hi,I have a cld 2850 I have had for years,which I confess I have used much more for playing cd's than laserdiscs in recent years(although I still own my laserdisc collection),it went bang and upon removing the cover I traced the problem to the a blown fuse on the power supply board,I replaced the fuse,but it blows instantly on power up,I have tested all the diodes and resistors on the primary side of the power supply and they were fine,so I recapped the board,but it still blows the fuse as soon as it has power switched on,any ideas if a faulty power regulator would cause this or is it something else?,I have checked all the tracks for dry joints/shorts ect and there are none,Im a bit stumped what to check next

thanks in advance

Unplug all the outputs from the power supply board. Then jumper the +5 Ever output to the ON/OFF pin which turns on the remainder of the board and that will tell you if the issue is on the power board or another board. From you description I'm taking it for granted that you can plug in the board and the +5Ever output does have +5VDC on it and when you press the ON to take it out of standby the fuse blows.