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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: schweaty on December 16, 2016, 09:38:14 AM
Title: Super CDROM CD player malfunction
Post by: schweaty on December 16, 2016, 09:38:14 AM
Gents,
I picked up a broken Super CDROM with absolutely no sound. Everything else, including the CD player itself worked fine, just no sound. I ran it through the dishwasher and did a full recap. Now I have sound. Yay! But now the CD player won't play discs. Here's what is happening:
It will spin, the laser will start to read the disc, then after maybe 2 secs the screen will dim slightly and it will start all over again. It will keep doing this until I turn the power off. It never gets to the "please set disc screen". I have messed around with the pots a bit, but there is minimal change. There also isnt a guide for tweaking the pots on a Super CDROM, so I have been going off the Duo guide for now.
It seems like it is getting to a point in the early sequence (logic sequence?) and then failing a test and starting all over or something. I don't have an oscilloscope or even know how to use one so that is probably out.
Any help is appreciated. This is really frustrating because the damn thing was working before I "fixed" it.
-dan
Title: Re: Super CDROM CD player malfunction
Post by: SignOfZeta on December 16, 2016, 12:31:04 PM
If the screen dims, the TV screen, when the drive is running then you are outstripping your power supply. The PSU is inadequate (these systems need at least 850mA, 1000 or more recommended) or you have a massive current draw. A dead short or mechanical binding somewhere.
I think the drive is losing consciousness, basically. It's old. It stood up too fast.
Title: Re: Super CDROM CD player malfunction
Post by: schweaty on December 18, 2016, 05:40:03 AM
Ok... so the playing problem was fixed with the cap thesteve talked about in the cap replacement thread. but now i'm getting consistent the same graphics glitches on CD games ONLY. hucards play just fine. here are some pics and a short vid of Gate of Thunder because i could capture the glitch with a pic. maybe a vid ram error? any help is appreciated.
Riot Zone (http://i.imgur.com/Fgs5BDJc4ca.jpg?1)
Ys Iv (http://i.imgur.com/FnSCZMo.jpg)
Title: Re: Super CDROM CD player malfunction
Post by: schweaty on December 18, 2016, 08:40:36 AM
as always, thesteve came through. it was the shitty chinese power supply mucking up everything. now its developed a low volume problem.... frustration.
Title: Re: Super CDROM CD player malfunction
Post by: SignOfZeta on December 18, 2016, 11:48:31 AM
Was the power supply you replaced it with *not* Chinese?
Title: Re: Super CDROM CD player malfunction
Post by: esteban on December 18, 2016, 12:07:22 PM