I FOUND THE PROBLEM!
the top left side screw got magnetized FOR SOME REASON and by removing the screw everything works perfect getting the screw near the hole drives the compass back to not working now i just want new side screws

gvm87 wrote:

I FOUND THE PROBLEM!
the top left side screw got magnetized FOR SOME REASON and by removing the screw everything works perfect getting the screw near the hole drives the compass back to not working now i just want new side screws

Yes, you are right.
The screws are magnetical and thats the problem with gyroscope.
If you are look on the screws, it's the top right screw.
If the screw fails, the gyroscope works much better.

Thanks.

Don Harry wrote:

http://www.ebay.de/itm/Screwdriver-Tips-Screw-Bits-Magnetizer-Demagnetizer-Screwdriver-Pickup-Tool-DE-/132025830599?var=&hash=item1ebd5a4cc7:m:m5hnfn0gIqQaQhP5wjXLShghttp://www.ebay.de/itm/Screwdriver-Tips-Screw-Bits-Magnetizer-Demagnetizer-Screwdriver-Pickup-Tool-DE-/132025830599?var=&hash=item1ebd5a4cc7:m:m5hnfn0gIqQaQhP5wjXLShg

thanks.....

but the question remains how and why did they got magnetized

Did you checked gyroscope reading alone or watching the compass application?

I think that the steel ferromagnetic screw just concentrates magnetic field coming from conductors feeding the processor (or other energy consuming component). Details here: http://bbs.blackview.hk/viewtopic.php?f=142&t=113590&start=10#p292156

Tomator wrote:

Did you checked gyroscope reading alone or watching the compass application?

I think that the steel ferromagnetic screw just concentrates magnetic field coming from conductors feeding the processor (or other energy consuming component). Details here: http://bbs.blackview.hk/viewtopic.php?f=142&t=113590&start=10#p292156

readings are stable and apps work normal
before finding the issue the compass was unable to be calibrated at all and was stuck to the west and apps like google earth was giving only position and no direction with street view option being used only manually and not with direction movement... even after hard reset and new rom
after the removal of all screws everything everything returned to normal after putting them back the problem returned even by just holding the screw near the hole the compass changes direction i now have put there temporary another screw as i haven't found a right size the one i use now is too short)
the gyroscope return to normal the compass still gives a low accuracy (i suspect there is another "evil" screw but i will deal with if after finding new screws and/or a demagnetizer as it don't interfere that much and only gives low reading seconds after calibration)) but do get calibrated (the calibration used to be unable no mater how long i moved the phone in an 8 like shape)

- black view should give with the phone extra side screws instead only the back ones

Hi,

For me this didn't work. I removed all screws and didn't see the difference. Here is what the compass showed while top edge of the phone pointed north:



Google maps as well as the compass application complained about low accuracy. But calibration is erratic:





Finally I put screws back.

Here are magnetometer readouts without, while winding the screw (large drop on X axis caused ba the screwdriver), and after I took the screwdriver away. Disturbances on the Z axis are maybe slightly larger with the screw but the difference is not significant:



And there is nothing about the gyroscope. The gyroscope is electromechanical (MEMS) sensor, not sensitive to weak magnetic fields. It looses calibration over time (I have once calibrated the zero point to +/- 0.003 and found today drift of -0.03) but low drift may be tolerated by the compass application.

Above are raw readings from magnetic sensor. There is also geomagnetic sensor that serves trigonometric function based on these values.



I'ts readings are also a bit unstable. This confuses compass and maps.

what can i say for me it worked having changed all the side screws everything works fine
maybe in your case there is a problem with the back screws
try removing all screws and the side steel thing and start adding them all back one by one to check what is causing the problem
also use a screwdriver with no magnetism for that


in my case with the old screws there was no cone on the dot at google maps there were just a dot like on a phone with no gyro at all
and the compass stuck here



the screw that caused the most problem was that one


after removing it everything were restored
the rest were causing only minor interference causing low accuracy

after changing all side screws and the problem disapeared and
restored the gyroscope and the compass both to full function

and putting it back disables they gyro and the compass stuck to the west north/west

I can confirm only that this is the screw is close to the magnetometer. My compass is not stuck at one position but moves quite freely pointing North from northeast to west. As you can see on screenshots there dynamic are drops on readings that cannot come from statically magnetized screw (especially when all screws were removed).

Apparently you had no problem with the gyroscope but with the screw near the magnetometer.

In my case there is no problem with the screw and I had calibrated the gyroscope but the magnetometer us useless. May it be due to a failure? Admin, what do you think?

I had a problem with the compass: got the error message "accuracy low, please recalibrate". I'd recalibrate, and the message "calibration successful" would immediately (within a second or so) be followed by "accuracy low, please recalibrate". I found this thread... maybe something magnetic near the sensor was disturbing the reading?

I took a compass, the real kind with a needle, and moved it around the phone. There was one screw which attracted one end of the compass and repelled the other. I removed the screw, demagnetized it, replaced it, and the compass now calibrates and keeps its calibration.

This screw was not where the one in the photo above shows it, but one holding the back on. Beware that many small screwdrivers are magnetized to help hold the screw in place during installation: using these will re-magnetize the screw.