Koss KS2503 "MSG 04" problem

I had this MSG 04 problem. Opened the player up. Messed around. Figured out that the 5-disc tray was hanging up a little during the initialization.

The issue is that the tray screws into and rotates around a stand-up beam. On the underside of the tray are gear teeth which are spun by a gear on the main unit underneath. The real culprit is the stand-up beam in the very middle. It is too long.

The fix is to first try just tightening the middle black screw holding the tray onto the stand-up beam. If this tightens and MSG 04 goes away, you're done. If it does not tighten at all or much at all, then remove the screw (actually a bolt) and using a razor or sharp blade, scrape the top 1/4 millimeter off the stand-up beam. Apply some grease around the beam and on top.

Note, you may have to remove the tray to do all this. If so, that is the most tricky part. Carefully lift on the tray on the front side as you rotate it. Try to free a disc circle edge over the top of the front DVD cover and free the tray. To re-set the tray, put it on the stand up beam with the front side of the tray slanted up and slowly rotate while setting it in and down.

After re-seating the tray, screw the bolt down but do not tighten all the way. Tighten it enough to allow rotation and enough to rid the msg 04 problem.

I shaved my stand-up beam and have never seen a MSG 04 since.

Main support number 1-800-USA-KOSS
Email customer support support@koss.com

The error message of "04" is the disk tray timing.
It occurs if the tray spins too fast or too slow
to be registered by the timing window. The system cpu was designed to see certain pulses register at a specific time through the notch windows you will see under the main tray carraige. Shaving the main center post in fact may fix this, since it will allow more tension on the center post, and slow the timing wheel pulses down for a good pickup. This is just to sensitive of a timing window for the tray, and is due to poor design on the mother board. Also, to all thse who have gone out and bought the upgrade firmware to remove the DVD region block on this model. This was a waste of money. Since the region unblock is easily done through the remote control by entering "16719" on the remote, and then selecting "0" for all regions.

Don't know what "techman" was thinking, I'm having the same problem with my KS2503, first off that thing isn't going to be on Koss.com, its made by Koss electronics (Kosselectronics.com) but hey it isn't on that site either, basically the thing is junk and Koss has no way of fixing the problem, sorry, but i'm just as screwed as you are.

never heard of this before but Im betting its an eror code so contact the manufacturer at www.koss.com

I am trying to find a replacement remote for the system.

We just had this same problem so we just flipped the machine over and opened up the tray that way. All the DVD's came out and now it works good. Very strange