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Turbo Duo CD-Rom issue

Started by jarryson, 06/12/2018, 01:14 PM

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jarryson

Hi all,

I am new here, thanks to admins for activate my account. This is my first message .

I have a Turbo Duo, it was stored in a box since years...and I decided to check it because I bought a turbo everdrive.

I made the rgb mod, and its working fine. I recapped all caps too, sound is working fine now with hu-cards.

But I have a problem in cd-rom. I dont know if lens works. When I turn on the console, cd spins all time. I am not expert in Nec consoles, but this console has a push button which is pressed when cd tap is closed, right?
In my console this push button dont mind, cd spins all time. I have tested the push button and there isnt continuity, so its fine.

Lens is always in the same place, motor which moves the lens has 4V, I dont know if this is correct. I have tested traces and all is ok too.

Sorry for my English, I have recorder 2 videos. I have only a cd-r burned at 1x and a music cd to test cd-rom drive.

https://www.dropbox.com/sh/xzop8o1qrddkall/AAAgpc-3mA2gWsixr60tET2ua?dl=0

In my dropbox folder there is a pic too. In this pic, as you can see, I have replaced a 220 Ohm resistor because there was continuity. I have continuity in L101 too (in his extremes).

If anyboy can help me...

I have only a tester, no osciloscope or similar.

Thanks in advance.

Keith Courage

Check for old cap leakage around the two 47UF caps next to the CD loading light. You might need to repair the connections for those caps+check the Via holes nearby to make sure there is continuity.

jarryson

Thanks for reply, caps were replaced and I dont see any bad trace, so I think this console hasnt solution.

un1qu3

#3
Hate to bump, but I'm having the exact same problem except on a PC Engine Duo.

I've checked every trace around the LED and I've even tried replacing the CXA1082B thinking that might have gone bad, to no avail.

Essentially, both the laser motor and CD spindle turn at full power when switched on regardless of the console lid switch's position. I can't see any particular traces that have been damaged and am getting continuity through to both sides of the board as far as I've tested.

IC109 (the top BA6290A) gets extremely hot within a few seconds of switching on the console, which I attribute to both CD unit motors going nuts. If I disconnect the CD unit motor loom, it doesn't heat up at all. I have a couple of replacement BA6290A's on order in case those are the issue, but I somehow doubt that's it.

I've done a capacitor swap to the entire console and the HuCard side works flawlessly.

Anyone have any additional thoughts or things I can try? I have access to a scope and multimeter.

un1qu3

On a whim, I pulled IC107 and noticed a ton of corrosion underneath the 4558. Vias were totally eaten away, so I ran a couple of jumper wires around to the other side for pins 6 and 7, and now the CD drive, while it still spins with the CD door open, runs at about half speed, and the laser, which had been moving and sticking to the center of the drive, runs to the outside of the drive and sits in place.

I guess it's a step in the right direction. I'll keep looking for more bad traces or vias in that area of the board.

thesteve

what KC said was correct
there are 2 huge traces that run across the front of the unit sending 5V to the CD system
the VIA near the 47uf caps by the LED gets eaten away and you lose 5V to the chips causing this issue