QUOTE(Danny-boy @ Jan 12 2009, 06:48 PM)

Sorry to gatecrash this thread but is there a tut for replacing logic board?? Had a look and couldn't find any. And p.s. Can you replace an ver. board with any other ver. (Hitachi)
Follow the Laser replacement tutorial for the Hitachi, it shows how to remove the Logic board before the laser is replaced, so just go that far on each drive and then install the original Logic board in the new drive.
Any version Hitachi Logic board can be swapped into any version Hitachi chassis, they're all the same mechanically, the only difference is the v78/v79 boards are a tiny bit thicker, so it may not fit perfectly into a v59 or lower chassis, but it still fits and will work fine in them, they all have the same connections.
Another thing to look for with the Hitachi drive is the Spindle motor, it can get all gunked up and cause disc reading issues as it's not spinning the disc fast enough. This can be resolved by removing the motor and cleaning/relubricating it and needs to be done properly as the screws that hold it in place also adjust the tilt/angle of the disc and if those get all messed up it's not going to read the disc when the Spindle motor is reinstalled.