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

[bishopcruz]

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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Yeah, opened her up, didn't realize just how much force was going to be needed to spin the gear, the rails seem lubed up and clean already, which is nice, now to mess with the pots. Which pot is it for audio cutting out on a bad read?

[thesteve]

Vr104 is focus, Vr103 is focus comp
Vr101 and Vr102 are tracking
Vr105 is spindle comp
Crackle is either focus or tracking
Spindle comp will cause early or late track issues

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[bishopcruz]

Vr104 is focus, Vr103 is focus comp
Vr101 and Vr102 are tracking
Vr105 is spindle comp
Crackle is either focus or tracking
Spindle comp will cause early or late track issues

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Any tips for getting the spindle pot working again? I had everything just about perfect then my hand slipped while dealing with vr 105, now I can't get it to read discs anymore, I've been using small increments, as I did with the other pots, but nothing, I'm hearing a clicking, which I assume is the gears, and a high pitched whining at times as well. I wasn't hearing the whine before I screwed up on 105.

[thesteve]

Slipped?
Did you hit something with a screwdriver?

If not center the pot and try again
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[bishopcruz]

Slipped?
Did you hit something with a screwdriver?

If not center the pot and try again
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TUrned a little bit farther than I expected. Not TOO far, but clearly enough.

[thesteve]

The pots spin all the way around without breaking
Just spin it back


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[bishopcruz]

The pots spin all the way around without breaking
Just spin it back


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That's what I did, it's just refusing to work now, was at it for hours last night.

Appreciate the help though.

[bishopcruz]

Welp, got it working again, it's still giving me hell on a few of the burns I have, but at least my physical games are working. I may open her up again once I am done with a couple of my regular games and see if I can get it working a bit better with burns. The fix, messing a little with VR 102, which I hadn't touched at all for the whole experiment. No idea why that worked, but it at least got me back to being able to read an audio CD, and was then able to follow BlueBMW's tips and even got my scuffed up YS III working, the music in the mines is no longer cutting out on that one at least.

[bishopcruz]

Ok, ready to do what will hopefully be the last adjustments I will need for the pots. Mainly to see if this thing will read CD-Rs well (The discs I burned worked great on Irish Ninja's DUO-R once we got it working. But either won't load, or audio cuts out on mine.) I found an older-ish multimeter to test the resistances, but it is manual. The question I have is that there are several settings for resistance on the thing. It starts at 200ohm, and then goes to 2000, 20k, 200k, and finally 2000k. What should I have it set to to measure the pots? Also, since I'm measuring resistance, it shouldn't matter which color goes on which point correct?

Yeah, this is fairly noobish, but I haven't done much electronics work since around my first year in college and I am rusty as all hell.

[IrishNinja]

The discs I burned worked great on Irish Ninja's DUO-R once we got it working.

well, that's not true at all, is it?  why, i went to boot up my 3-in-1 and Grand Master Meio killed me good. 

[Zer0-2k11]

Hey everybody,

First poster here, loving the contents of the forum so far. Hope i can contribute to the forums as much as i can.

I recently received my first PC Engine Duo the other day from eBay but it had audio issues and a full recap has seemed to fix the issue  , but now i got a bit of a problem now with the CD drive. I didn't have any original HuCards or Super CD games on hand so i decided to give a backup a try and the system wasn't reading it well and would boot the game 1/10 times. Afterwards i went to try to make adjustments in small increments with the pots on the motherboard but in the end, i stupidly turned all the pots a good bit and lost track. I normally would busted out my multimeter and used the charts to listed in the first few posts to get back to somewhat normal readings again but i dont know what the 2nd post means by "AB" "AC" "BC". Does anybody what this means?. I have done Gamecube pot adjustments and it was just a simple ohm reading. My multimeter is giving problems so i have to wait intill my next paycheck to get a new one (BK Precision) and also get a new HOP-M3 just in case, but i figured i would ask the necessary questions beforehand so i when i get the multimeter and the new laser, i can know before hand and it bring it back to life and get it running like new again. Can i still revive this PC Engine DUO or is it screwed? .

Thank you everybody for their time and patience.

[thesteve]

you cant kill anything by turning the main board pots
the pot on the laser can damage the laser

[Zer0-2k11]

Thank you thesteve,

I managed to get the CD drive working again using a retail disc of Eden of the East. I got CD drive working again by replacing the laser and using the values noted in the link on the 2nd post. I used the last few posts in that thread. I used the DUO-RX readings then used the VR104 value on another post. May need more turning to play CD-R's working but i got audio issues again . Got to fix that first. 

[Ripthorn]

Hey guys, first post here.

I want play the Castlevania fan translation, so I ripped my original disc and then I applied the patch.

Burned in 10x (minimum possible speed) and tested on my original Duo.
No problems with gameplay, just the audio tracks that play a bit and then stops. Sometimes the Richter  sprite appears garbaged.
The original disc plays without problems, the translated version plays without problems on emulator.

So that means I need to replace cd lens?
Calibrate pots?
Use other cd brand (tried two)?
Change caps?

I would appreciate if someone could help me.

PS: Sorry for my bad english.

[Tempest_2084]

Hi,

I've just completed the laser replacement and everything went very smoothly (or so I thought).  However no matter what I do the CD will not spin and eventually I get a Set Disc error.  I did a basic continuity test on the wires and they all seem good at least I think.  On a hunch I put my old laser back in and it also will not start spinning the disc. 

Since both the old and new laser don't seem to be detecting the disc I guess I must have broken something when I removed the laser.  I can't see what I could have damaged as it was very simple and I followed the guide.  Any ideas?