

I was able to adjust the pots to the pot where the disc spun the entire time between "press run!" and "set disc" but it never actually accepted a disc.

I will try a new laser unit when it arrives.

 

[IrishNinja]

hey all! 
i bought a Duo-R off a popular ebay seller but am also running into the "CHECK DISC" or whatever error, i bought a power supply from retro game cave so it's not that...seller says i need to tighten a resistor and linked to this guide http://homepage3.nifty.com/moremaco/slv.htm, even sent me a minus screwdriver which was really cool.  a search brought me to this helpful guide as well.

problem is, VR102 looks...damaged?  i don't see how said screwdriver will catch, i'm grabbing a # 0 phillips head tomorrow but i'm hoping this pic illustrates the problem:

what can i do here?  it showed up like this and i'm not certain if i have enough on the side to maybe catch with a pair of needle nose pliers and adjust that way, or should i try to remove it & replace with something else (assuming that's even an option)? or is it supposed to look like that?  appreciate any help i can get here. 

it's tricky too cause that guide says i cant unplug the short cable on the right side, but there's a short one on the left too that connects to the region switch installed on the hucard slot, i don't think i can remove that either so we're kinda having work around it. 

[thesteve]

thats how the pots look
look for other reasons first

[BlueBMW]

Also, are you running burns or originals.  These systems have a really hard time reading burned discs.

[IrishNinja]

thats how the pots look
look for other reasons first

yeah?  it just looks a bit off...okay, guess that's how its supposed to be?
or were you referring to another post?

Also, are you running burns or originals.  These systems have a really hard time reading burned discs.

trying original discs, just "PLEASE SET DISC" error previously mentioned in this thread, so far

[Chester77]

Ok, my problem has been solved.

In my experience DUO-R do not have a hard time reading CD-R. I was having trouble with CD-R and originals.

I say in my experience because between me and my brother we have 3 of these units.

I purchased a known working DUO-R from ebay (from japan) last week and it arrived today. Coincidentally so did my replacement laser unit (also from ebay).

I had borrowed my brother's DUO-R and over the weekend and tested all my discs on it. No errors or issues playing an disc.

I tested my new DUO-R from ebay and found the results to be the same. Perfect.

I did not want to open his unit because it is working properly and it has a region mod switch and I didn't want to disturb anything.

I opened the new DUO-R and measured the pots. The results are as follows:

VR101
AB:10
AC:9
BC:15

VR102
AB:8
AC:10
BC:12

VR103
AB:6
AC:14
BC:15

VR104
AB:7
AC:10
BC:15

VR105
AB:.5
AC:0
BC:.5

I replaced the laser on broken unit and tuned the pots as close as I could get them. The replacement of the laser unit was unbelievably easy. I couldn't believe it literally took 30 seconds.

The results for the pots were as follows:

VR101
AB:9
AC:10
BC:14

VR102
AB:8
AC:8
BC:12

VR103
AB:4.5
AC:14
BC:14

VR104
AB:15
AC:7
BC:10

VR105
AB:.5
AC:0
BC:.5

The result.... I now have 2 perfectly working DUO-R systems. The inside of the unit from ebay is extremely clean and the hu card slot seems to work perfectly as well.

I guess I will sell one now.

I paid $335 with shipping.

A reasonable offer would not be refused. If anyone is looking for a system.

Thanks for the suggestions, and I hope this info is helpful.

[thesteve]

fact is the duo and duo-r have the same drive and with the same laser will read equally well on CDR and originals
that said i have seen more marginal parts on the duo vs the duo-r (likely because its older)

[Chester77]

fact is the duo and duo-r have the same drive and with the same laser will read equally well on CDR and originals
that said i have seen more marginal parts on the duo vs the duo-r (likely because its older)

I can only speak of what I know. I only know about the DUO-R.

I didn't make any comment about the DUO or any other variant.

[Chester77]

what can i do here?  it showed up like this and i'm not certain if i have enough on the side to maybe catch with a pair of needle nose pliers and adjust that way, or should i try to remove it & replace with something else (assuming that's even an option)? or is it supposed to look like that?  appreciate any help i can get here. 

It looks very damaged.

Take the measurements (if you can) with an ohm meter. Compare them to the measurements I posted.

If they are similar you may want to try a new laser unit.

Adjustment is very fine and needle nose pliers might not do the job. You need to turn just a fraction at a time.

[bishopcruz]

Ok, my CD laser appears to be stuck, all the way on the outside of the track on my OG PCE Duo. The CD won't spin and I tried moving it back manually, and it seems quite stuck. Am I going to have to open her up in order to get everything working I assume?

Also, in some games, especially burns, the audio would randomly cut out, though this did also happen on some of my old retail games that had scratches. I assume I need pot adjustment.

Finally, someone mentioned I need to lubricate the gears on my Duo, I saw something in the OP about lubricating the rails, but nothing about the gears themselves (unless I missed something) What isthe procedure for that?

[thesteve]

The og duo can get stuck like that any time its having read issues
You will need to open it and spin the motor gear

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