Zenith SuperSport 286e

Resources

Wiki
Vintage Computing and Gaming
ZDS Parts (archive)

I have not found any user nor service manual. If you have one, please let me know.

Internals

Motherboard

Pressing ESC during boot enters MFM-200 command line debugger that is contained in ROM. BIOS settings can be changed with SETUP command.

Display

LCD

Display Controls

Backlight

Power Supply

Keyboard

Floppy Disk Drive

Hard Disk Drive

My Supersport came without any HDD. I tried installing Compact Flash IDE drive emulator, but it did not work – it caused the display to be malformed. What works fine with this machine is a commonly available SD card IDE drive emulator. No tricks are needed, just connect it as use as an internal hard drive.

Reassembly

Fixing Backlight CCFL on ZenIth SuperSport 286e

Display backlight was broken on my machine. The power supply module located in the laptop base is responsible for producing the voltage for the CCFL lamp in the display. A transformer that was part of that circuit was damaged. CCFL is served by an integrated hybrid circuit called TSHIC-CCFL2. This chip produces waveforms for T301 transformer, which secondary winding is connected directly to the CCFL lamp. TSHIC-CCFL2 circuit is powered by +12V from the power supply and is enabled by +5V signal fed from the motherboard through Q301 transistor. Additionally, the brightness potentiometer in the display base is connected to the circuit for backlight brightness control.

The CCFL circuit can be replaced by a modern universal laptop or monitor inverter board, for example GYT-DK0205.

Original TSHIC-CCFL2 and T301 as well as Q301 can be removed from the power supply board.

The inverter board can be connected to the +12 and GND pins of former TSHIC-CCFL2 and directly to +5V control pin on the motherboard connector. The brightness control can be probably also adjusted to the new board, but I have not tried to do that. Connecting the brightness pin on my inverter board to ground makes it work on highest settings and I see no reason to adjust it.

7 thoughts on “Zenith SuperSport 286e

  1. Hi and thanks for the article,

    I have a pdf of both the owner and user manual for the ZDS supersport. My bet is that the information in the two manuals are identical to the information in the Supersport 286 manuals. Shoot me an email if you want a copy.

    Will

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  2. Hi Pawel,
    Another fantastic page for others trying to fix these old computer. Thank you very much.
    You clearly have very good electronics and documentation skills and you put them to good use :o)

    Some questions, if you don’t mind :
    1. How did you format the SD drive ? fat16 ? partition size ? from dos6.22 ?
    2. For the SD-2-IDE card, what did you set the disk type to in the BIOS ?
    3. How many disk options do you have in your Zenith BIOS ? mine has 50.
    4. What are the red and blue wires going to the SD-2-IDE card ?

    Thanks
    Ian.

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    1. Thanks Ian! I used DOS 6 to partition the card with fdisk and then format it. Then you can move the card to a PC reader and save files.
      You can set up any BIOS option that offers smaller capacity than the card. The parameters will be likely ignored by the reader and just used for calculation of the sector number. I don’t know how many disk options I have and I can’t connect it at the moment to see. I can check it over the weekend.
      There is a IDE 40 pin (laptop uses that) to 44 pin (card reader uses that) adapter attached to the card reader. The blue and red cables are for +5V which is missing in the 40 pin connector.

      Like

  3. HI Pawel,
    Thanks. I’ve ordered the parts for the CF to IDE disk adaptor and will use your advise for that.

    One more thing if you don’t mind. I was using the machine today and all of a sudden (nothing special happening, just using dos) the blub light went RED and it turned out that the fuse in the power brick blew. I replaced it with another fuse but that blew too, although that blew without the computer attached so im guessing some shorted in the power brick itself.

    Now my machine boots up fine (using bench power supply) but I don’t see any text. The back light (and the slider) is working fine but the contrast slider does not work, maybe because I have no text on the screen. Even though i can’t see the text, the machine boots up good and starts ms-dos and when i run a (blind !) dir , the floppy disk seeks fine.

    So the screen/text is not on but everything else seems to work. I can’t connect the CGA output at the moment as i dont have a CGA cable but i would guess that would be fine too. i’ll see if i can get a cable.

    as you had so much experience with the power supply on this i thought you might point me in the right direction.

    thanks
    Ian.

    Like

  4. Thanks for an amazing article. I’ve had a bunch of old /nostalgia pieces myself but haven’t shared the details as well as you ahve in this case.

    Many thanks for contributing to lost knowledge.

    Like

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