Display dead after replacing touch screen

[clivech]

I bought an after-market touch screen on Ali Express and fitted it, following instructions on YouTube. I removed the whole display/navigation unit from the car to make access easier. Everything appeared to go well. The screen went back up to its vertical position when I plugged one of the cables back in on the back of the unit. But when I turned the car on, the screen remained black. The tilt button doesn't work either, so I can't take the screen off again. I checked all the fuses in the 3 fuse boxes inside the engine compartment and they are all good. All the plugs went back into the back of the unit ok, although I broke one of the plastic locks that holds one of them in - but it still seems to fit in properly. What can I do? I really want to get the screen to tilt again so that I can get at the touch screen and make sure all the ribbon connectors are properly connected etc. But how can I get the screen to tilt if the button isn't working? Thanks for your help.

 

[clivech]

Quick update: I managed to very gently pry open the screen from the unit with a screwdriver. That gave me access to the ribbon connection on the back. I took off the plate that covers it, unclipped it and did the reverse. The unit came to life, including the tilt button. Phew. But the screen doesn't work properly. Nothing happens, for instance, when I touch charging timer. But something I haven't touched comes up, so I think the connections to the screen on the ribbon cable are probably different. I'll take a look at the long thread on replacing the touch screen, but I think I may have to move the connections around.

 

[GentleGiant]

It doesnt help you now, but NEXT TIME, always test before inserting into car; and with something like this, buy cable extenders, so you can test EVERY function, before committing to fitting it.

I have always been very leery of replacement/upgrade infotainment systems from 3rd parties; my only experience of them was years ago, but I lost a LOT of functionality, going from the OEM unit to even a branded replacement (Clarion).

 

[Dooglas]

"I bought an after-market <bleep> on Ali Express and fitted it, following instructions on YouTube."

What could possibly go wrong?

 

[jkline]

Aftermarket sheet on cars can produce no end of mischief, especially parasitic draws.

 

[clivech]

Looks like it's one of those units with the wiring in the wrong order for the Leaf. I've found others that are supposed to be wired correctly for £15. May spring for it, since I can always return it if it's no better. Meanwhile an engineer friend of mine is looking into the practicality of moving the wires in the ribbon connector to see if it works. Tricky bit of soldering required.

 

[GentleGiant]

Looks like it's one of those units with the wiring in the wrong order for the Leaf. I've found others that are supposed to be wired correctly for £15. May spring for it, since I can always return it if it's no better. Meanwhile an engineer friend of mine is looking into the practicality of moving the wires in the ribbon connector to see if it works. Tricky bit of soldering required.

I wouldn't TOUCH the wires in the ribbon cable, instead buy a new male and female cable connector and some ribbon cable, and make a cross over to go between the car and the head unit.
You wreck a connection in these spares and it isnt an expensive mistake, just buy another; wreck one in the car - and you are looking at a lot of time and money to fix it.

 

[vvitecd]

Quick update: I managed to very gently pry open the screen from the unit with a screwdriver. That gave me access to the ribbon connection on the back. I took off the plate that covers it, unclipped it and did the reverse. The unit came to life, including the tilt button. Phew. But the screen doesn't work properly. Nothing happens, for instance, when I touch charging timer. But something I haven't touched comes up, so I think the connections to the screen on the ribbon cable are probably different. I'll take a look at the long thread on replacing the touch screen, but I think I may have to move the connections around.

different touchscreen "pinout"

 

[clivech]

I wouldn't TOUCH the wires in the ribbon cable, instead buy a new male and female cable connector and some ribbon cable, and make a cross over to go between the car and the head unit.
You wreck a connection in these spares and it isnt an expensive mistake, just buy another; wreck one in the car - and you are looking at a lot of time and money to fix it.

Not sure I quite understand. When you say "make a cross over to go between the car and the head unit", where would this go, if not between the screen and the PCB? I am hoping the original supplier will send me the extender that should have been in the box and wasn't, but it would still require moving the wires in the ribbon cable around.

 

[vvitecd]

Is it equipped with an extender or "glass" is connected directly to the PCB?

 

[GentleGiant]

Not sure I quite understand. When you say "make a cross over to go between the car and the head unit", where would this go, if not between the screen and the PCB? I am hoping the original supplier will send me the extender that should have been in the box and wasn't, but it would still require moving the wires in the ribbon cable around.

Yes, it would go between the existing car wiring loom terminal and the head unit terminal - but you would avoid having to unsolder either the car or head unit looms and risk damaging them.

So if the car loom went 1,2,3,4,5, but the head unit needed 3,1,5,4,2, you would just wire the head unit end of the cable that way - "crossover" is the commonly used name for any cable that changes the pin layout between the two ends; it was quite common on early computer ribbon and serial port cables, even some early USB cables.

 

[vvitecd]

mainly you can check the resistance of the original and new glass to understand (probably) what is wrong

 

[clivech]

Yes, it would go between the existing car wiring loom terminal and the head unit terminal - but you would avoid having to unsolder either the car or head unit looms and risk damaging them.

So if the car loom went 1,2,3,4,5, but the head unit needed 3,1,5,4,2, you would just wire the head unit end of the cable that way - "crossover" is the commonly used name for any cable that changes the pin layout between the two ends; it was quite common on early computer ribbon and serial port cables, even some early USB cablesLuckily this is just the mribbon cable from the head unit to the screen. No need to touch the car loom. I'm now waiting for my new screen with "crossover" to arrive. I found one that seems to have the same configuration of wires that cross over in the ribbon cable as the one I took out (and then had to put back in!). I'll let you know if it works. Got a full refund on the other one, so not much lost, except time!

 

[clivech]

I finally bought another one on AliExpress and it fit perfectly and works without any adaptation:
https://www.aliexpress.com/item/100...der_detail.order_detail_item.3.7218f19cpETp2w