N810 Touchscreen stop working? One solution inside
 

It is a glorious day!!!!!!

My wonderful N810 touchscreen stopped working. I took it apart and cleaned out the screen and checked all connectors to no avail.

I took a chance and ordered a Main Internal Flex Cable Assembly from CellularDr and revived my N810 today. The part number is 0269975 and that is the Nokia N810 Main Internal Flex Cable Assembly with Connectors.

The replacement is not for the faint of heart, there are some tight areas to get into. You need a Torx T4 screwdriver and a small flat prying device. I followed the instructions in a file called Nokia N810 Tablet Wimax Disassembly.pdf

Woo hoo!!!! Hope this helps any other N810 owners.

Frank

Re: N810 Touchscreen stop working? One solution inside
 

Hi Frank. My N810's touchscreen functionality has just died and I'm - rather nervously - thinking of trying the same surgery as you did back in January.

Looking at the disassembly instructions, they say of several sets of screws "Discard these screws. Do not use them again."

Should this warning be taken seriously? If so, can you suggest a source of replacement screws? Or are these standard items?

Re: N810 Touchscreen stop working? One solution inside
 

I'm sorry I'm a bit late on the reply, I didn't see the post.

I did not discard the screws nor do I think it's required.

Frank

Re: N810 Touchscreen stop working? One solution inside
 

The disassembly instructions are for a technician doing repairs in a shop. They would have the replacement screws and the torque wrench to put the exact tightening on the screws. For you, reuse the screws.

Re: N810 Touchscreen stop working? One solution inside
 

Ugh, looks like the main connector is cracked and has some bent pins on mine... Does anyone know where to get one of these replacement parts (ie. the main internal flex cable)? Every place I find says they're out of stock... :(

Re: N810 Touchscreen stop working? One solution inside
 

http://www.sparepart.dk/product.asp?product=12844 ?

Re: N810 Touchscreen stop working? One solution inside
 

Hi Frank,

I have similar or same problem as you did. My touchscreen works is work properly sometimes (5% of time), has vertical and horizontal displacement (70% of time) and does not work at all (25% of time).

Calibration did not solve the issue.

The device switches between states randomly on keyboard slide in/out.

I've examined the flex (disconnected and connected both connectors board-flex and flex- touchscreen), cleaned the touchscreen (once it was removed from the flex).

I've noticed there is another thin flex on the sliding mechanism, which is in bad condition (the layers on this flex are separated). It seems its only purpose is to make galvanic connection (looks like RF interference precaution) between sliding part and the metal support, but I am not 100% sure.

Do you know the purpose of this thin flex?

Did you have mixed behavior as described above?

Re: N810 Touchscreen stop working? One solution inside
 

Actually the only place I could get a spare main cable was on eBay on the inside of someone else's bricked N810. Scary tablet microsurgery ensued, but now my tablet is working again... :D

Re: N810 Touchscreen stop working? One solution inside
 

Hi, I was wondering if you had same symptoms as describe avove?

Do you know the purpose of this thin flex connecting moving part to the base of sliding mechanism?

Re: N810 Touchscreen stop working? One solution inside
 

Looks like sparepart.dk's website restructure broke my previous link, but it looks like they still have the main cable in stock.

Note: I have successfully bought parts from these people, but have no other affiliation.

Re: N810 Touchscreen stop working? One solution inside
 

What about your symptoms?
Do you know to furpose of tiny flex between sliding part and base?

Re: N810 Touchscreen stop working? One solution inside
 

Your device operation and mine appear to be identical. Opening and closing the keyboard could cause it to change behavior state.

I don't know the purpose of the thin flex. It might be described in the disassembly manuals, do you have access to those? If not, you might try googling them, I no longer have them.

Frank

Re: N810 Touchscreen stop working? One solution inside
 

Thank you Frank, I will post the result once I try repair.

Re: N810 Touchscreen stop working? One solution inside
 

The flex ribbon on the slider grounds between the two halves. If it brakes you will not have a working screen as I can attest to.

Re: N810 Touchscreen stop working? One solution inside
 

Can you be more specific.
Is this related only to:
- touch
- display itself
- both touch/display (camera and light sensor might be affected too)?

Re: N810 Touchscreen stop working? One solution inside
 

Nope, mine was a chipped connector on the main bus cable... screen went black, corner light faded green to off, then nothing... no idea what the thin flex does... I'd have to open the unit again to make a guess based on what it was attached to...

Re: N810 Touchscreen stop working? One solution inside
 

Yeah, I think I remember trying these guys only to find out, upon calling them, that their site was just out of date and they didn't actually have any more in stock, and Nokia won't make any more... Trying to get people to buy the N900 I would guess... :( Can't hurt to ask tho as I could be mistaken.

Re: N810 Touchscreen stop working? One solution inside
 

I've ordered the Main Flex from sparepart.dk together with SS-93 tool.

Hope to receive it by the end of month. Given the events related to N9 and N950, it would be a good idea to buy additional battery as well.

Re: N810 Touchscreen stop working? One solution inside
 

Do you have the PDF document for how to disassemble the N810? I found it most helpful...

Re: N810 Touchscreen stop working? One solution inside
 

Yes, I've found it, also there is another source of more detailed images:
http://people.openmoko.org/joerg/N810-disassembly/

The tiny flex I've mentioned earlier is here:
http://people.openmoko.org/joerg/N81...00265_jpg.jpeg

Above the left lower torex base.

Re: N810 Touchscreen stop working? One solution inside
 

I've just replaced the main flex with the spare part received from sparepart.dk. They are very professional, I've got my flex very neatly packed.

After replacing the flex, it still behaves the same.

So either it is the tiny flex on the slide mechanism or the touch screen or the main circuit.

Once I manage to make the screen fully operational, if I move a slider very gently (e.g to close it, while taking care not to disturb the touch screen), it switches to the offset mod. It looks like there is some interference that disturbs the touch readings from that point. The base of the sliding mechanism is grounded to the main board with two separate extensions (pins).

The sliding part itself should be grounded with the tiny flex. I've just confirmed that tiny flex does not ground two parts of the sliding mechanism any more.

There is a tiny magnet attached to the properly grounded part, which makes me wonder if the tiny flex is used to prevent interference, and/or more accurate resistance readings.

Any idea on how to ground both parts of sliding mechanism properly?

So far I am thinking about using torex bases to bring additional GND to the static part of sliding mechanism through torex itself.

The tiny flex seems to be glued on both ends. Any idea where can I find such replacement?

Re: N810 Touchscreen stop working? One solution inside
 

After checking the connectivity of the tiny flex and inserting tiny piece of aluminium foil to connect both sides of slider mechanism, the behaviour remind the same.

With flex that was recently replaced there are only two options:

• touchscreen
• main board connector, or part of main board

I've decided gamble and replace the following parts:

1. slider mechanism
2. main flex (since it is glued to slide mechanism)
3. touchscreen

Ordered parts from http://sparepart.dk

Re: N810 Touchscreen stop working? One solution inside
 

I've just received the replacement touch screen, replaced the old one, and my N810 is finally in working condition!!!