Friday, May 19, 2017

Repairing an ipad air 2 with spots on the left side of the display

Well after swapping the old battery in my ipad air 2 I got a nasty surprise....
Spotlights on the left side of the screen!
First thought was: I messed up the screen with my smd airstation heat while trying to remove the glued display :-(
So I ordered a new one, installed it and ..... still the same problem.

After some googling and some more you-tubing. I spotted the same problems with the Iphone 6 and 6S. Apparently it is the backlight filter fuse that fails.

One small problem, really small, even so small that I can't see it without a microscope?

The 1 euro cent coin has a diameter of 16.25mm

the top left and middle components are the failed filters, notice the fine split in the middle one

Next steps in the coming days will be to order the components and try to desolder the filters without killing the ipad air. I don't have any nano tweezers so it will be challenging...

Heat issues

Filter was replaced, both of them to be sure. But spots still are there. A new issue has occurred, the ipad heats up :-)

The cause is the failing zener diode. A diode test reveals 0.2v on the left (good) one and 1.5v (bad) on the other. So I replaced it and all works now.

The cause of all this was me forgetting to FIRST remove the battery connector before disconnecting  the display flex cable. It shorted the fuse and the zener diode.

Tuesday, May 2, 2017

Carette 300 bar 4500 psi compressor review test - Part2

This is a part2 of the review, goto part1

Adding a PMV to the standard Carette

You can find priority valves or PMV on the internet for less than 100$.
Some Bauer compressors use an OEM PMV which can be found in the US as model 211 priority valve. Just google it. I wasn't able to find it here in Europe.

Some sites where they sell it :

A good article on using a PMV in a compressor can be found at

So where do you put in on the Carette compressor? Ideally it should be put after the last filter but it is easier to put just behind the Oil water separator. Since almost all of the water is removed by the Oil water separator with the PMV set at 2000psi, that's just fine.

On the European model (the one I have) the fitting from the Oil-water separator to the filling hose is 1/4 BSPT.
The PMV has a 1/4 NPT fitting.
So you need:

  • a 1/4 female barrel BSP (to connect to the BSPT)
  • a 1/4 male BSP to male NPT (to connect to the PMV input)
  • a 1/4 male NPT plug or 1/4 NPT gauge (to connect to the PMV output1)
  • a 1/4 male NPT to male BSP (to connect from the PMV output2 to the bleed)
  • a 1/4 female BSP BLEED (to release pressure between the PMV and the tank you are filling)
  • a 1/4 male BSP to BSPT (to connect to the standard filling hose which is female BSPT)
  • 4 bonded seal washers
All these fittings can be found here in Europe on but should not be difficult to find elsewhere.
FYI the connections on the standard carette filter are metric m10x1.

The end result:
Priority valve fitted to the exit of the oil water separator