The Denon DN-T620 is a professional CD and cassette machine manufactured from the late 1990s to early 2000s. The one you see here has a build date of 1999. As a professional model it came with rack brackets standard. The power cord itself is a give-away as to its intent. It is a heavy duty cord that looks like it could power an industrial lawn mower.
A couple of posts back I mentioned that my DB-T620 turned out to be faulty, which was a surprise as I originally thought it was perfectly fine. Now there’s a surprise for you!
In fact, the machine was causing CDs to skip very badly. Diagnostics on CD players can be problematic, and this was no exception. My best guess, well, it has to be the laser, right?
One we get the cover off of the Denon DN-T620 we see two important points:
- It is quite complicated because it has both a CD player and a cassette player/recorder.
- It is nicely engineered to be modular.
That last point is interesting in that it confirms this machine was pro-level and intended to be relatively easy to service, if necessary.
In the photo to the right we see the CD mechanism as the big plastic block of parts in the lower left corner. The green item in the top left is the power transformer. Two fuses are hidden from view, but are there, too.
The cassette component is mounted in the lower right, but is difficult to make out.
Here we see the cassette mechanism mounted to the back of the front panel. Looking closely we can see the drive belts, motor, and other parts of the player/recorder.
If we compare this to consumer-grade cassette tape machines it looks like this one is quite a bit more heavy-duty.
The fact is, this tape machine works great!
In my experience, working on a CD drive mechanism for a consumer-grade machine requires extensive dismantling of the unit. In the case of the Denon DN-T620 the CD drive is removable without further dismantling and include both the drive and the drawer.
Removing four screws and disconnecting three cable sets allows you to lift the CD drive out of the DN-T620. You can see it on the right.
When we flip the drive over we see the guts of the mechanism. The black plastic is the framework that holds the whole assembly and the drawer. The gray meta is the CD laser and player, and the green circuit board is associated with that part.
The two white plastic sockets with the wires coming out in the center of the photo are mounted on a tiny circuit board which is part of the laser optical pickup unit, OPU.
The next thing to do is get in there are check out the OPU. That is mighty delicate work.
NOTE: This post is for entertainment purposes here and to tell a story. Do not under any circumstances try working equipment unless you really know what your are doing. One tiny mistake and you can junkify your gear and maybe even give yourself a nasty, or worse, shock.