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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: mbt20251 on June 21, 2012, 07:34:58 AM

Title: Interface Unit w. CD-Rom² problem
Post by: mbt20251 on June 21, 2012, 07:34:58 AM: Hey there,

I recently managed to buy a interface unit with a CD-Rom² sans cables rather cheaply. I bought a universial AV in order to get it running specs are 9V and 1050 mA. Load times however have been really poor. The laser is moving and games start but only after about 2 minutes or so of loading time and then there's missing game music. I get sound effects but none of the CD tracks play. So far I have tried CD-Rom and Super CD-Rom games and the outcome is the same. What's most strange to me is the fact that when I use the interface unit to read reguals CD's it starts playing the music immediately.
I'm kind of lost here so if you happen to know what might be the issure here I'd really be greatful.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: Keith Courage on June 21, 2012, 01:08:20 PM: Sounds to me like either the lens is old and tired, may need cleaning, or even potentiometer adjustment. Try cleaning the lens first since that is the easiest thing to so. Dip a q-tip in rubbing alcohol. Wipe the rubbing alcohol around on the lens for a little bit. Then use the opposite dry side of the Q-tip to wipe it and dry it off.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: incrediblehark on June 21, 2012, 04:16:07 PM: adjusting the pots might solve your problem, thats how I got mine working.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: mbt20251 on June 22, 2012, 06:18:44 AM: I'll try the rubbing alcohol tomorrow and report back if that has solved it.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: turbokon on June 22, 2012, 07:02:25 AM: Or could be the middle gear issue.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: mbt20251 on June 23, 2012, 01:53:04 AM: It's not the middle gear issue since I have opened the unit and checked. Rubbing alcohol dind't help either sadly.
I guess I'll have to adjust the potentiometer then. Can anyone point me in the right direction? I SOL here.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: incrediblehark on June 23, 2012, 03:22:43 AM: There will be I think 4 or 5 of them (been a while) and they look like screws labeled vr101, 102, etc on the board. Make sure you mark the original positions of the pots before doing any adjustment. Then I would say try adjusting a quarter turn or less at a time, and trying the cdrom out, repeating as necessary. there are actual values that each are supposed to be, if you check the duo laser adjustment repair guide you can find all of the technical info. From my experience, I had the most luck adjusting vr101, and to a lesser extent vr103. for me vr101 had the most effect in getting my discs to play.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: Keith Courage on June 23, 2012, 08:04:24 AM: I would try VR102 and VR105 first. 102 is for the lens gain and the slightest adjustment one way or the other could get it working again. I can't remember what 105 is but for some reason turning it counter clockwise can fix read issues on some drives.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: Charlie on June 26, 2012, 09:49:42 AM: I am a bit confused here. Is this the standard IFU that has a CDROM that sits on top of it, and plugs into the back of the turbo grafx?

If so, I don't understand why, when you are using a 9v adapter on a unit that needs, at an absolute minimum, 10.5V (and actually expects about 13V)...and it doesn't work properly....that you wonder why.
If this IS the IFU that I believe we are talking about, the input jack is clearly marked 11V. I would change the adapter first, long before I even thought about adjusting pots.

Or, is this a different unit entirely??

Thanks for any assistance.
Charlie
Title: Re: Interface Unit w. CD-Rom² problem
Post by: Arkhan on June 26, 2012, 11:01:15 AM: Yeah if this is a Black US RoundEye Turbo Grafx CD interface unit, you need a beefier power brick.

You're probably doing the equivalent of trying to play oregon trail with 1 Ox pulling your wagon..
Title: Re: Interface Unit w. CD-Rom² problem
Post by: Keith Courage on June 26, 2012, 01:39:16 PM: Oh I didn't even read that part before. When I read IFU I thought this was for a white PC engine briefcase setup. If this is the black unit for a turbo grafx it needs 11V at about 1500MA so the adapter you have will not work. I have some spare 3rd party ac adapters that will work for you. PM me if you want to buy one.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: mbt20251 on July 06, 2012, 10:36:56 AM: It is the white briefcase unit marked 9V 1140mA.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: Frank_fjs on July 06, 2012, 02:34:55 PM: Ideally you want a PSU that outputs at least 1.5A, 2A would be better though.

I don't think that this is your problem though, sounds like your CD lens may be worn out or in need of adjustment.

There is another slight possibility, and that is that your IFU is faulty. I received a faulty IFU once, and whilst it worked to an extent CD games always took ages to load and the music stuttered. I thought my CD-ROM2 unit must be faulty, but upon connecting it to a different IFU it worked perfectly.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: Keith Courage on July 06, 2012, 03:01:57 PM: Yeah, the white briefcase setup requires 9V 1450mA.
Title: Re: Interface Unit w. CD-Rom² problem
Post by: thesteve on July 06, 2012, 07:37:35 PM: lol they just use the same transformer if 100V in = 9V out 120V in =10.8V out (11)