Fixing an Emerson mini refrigerator

This post focuses on the repair of an Emerson mini refrigerator that was not cooling properly.  As you can see in the photo above this is one of the taller mini fridges.

As you can see from the label above it is an Emerson mini fridge with product code CR519B (a link to the product manual http://www.emersonradio.com/resources/owner_manuals/manual_1313100237.pdf).

Whenever I had tried plugging in the refrigerator there was an audible clicking noise as the compressor attempted to start.  The clicking would repeat itself about three times before it stopped.  A Google search on the symptoms suggested that the compressor start relay was burnt out.

The label for the compressor, which seems to be a fairly generic compressor and fortunately was not the cause of the problem.

The compressor start relay and overload protector are attached to side of the compressor and covered by a plastic cover held in place with a metal clip.  Removing the clip was fairly simple and just required a bit of leverage with a flat head screwdriver.

Removing the plastic cover revealed the overload protector and the PTC (positive temperature coefficient) start relay.  You can see them attached to the compressor pins in the photograph on the left.  They are separated from the compressor in the photo on the right, where the overload protector is the item attached to the beige clip on the bottom and the PTC relay is attached to the blue clip to the right. 

As I had removed the relay components from the compressor I took the opportunity to measure the resistance of the compressor windings.  Apparently the way these sorts of compressors work is that there are a two set of motor windings for starting and running the compressor (as starting the compressor from a standstill requires significantly more power that it takes to keep the motor running continuously).  The resistance between each of the compressor pins is noted in the diagram on the right.  As the resistance between the two bottom pins is roughly equal to the sum of the resistance between both pins and the top pin this shows that the compressor windings are neither short-circuited nor open.  This is fortunate as a faulty compressor tends to doom refrigerators to the junkyard (compressor repair is generally more expensive than buying a new fridge).

I then tested the overload protector and found continuity between the pin where it attaches to the beige clip and the socket for the top compressor pin (the pin socket is the metal bit in the center of the photo on the right).  This indicated that the protector was working properly (which was logical as the protector closes the compressor to try to start itself but opens the circuit when it heats up - which happens in the case of repeated failed starts).

That left the PTC relay as the likely source of the problem.  The PTC relay contains a thermistor that initially allows electrical current to flow across the start windings of the compressor.  As the thermistor heats up its resistance rises along with the temperature (hence positive temperature coefficient) until the current no longer flows through the start windings, flowing instead through the run windings (which is important as having current flow through the start windings for too long could possibly damage the compressor).

I used a multimeter to test the resistance between the two pin sockets of the PTC relay and read an astoundingly high value of more than 2000 ohms, proving that this was the faulty component.  Upon shaking the relay I heard a faint rattle (this is another one of the telltale symptoms of PTC relay failure as I had learned in my research on Google). Curious, I pried open the relay with a small flat head screwdriver and discovered the reason why.

The PTC thermistor inside the relay was cracked (with the loose pieces making the rattling noise) and seemed to be worn where the disc was held by the metal contacts.

Fortunately the PTC relay is very inexpensive to replace and I was able to order one from Amazon for $2.41 (including shipping) from China.  Had I been in a rush I could have ordered one sooner from a closer location for a significantly higher sum, but I had the liberty of time.  The replacement arrived in a few weeks and was near identical to the original (the two photos above of the new relay should demonstrate the similarity to the old one).  It was then just a simple matter of putting everything back together and testing the refrigerator to make sure that it worked.  All in all I think this is one of my favorite DIY repairs for its simplicity and the sheer cost-effectiveness of replacing the relay versus buying a new mini refrigerator (not to mention the simple environmentally-friendly pleasure of saving this appliance from the junkyard).

Fixing a Bissell vacuum brush roll

Now for something actually worth posting...

A little while ago I noticed my vacuum was making a high-pitched squealing noise when the carpet brush was rolling.
The vacuum is a Bissell Lift-Off Multicyclonic Pet Vacuum with model number 89Q9-4 (https://www.bissell.com/lift-off-multi-cyclonic-pet-vacuum-89q9).

