NeXTStation Turbo Color (ADB)

Disassembly Notes
Disassembling the NeXTStation is extremely simple, and is designed for servicing. To remove the motherboard only a total of 4 screws need to be removed.

First unplug the unit, removing any other cables or adapters connected to it.

Undo the single Phillips screw on the back. Then lift the top cover up and off.

Once inside, disconnect the SCSI ribbon cable and molex power for the hard drive from the motherboard.

Remove the single Philips screw holding the hard drive mount in place. Lift up from the screw side and the hard drive tray will rotate, hinging on the opposite side before lifting out.

Disconnect the floppy ribbon from the mainboard (there is no separate power connector, power is over this ribbon).

Remove the single Phillips screw holding the floppy drive in place, and lift and rotate it the same as the hard drive to remove.

Disconnect the 2 pin fan header, and the power supply connector. Both lift straight up, the PSU one may take some force. Remember to hold down the motherboard while doing so.

Finally remove the single Phillips screw holding down the motherboard, and lift from the front edge. The board will come right out, mind the connectors at the back.

Mainboard
PN-4244.00

Only the SMD caps seem to leak, the through-hole ones appeared just fine with no sign of leakage below them when removed. However they are very easy to desolder and there are only 3, so the cost of doing so is minimal.

While a multi-layer board, the through hole capacitors are very easy to desolder owing to large through holes. You are very unlikely to damage the board recapping with only basic tools.

NOTE: No components have reference designators and polarity is NOT marked for capacitors. Through hole capacitors should have their positive leg in the square pad hole. When viewed with the connectors at the back, all surface mount capacitors should have the negative stripe to the right, and the through hole ones to the left.

Mainboard
Replacement TH parts number is 35v instead of 25v, but works fine and is low ESR.

If parts are not available or different selection is preferred, you can use the values in the Original Parts section to perform a parametric search

Related Links

 * https://lowendmac.com/next/nscturbo.html