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

[Keith Courage]

So the disc doesn't spin up anymore now even though the lens bobs up and down? Could be a bad lens but this is also a symptom of a bad BA chip. They are the large ones just below the CD drive.

[TorqueEmPup]

I mean it kinda spins, but only slightly when the laser is trying to lock onto the disc. But it's acting like it can't see the disc at all.

I'll go ahead and record a video to show what I am talking about.

EDIT:
Here we go.

[Keith Courage]

Based on that video I would try the BA chip. Farthest bottom right corner of the board. I think there is just one in the DUO-R as opposed to the two large ones in a regular Black DUO.

[TorqueEmPup]

lovely...

I don't have the proper tools to swap out surface mount parts. =/

Though I find it weird, because if it was truly faulty, why would everything else be working with the drive? The sled motor will return the laser to center, the laser has power and is attempting to focus.
And with the drive assembly that came with the system with a burned out sled motor would cause the spindle motor to spin very very fast.

Also the disc will spin for the duration it takes the laser to return to center. But once it returns to center the disc stops.

Doesn't the BA chip control just drive the motor functions?

It seems like the BA chip is doing it's job.

It's more like the laser isn't seeing anything there.

[Keith Courage]

The BA chip is the power driver for the CD lens(not the lens motor). So if it's not working correctly, then the lens won't read anything. Another symptom of a bad BA is the disc spinning but games won't load.

https://datasheetspdf.com/datasheet/BA6290A.html

The issue could be capacitors or a faulty trace in the CD chip function portion of the board but it's extremely rare for caps to go bad on a DUO-R. You can always try to poke around for a faulty trace or connection on the board.

Someone obviously got rid of the DUO because they couldn't find the problem(new capacitors already installed). So it's probably a bad trace or a faulty chip.

[TorqueEmPup]

Yeah, new laser came. Installed it and same issue unsurprisingly.

I'm curious where the large wire goes on the white connector. as that's the only wire of that size, and it goes into a bundle with other wires, but doesn't come out on the laser side.

What is this wire for? as I'm not finding it has continuity on any of the wires on the laser side of the connector.

[Keith Courage]

Pretty sure it's just a ground shielding thing. So it doesn't actually go through to the other side.

[djcaye]

Hi everyone.

I am new with PCE Duo; Mine has a problem that I can´t solve it. I read all the post and do not find similar issue. As soon as the console turn it on the cd motor starts to spin backwards (not pushing run button). I try with different motor but happens the same.

Anyone with the same problem??

Regards.

[Keith Courage]

Has the DUO had its capacitors replaced yet? This sounds like a bad trace caused by old capacitor leakage. The area is probably near the CD loading light. There are two 47UF capacitors there. Just to the right of the two 47UF capacitors is a largish hole that can sometimes get filled will old cap goo. Clean and then solder in a old capacitor lead or wire to each side of that holes connection to fix it.

[djcaye]

Thank You So Much for your reply.

I had change the 3 capacitors (2 X 47uf and 22uf) closer to the red led,  also clean this tracks (2 unfortunately are nude in some parts), but I do not find any hole (bigger than the others).. the negative pad of one of 47uf capacitors "jump" (I mean, is out almost complete);Anyway,  I solder it in a small rest of this pad, but, maybe I have to find another negative place to solder the negative point of this capacitor.

Anyway, I clean this surface... but the problem still happen... so I think the problem is more complex..

Regards and again thank you.

[delucep]

Is there a recommended replacement for the pots, the v105 is knackered on this one I?m looking at, think someone has been playing with it too much, it?s definitely gone as it?s just turning.