Duo System with Faulty Hu Card (Bad Trace)

[Slypty]

    A Duo I tried having repaired by a friend re-capped the entire system, and it boots up OK and the CD works, but Hu Cards won't load.  He has cleaned the slot and says it is fine, and thinks there's a broken trace somewhere on the Hu Card reader.

  Is there a pin out or diagram of how to check for continuity from the Hu Card to the underside of the Duo?  It would suck to have to find out which pin goes to what, and would make the work thousands of times easier to know which pin goes where.. anybody have a link for this error?  Thanks

[MobiusStripTech]

Did the Hu Card slot work before? If so your friend should probably be looking into this for you. Did they show you any pictures of damaged traces?

[Slypty]

It was bought as is/untested.  My friend is a technician who has worked with video games for 10 plus years, and can usually turn a garbage pale in to gold.. so I trust his knowledge enough to rely on the problem he diagnoses. 

  If he knew where the damage trace was, that would be different.. finding which trace runs where from the top of the Hu Card slot to the bottom, is a massive mess with out a diagram..

  Really just need a schematic if anybody knows how to get hold of one?

[Pokun]

I haven't seen a lot of model-specefic schematics but there is a general one in the Turbo-Grafx-16 Service Manual that is floating around on the internet.

[mickcris]

Just turn it upside down.  The traces are easy to see.  Just use where the slot is soldered to the board instead of the slot on the top

I don't think there are schematics available

[Slypty]

Thanks, I'll give this a go tomorrow.  Maybe schematics aren't that necessary, hopefully I can find the problem.

[thesteve]

if all cd games work, i would be looking at the card detect pin, and the bus control circuit (IC520)
generally if IC520 is bad it wont load anything, but on open trace on its control pins could likely cause this
use the TG16 schematic, as that covers the hu card circuit, just not the CD side (note cards will run with IC520 removed, allowing you to test the basic system without the CD hardware in play