N* Horizon Motherboard Repair
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by Bill Degnan - 12/07/2008 19:57 |
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Power leads on Northstar Horizon Motherboard
see page 31 of manual "Horizon Computer System Double Density" through page 37. Power Leads reset - grey (thinnner) GND - black (thinnner) -16V - yellow GND - black from 11,000 uf cap. +16V - orange GND - 180,000 uf cap 1st wire GND - 180,000 uf cap 2nd wire +8v - red wire +8v - other red wire Drive A is not getting 5V (it's 1.3-2v) Board is not sending the 5V to drive A Had to determine whether 5v may also not be getting the controller cards - therefore the board is not bad, nor are the CPU cards. Red wire coming from mother board +5v with P8 connector. Need to replace the 7805 inside heatsink, 6030B, the front-most 7805. Reply |
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