No, but do the red leds still work? The contacts may be dirty. Before I dared to open it up, first I'd try plastic compatible spray contact cleaner by CRC. Home Depot carries it in the electrical dept. It's $10 for a large can. I use UT on locomotive wheel and car wheel lightning contacts. I'd spray it sparingly under the stop bar, and in between the edges. Give a minute to dry out before booting it up.
Personally, if it operates fine otherwise, and you can live with it, I wouldn't send it for repair. If you really want it repaired, I'd call Marklin USA in Mo. And ask if they do repairs or can recommend a n authorized who does.

Hi Phil
I cannot say for the CS3 but for the CS2 (same casing with telescopic feet) the unit opens by removing all Torx screws including the one under the warranty seal
Then it looks like this (This is a CS2 NOT a CS3)



Here is the other side of the plastic case with the touching nose circled in red (in contact with the micro switch)


On the other side of the main PCB, there is a tiny SMD switch (apparently of mediocre quality as I had also problems with my CS2).
These mostly disappeared after multiple operation of the stop bar.
I do not recommend to inject loads of contact fluid into the unit as some high impedance circuits may be ruined by it.
Cheers
Jean

Yes indeed the CS3 has Torx screws but I don't want to open mine (works good and still under warranty).
But when you put the 2 units side by side you realize all they did is to change the motherboard and a better - same size - screen.
Cheers
Jean

OK, I opened up my CS3 to check out the STOP bar. A couple of notes anyone doing this should keep in mind. The body shells don't easily separate at the back. Persistence and very gentle persuasion will eventually get it apart. Same goes for getting it back together again. If you fiddle with it enough it will finally mesh and you'll know when it does. Don't force the shell halves back together.

First thing to disconnect is a battery that is housed in the bottom shell half. This is a common two pole polarized connector on the motherboard. Disconnecting this allows the two shell halves to be completely separated. The motherboard is attached to the upper shell half with two additional torx screws.

There are two ribbon cables between the display/touchscreen and motherboard. They are not very long BE CAREFUL! These, along with the cables connecting the two control potentiometers to the mother board use connector devices I've never seen before. The ribbons have bare conductors on one side. The cables slide into clamping devices mounted on the motherboard. I broke a leg off one of the clamp retainers for the potentiometer ribbon cables before realizing how they worked ! What I thought (and appears from above) to be a plug is actually a captured, tapered wedge that forces the ribbon cable's bare conductors against their respective contacts on the motherboard. The wedge slides out about a mm or two while remaining attached to the board mounted connector. The ribbon cable can then be slid out of the connector. Luckily, the wedge piece could still be used. The two potentiometer ribbon cables must be disconnected to get at the STOP bar. I did not need to disconnect the display cables. And, looking at the number, size, and spacing of the conductors on these cables, did not want to take a chance disconnecting them! Just be careful not to stress them.

In the end I was not able to discern what was malfunctioning with the STOP bar. I was able to completely remove it and the clear plastic piece KiwiAlan talked of in Post#3 for inspection. I could not see anything noticeably amiss or broken on either. The surface mounted microswitch on the motherboard mechanically works fine with a noticeable "click" so I don't think that is the problem.

I reassembled the CS3, and plugged in the power. The red LEDs lit up but the screen never came alive! Extremely concerned that I had just created a very expensive and not very effective boat anchor I carefully opened the CS3 again. After checking connections a second time, I closed it up once more. This time I put the xD memory card I had been using back in before I powered it up. It came alive! Don't think or know that the xD card made a difference but I'm not about to find out! Think I'll live with the non-functional STOP bar for the time being.

Hi Phil
This is great for you.
Have you made pictures you may share with us. I may help quite a number of persons here.
Cheers
Jean

Hi Phil, I have taken a few apart to fix this problem. I do have to admit I don't know where the problem is exactly because one can't see the alignment of the parts because the shells have to be closed.

Be persistent, it will click back in place and work and sound like it did before it was broken. I had to take one apart a couple of times to get it to work.

After it is working the next hard step is getting it back together. That was always harder for me than the stop button alignment!

Rick

After reading above post's, I will mainly use the mouse to start/stop my CS3. Tapping lightly to initiate shutdown.
I would have rather Marklin made the stop bar of neoprene or a rubber, at least an overlay in the center. Also two or three red leds would suffice. It is good that it is wide though. If you need to panic stop because of a short, it's easy to touch.