Wednesday, September 21, 2016

How to make PDF's searchable, for free!

If you have a scanned document and you want or need to make it searchable, there is a free software called PDF-XChange editor that will use OCR to overlay searchable text on the pdf. Quite handy really.

Saturday, September 17, 2016

Eppendorf 5415D Error 17 repair

The Eppendorf 5415D is a nice little desktop centrifuge, however, there aren't many online resources describing its failure modes. The instruction manual only says that error 17 is electronics related so you were out of luck until you found this site! So, here is how to fix Err 17.
The Eppendorf 5415 D

On to the repair!

What I found when messing with the centrifuge was that it would power on normally when it had been plugged in for a few moments and the power was cycled. This often indicates bad capacitors which are exactly the problem in the case of error 17. 
The offending capacitors are in the middle of the board


First, remove the drum and the casing. Then, you need to remove the pcb from the bottom plate. Don't remove the four screws holding the motor control module just yet, you'll be removing then when you've desoldered the jumper pins in the following image. 
Annoying jumper pins
The best way to desolder these I found is to remove the majority of the solder using a sucker. Then, use a small hook to lift the pins while heating the pad.
After that, you simply replace the capacitors near the 7805 voltage regulator. Their values are 220µF/25V and 22µF/25V. I didn't have the exact values on hand so I used 470µF/25V and 22µF/50V which worked fine. 
Good luck!



Tuesday, September 13, 2016

How to fix laptop keys

Sometimes the buttons on laptop keyboards will become responsive and require pressing straight on or very hard to register a click.
In some cases, it's enough to put a small piece of paper under the button in order to remedy the problem. Follow these easy steps to do it yourself and save you in upwards of $40.

Step 1: Remove the key

In order to remove the key, you need to lift the front of it with a tool. When nothing that won't scratch the keyboard is handy, I find it easy to use my fingernails.
You might need to use some force but it should come loose. 

Step 2: Cut paper into squares
 



Ideally, you want to use paper with adhesive backing like post-it notes or flag (or knock-offs). That's not to say that you couldn't use whatever shim you have handy but it's easier to do if the pieces of paper are stuck to the key.

Step 3: placing paper squares on the underside of button

place the squares you just cut up on the underside of the key. You might need to experiment with the size and thickness of the stack of squares. Too many and the key will become too sensitive, too few and it might not work. 

Step 4: replace key

In order to replace the key, you need to first push it down at the back like so:

Then, you simply push it down and it should seat properly. It might take you a few tries to get it right the first time. 



Thursday, September 8, 2016

How to remove the earpads on bluedio headphones

Sadly I do not know where to find replacements. If you know how please contact me.

How to fix google chrome's pdf viewer

Chrome's pdf viewer. 
After installing an old version of foxit reader the native PDF viewer in chrome stopped working. In order to make it functional again.
  1. Go to chrome://plugins/
  2. disable chrome pdf reader and restart. 
  3. enable chrome pdf reader and restart again. 
After going through those steps it should work as normal.