The vacuum

After I removed the six screws on the bottom of the vacuum and took out the brush roll I saw that one side of the roller (part number 2032085) was melted and degraded.  Now the vacuum is well out-of-warranty so the standard options would be to either buy a new vacuum or purchase a replacement brush roll (about $27 plus shipping and tax at SearsPartsDirect:  http://www.searspartsdirect.com/bissell-vacuum-parts/2032085/0020/214/model-89Q9/0116/0645000.html).  I instead took a third option and decided to fix the brush roll (fortunately the damage was easily fixable).

Just remove the six screws marked in red.  After removing the plastic cover the brush roll is easily removed by pulling it from the slotted ends and slipping off its belt.

The melted and degraded end of the roller was the black end which has a rectangular protrusion to hold it in place.

The damage was more easily visible when the black cap was removed by prying it out with a flat-head screwdriver.

The damage to the blue cylinder portion of the roller was limited to just the outer edge (the metal axle can just slide out with a bit of force and the plastic bearing holders can be popped out from the blue cylinder).

This was in contrast to the non-damaged end of the brush roll, which has a white cap and a circular protrusion (again the white cap can be pried out with a flat head).

There was some damage to the metal axle as the metal bearing case cut slightly into the rod (you can see it in the picture below on the left where the red arrow points to the cut - it is a bit faint in the photo).

The real damage was to the plastic bearing holder.  There was a noticeable bulge and distortion caused by the heat from friction (the red arrow points to the bulge - note the distorted non circular shape of the plastic).

This was in sharp contrast to the damaged plastic bearing holder from the white end of the brush roll, which remained perfectly circular (the distorted holder is on the left and the undamaged one is on the right).

Both bearings were considerably dusty, but the bearing on the damaged side was absolutely filthy in comparison to its counterpart.  I cleaned both bearing holders with water and then lubricated the metal bearings (model ID 608Z) with silicone spray lubricant.  In particular the bearing on the damaged side was stuck badly and required a significant amount of lubricant to wash out the dirt that must have caused the bearings to seize.  Fortunately I was able to get the bearing in working order, but even if I had been unable to it would have been a simple matter to order a new one (they seem fairly cheap on eBay http://www.ebay.com/bhp/608z-bearing).

As you can see there is a large gap in the damaged bearing holder where the plastic had melted. I was able to realign the bearing in the correct position and then used JB Weld to hold the bearing in place by filling the void.  If you look at the picture above on the right you can see a thin metal washer - this was taken from the damaged bearing holder.  I ended up not putting it back in as it was too heavily warped to fit correctly.

It was just a relatively simple matter of mixing up and applying some JB Weld, then reinserting the bearing, and applying additional JB Weld to fill the remaining gap.  After letting the epoxy set in overnight I removed a little bit of the epoxy so that the bearing could spin freely.  Then it was a simple matter of putting the whole brush roll back together and now I have a much quieter vacuum (although now I will be more attentive in cleaning the brush roll and making sure that the bearings still work).
Well that sums up this repair and post.  I hope that someone finds this moderately useful.

Hello world!

Hello world!  This is the first post on my blog and hopefully the first of many (provided I remember to update this).  This blog will be primarily used to share a few repairs I make of small appliances and objects.  As such it is entirely an amateur effort, so if you are looking for in-depth step-by-step tutorials or impressive camera work then prepare for disappointment.  I only promise to do the best I can.
I should explain my philosophy towards repair, which focuses on two aspects.  First, which is to be environmentally friendly by saving some stuff from the garbage pile and second which is to save a little money by repairing old items vs buying new.  While many items could be repaired to working order, in many cases the cost of replacement parts means that it is not economically sensible to do so.  Keeping budget constraints in mind I really only do repairs where the cost of parts and materials vs. the cost of a new item makes sense.   For those items I cannot repair I generally keep them on hand for parts and such.
I should also explain my DIY repair skill level, which is strictly at an amateur level.  So you will not see any posts with super amazing electronics (I only wish my solder skills were that good).  Instead you will see just a few posts on low-level mechanical and electrical repairs.
Well I think that sums up most everything I wanted to get out of the way with the first blog post so I hope everyone enjoys my blog!