[Solved] Faulty touch screen in the car - radio, air conditioning and navigation control

Denso radio with 7-inch touch screen - radio, navi, air conditioning, etc. in a Ford Mondeo car.
The "touch" in this display has stopped working - it does not respond to touching anywhere. The screen itself lights up and displays everything properly as before, but I can not change anything by touching the displayed virtual buttons, such as radio stations, menus, etc.
All manual buttons around the blower radio are normal.
This probably happened while cleaning in the car when I used cockpit cleaning spray. I didn't realize it right away, because everything was displayed normally and the radio was playing all the time on the preset wave.
It looked as if something just hung up for a while, but just turning the radio on and off didn't change anything. So I decided to disconnect the clamp in the car to completely reset the radio and its settings. This, unfortunately, also did not help, except that now the radio asks for a PIN code (Standard behavior after every power disconnection). There would be no problem with it, because I have the original code, but unfortunately I am not able to enter it because the touch panel still does not work after the reset!
It looks like something has broken. Perhaps it is the touch panel itself or the electronics controlling it?
I disassembled the device, took out the display, which visually shows nothing bad, and corrected all terminals of the digitizer tape connections.
That's all I could do, but it didn't work - the touch still doesn't work.
This display is a Toshiba TFD70W24. Costs over 100 bucks with shipment via Alieexpress from China and waiting several weeks. And here I have some concerns. If only I was quite sure it was a display. Or maybe it's not his fault, but electronics and money I will throw down the drain and the equipment will still not work?
The main question for me is whether it is possible to have such a malfunction of the display that it shows everything nicely and only the touch does not work?
It seems to me that if there was some stratification of the digitizer, it would rather be dark or display badly or maybe I'm wrong and it is possible?
The entire used Denso set on the Allegro costs about PLN 900, which is quite a lot.
How do you think to change the display blind or not? Any chance this will work?

Display is display and touch is touch. You have a touch overlay on the display, so it's no wonder that the display works normally.
Check if you did not flood the tape with the touch (or something) - maybe it made a short circuit.

You have to disassemble this display more, you need to get to the connector / strip from the touch and wash it, if that does not help, the replacement.

jar59 wrote:

Is it possible at all to have such a malfunction of the display that it shows everything nicely and only the touch does not work?

Yes.

jar59 wrote:

It seems to me that if there was some stratification of the digitizer, it would rather be dark or display badly or maybe I'm wrong and it is possible?

Yes you are wrong, damage has no effect on the displayed image.

[td:e62fd6be0a] [/td:e62fd6be0a] Thanks to everyone for the hints. It made it very clear. So touch is a separate matter and it really is! I took the display apart as much as possible. The tactile overlay is glued to the outside of the display (photo 7) and has four tracks on the tape, which in turn is not directly attached to the display electronics (photo 4) but to the board on the frame with manual buttons (photo 9 - brown tape )
The touch panel tape on one side is directly soldered to the digitizer from the inside and there is no access to clean this connector (photo 8). It does not look very interesting on a close-up (photo 8) and it is difficult to visually determine whether there is damage or interruption to the touch path. All I could do was measure some resistance between these paths at the other tape connector. I did not know what to expect but it turned out that such resistance, however, occurs in different values between all four paths (the range is from less than 1k to 10.5 kilo)
So it would seem that since there is no break, the touch itself can be good? Perhaps, however, such a measurement still does not decide about its efficiency?
So the question is - Is it possible to somehow check such a touch to make sure if it is guilty?
Greetings, Jar.

Is this tape in photo No. 8 tightly stuck to the display? or is there a crevice that this cleaner could have gotten there.

Hello
I also managed to separate the touch panel from the display, as it turned out that they are separate, removable elements (Photo 33). Now it is better to reach the digitizer strip connector. You can see this place on photo 35 now. The gap between the tape and the plastic is very small and shallow. I tried very delicately to put the razor in there, but it went maybe 2mm deep and that's it. Of course, chemistry has a chance to get there, although I'm not entirely sure to what extent it is possible in conditions when everything is built-up?
However, it is interesting that after this treatment with a razor blade, the resistance measurement between the first and third tape paths changed. Before it was around 10.5k and now it's over 20k. Something must have happened there, but after reassembling everything it is as it was, i.e. the touch still does not work.
I think I have already reached the wall, because I can't see anything else that I could do without the total destruction of the touch panel. More and more I wonder if the assembly of a new touch (if I had!) Would change anything here. Maybe it was something bad that happened on this PCB where the touch tape is attached or even further in electronics?
I am also thinking about the possibility of attaching any other touch to see if there would be any reaction on the display. It is possible?

Hello again after over a month. The problem has been solved, so I will write what happened in the topic.
Well, I finally managed to find a digitizer without a display on AliExpress for 25 euro + shipping. In total, less than PLN 140. It was not identical to mine and in the listing description it was called: Modified 7 inch 4 pin Black Glass Panel Digitizer Touch Panel Lens for TFD70W24 TFD70W23 LCD.
The main difference is the tape connecting the digitizer with the electronics. Photo 37 shows both touch panels. On the left, the original, on the right, a new one - modified. In this new tape, the tape is much thinner, led out in a different place and is not properly shaped, which makes assembly difficult. The tape comes out in such a place (photo 40) that it overlaps another tape and it is quite difficult to fit. In addition, the tape must somehow be bent to bring it to the correct clamping clamp, which is not easy considering the limitation caused by the short length of the tape. In the end, I managed to achieve this by using additional fastening points, securing the tape against self-sliding out of the electronics clamp (photo 41).
After screwing the whole thing together and connecting it in the car, it turned out that everything works as it should and the touch panel responds correctly to touch.
And something else that may come in handy. In photo 42 I marked the resistance measured between individual tracks of the new digitizer. It is diametrically different from that in the damaged one, where the measured resistance occurs between absolutely all paths and not only those in photo 42.
Interesting facts: In photo 37 on the new panel (on the right) you can see joining the tapes - a kind of black, siliconized bun. It turned out that this join is not one-to-one, that is, for example, the right path before the join also corresponds to the right one after the join. This order is mixed up and perhaps this is also the reason for modifying this digitizer and adapting it to a given display model.
It is important that everything works in the end!
Thanks again to everyone who has spoken on this topic and put me on the right track!
Pos. Jar.