Image Map Image Map
Results 1 to 5 of 5

Thread: Northstar Horizon motherboard & PSU schematic

  1. #1

    Default Northstar Horizon motherboard & PSU schematic

    Folks,

    I have searched but can't find a circuit diagram/schematic for the Nortstar Horizon motherboard and PSU.

    Con someone point me in the right direction please ?

    Something went 'pop' on the motherboard on power up yesterday (in the regulators location) and the unit no longer boots from disc - although it powers on just fine and all the main supply voltages seem fine. I can't see anything blackened on the board so need to start tracing.
    Thankfully the CPU, memory and disk controller cards are all ok as I have tested them in one of my other machines.

    Thanks in advance.

  2. #2

  3. #3

    Default

    Quote Originally Posted by deramp5113 View Post
    Spot on - thanks Mike.

  4. #4

    Default

    Usually its the tantalum capacitor behind the 78L12 regulator see: http://www.connect.gi/northstar.htm

    It means taking out the motherboard and carefully removing the remains and replacing it.

  5. #5

    Default

    Thanks for the tip - I'll take a look again this weekend.

    As I said all the supply voltages seem fine - including the 12v and 5V supplies to the drives. I had assumed that perhaps as the flash was from the mainboard it had knocked out some of the logic on the mainboard. Having reviewed the schematic, there is actually not a lot on the mainboard that would affect CPU operation as most of the circuitry seems to be for the port I/O - other than clock generation ?

    Quote Originally Posted by jimwatt View Post
    Usually its the tantalum capacitor behind the 78L12 regulator see: http://www.connect.gi/northstar.htm

    It means taking out the motherboard and carefully removing the remains and replacing it.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •