I was recently asked by a customer to repair and service his Marantz CD-63 KI Signature CD player. The player was misbehaving, not reading the table of contents (TOC) with some discs and was also skipping occasionally.

I was actually really pleased to work on one of these classic disc spinners again. The Marantz players were all very similar across the CD-63 – CD-67 range and the SE and KI Signature models really only brought parts quality improvements in key areas, rather than different circuit layout. This range of players is all very serviceable and upgradeable, using some quality replacement parts in critical areas.

Anyway, this player’s laser lens was dirty and the output power was down slightly on what it should be. This resulted in the initial focus not being achieved at every load, hence the failure to read the TOC with some discs. Standard practice here is to measure the laser’s output power and adjust if possible to bring the emission back into line. I also always lubricate the sled mechanism, loader, check rubber belts and replace where required and generally clean and tweak players when I have them on my bench.

Sometimes small adjustments to focus and servo tracking and gain will restore the player’s ability to read discs reliably. In the case of this Marantz CD-63, I tweaked the laser output power very slightly, cleaned the lens and lubricated the sled mechanism and she worked perfectly once again.

It is worth mentioning a couple of points about laser output. The power output or energy the laser diode emits will decrease linearly over time. This is normal and to be expected and the standard method for resolving this is to replace the laser assembly, a fairly straightforward process. Sometimes a small adjustment of laser power output can considerably extend the service life of the laser, but the laser’s output power must be measured, to ensure the diode does not overheat and burn out.

Dialling in too much power can cause the laser to die as soon as the power is turned on, so DO NOT ADJUST LASER POWER OUTPUT unless you know what you are doing and have a reliable way of measuring output power! In fact, these days I have an excellent supplier of replacement mechs for these players and I prefer to simply replace the laser with a brand new one, like this one: