Saturday, July 9, 2016

Estes ProtoX Quadcopter Motor Replacement

In my latest YouTube video I show how to replace a damaged motor in an Estes ProtoX quadcopter.  I received one as a gift, and bumped it into a wall when flying it and damaged one of the motors.  The local RC hobby shop had replacements, so I picked up a set and filmed a video on how to remove the bad motor and replace it.  Note that there are two kinds of motors, one rotates one way and the other rotates tbe other way.  The direction of rotation is indicated by the color of the wires attached to the motor.  One kind has white and black wires, the other has red and blue wires.  You must use one of the same color wires when doing the replacement or the motor will spin the wrong way.  Also, be sure to connect the wires with the proper polarity.  On the white/black motors the white wire should be connected to the point on the PCB with the "+."  On the red/blue motors, the red wire should be connected to the point marked with a "+."

Sunday, April 24, 2016

Battery Pack Failure Prevention

In my first YouTube video I showed the failure of a power tool battery pack that I had rebuilt with new cells I bought online.  The cells have great capacity and long life, but they have one problem.  The thin plastic heat shrink coating fails if the cells rub against each other, causing an internal short that causes the pack to overheat and fail.

In this video I show how I added paper separators between the cells to prevent the failures.  I cut paper strips and slid them in between the cells of the existing packs, in a winding pattern, to prevent shorts.  At the end I show how I wrapped every second cell with individual pieces of paper when I built a new battery pack.

Sunday, April 3, 2016

Craftsman Garage Door Opener Remote Repair

My Craftsman pocket size key chain garage door opener remote quit working.  In this video I take it apart, diagnose the problem, and repair the remote.  I also show how you can check if the remote is transmitting using a software defined radio dongle.

I found a bad solder joint, but the solder joint was not cracked, it looked more like the solder never properly flowed onto the part lead when it was soldered, so that was probably not the reason the remote quit working since it was likely manufactured that way and had been working for a couple years.  

Shortly after I bought it, the little plastic loop on the corner where you attach your key ring broke off, as I am sure happens to every single one of these things ever manufactured, so I replaced it with a small loop of large paper clip wire that I bent into a loop shape.  It turns out that one of the ends of the wire loop had been hitting the circuit board and wore through a trace.  I show how to repair the trace, resolder the bad joint, and fix the problem with the wire loop so it doesn't happen again.

Monday, March 28, 2016

Power Strip FAIL

About a week ago I posted a new video on my YouTube channel where I take apart a power strip that failed on me one day with a loud bang, to see what is inside and how it failed.

One day I was using my desktop computer when it shut down with a bang.  I thought the computer's power supply had failed, but it turned out that it was just the power strip.  The power switch was stuck half way between off and on.  I look at the construction inside, the poor build quality, and how some of the contacts in the outlets are bent back enough that I am surprised the cords plugged in were actually making contact, and I disassemble the failed switch.

Tuesday, January 26, 2016

Self Igniting Propane Torch Repair

Recently I decided to build a fire in my good old-fashioned wood fireplace, and like any well prepared Boy Scout, I planned to light it up the easy way, with my propane torch.  I screwed on the propane bottle and before I even had it tightened, I heard the sound of propane leaking.  My first thought was that the valve was not closed, but I tried to give it a quick clockwise turn and it did not move.  The valve was closed tight.  I realized the sound was actually coming from the inside of the torch handle, so I quickly removed the propane bottle.

When I disassembled the handle to diagnose the problem and make a repair, I also found that the wire clip that connects the ignitor button to the valve body clips on very loosely, and because of this, if the button were pressed, a spark could have occurred inside the handle where the propane was leaking, and the torch could possibly have exploded in my hand.  Any combustible gas has a certain ratio of air to gas to be able to ignite, and too far outside that range and the gas won't burn.  I don't know how wide that range is with propane, and therefore how likely ignition of the propane inside the handle would be, but the chances are greater than zero.

But, back on the failure.  I disassembled the torch and found the tube that connects the bottle fitting to the valve was no longer properly attached to the bottle fitting.   In the video I show this failure, provide a quick discussion on how the torch works, and I perform a repair and demonstrate that the torch is working again.

I do not know when this failure occurred.  The torch worked fine last time I used it.  Therefore, for safety reasons, I do not recommend leaving a propane bottle attached to a torch when it is not in use and being monitored by someone qualified to assure that it is working properly.  And do not press the ignitor button on a torch if you have any reason to believe it could be leaking propane or is not otherwise in perfect working order.

Monday, November 2, 2015

Toshiba Satellite L55t Laptop Hinge Repair

A couple months ago I shot some video of my method of repairing the broken hinges on my Toshiba L55t laptop computer and only recently got it edited and uploaded to YouTube.   At the time it was about 9 months old.  The hinges broke free from their mounting points inside the LCD panel.   When opening or closing the lid, the torque on the hinges would pop open the corners of the LCD panel.

Opening the panel, I found that the hinges were fastened to the plastic back shell of the LCD panel by several threaded brass inserts that were pressed into plastic rings, each ring having several tiny radial supports.  They broke completely free and when I opened the panel, the screw, nut, and surrounding plastic just fell out.  This is a faulty design that clearly is not strong enough to withstand even the force of normal usage.

I  repaired the hinges by totally disassembling the laptop and LCD panel, gluing the brass insert nuts back in position with superglue and then surrounding them with epoxy for support.  Last, I filled the whole area where the hinge attaches with additional epoxy before screwing the hinges back in place.

Part One of the video contains a discussion of the problem, and shows the disassembly of the laptop and my preparations for the repair.

Part Two shows the repair process and reassembly of the panel and laptop.

If you like the videos don't forget to subscribe to my YouTube channel and hit the old Thumbs Up under the video.

Monday, August 17, 2015

How to Void the Warranty on Your Laptop

Back in November 2014 I purchased a Toshiba Satellite L55t laptop computer.  I thought I got a great deal on it, and in the past Toshiba laptops have been very reliable at places I have worked.  But this proved not to be the case with this one.  So I had to tear it apart to fix the hinges, which broke completely free inside the LCD panel.    I shot a quick video just to show it in it's disassembled state.  A longer video will follow showing the problem and my attempt at fixing it.