Category: appliance repair/installation

This morning’s wsj 6/21/17 first page article says “Bust Your Phone Again?  These Teens Are Here To Help”.  A 16 year old Nantucket resident instead of surfing, made close to $24k last summer repairing smart phones and is busy again this summer.  His charge to repair a cracked iPhone 7 Plus is $189.99.  

M. dropped her iPhone 4 last week and the screen is hard to read – see pic above.  She wants to wait for the new iPhone due later this year.  So I suggested I would try repair it.  On the internet retail giant’s website we ordered a kit comprising new screen and repair tool kit for approximately $17 plus tax.  The iPhone 4 is an old phone so replacement parts are reasonably priced.  Our phone is a Verizon phone which is different from AT&T, so it was important to order the right screen and also to follow YouTube instructions for the Verizon/Sprint phone not the AT&T. 

The kit arrived and following the excellent tutorial I began dismantling the phone.  There are lots of tiny screws and to keep track I followed a suggestion to sketch an outline of the phone and tape the screws and parts to the location where they belonged.

I quickly encountered a problem – the Phillips screwdriver provided with the kit was not up to the task.  So I stalled for a day and visited a computer store to inspect their screwdrivers.  The size I needed was a Phillips PH000 and there were lots to choose from.  I settled for a kit made in Taiwan made of chrome-molybdenum, described as professional, with an ISO certification.  Perhaps all these plugs would help.  And they did – no more problems with screws.  And then I stalled again until I read this morning’s wsj article and, fired up, I resumed.

To get to the screen a whole lot of parts have to be disassembled.  Not for those faint of heart, or with unsteady hands or blurring close up vision or impatient to get the job done.  I could tick some of these boxes.

A hair dryer was conscripted to soften adhesive and then the old cracked screen was off and the new screen installed.  On the re-assembly road back I was too confident and went too quickly and missed a few steps and had to backtrack, which was frustrating.  But eventually all the components were in place and the critical moment arrived – would it power on and make and receive a call, and it did.

My tractor building has roll-up door on one end and a 4×5 ft window at the other end.  It is insulated glass in a steel frame.  And has been fine until yesterday when I backed my Case tractor with pto chipper into it, and it shattered.

Up till then I had a good morning.  My bobcat started instantly and I turned the compost heap and then I chipped a lot of small trees and branches.  And feeling good about everything I then reversed my chipper through the window.  I designed the building to accommodate a tractor.  Then because I am lazy I left the chipper attached.  But even then there was 10 ft to spare. But now I also put the bobcat into the building with its bucket neatly slotted into the tractor’s bucket and a total of 3 inches to spare.  But 3 inches is insufficient margin when you are tired and edging back  a 9,000 lb old workhorse (Case IH 585 plus bucket plus chipper plus water filled tires).

So what to do?  I have not been successful cutting glass and decided rather than do it myself to call a professional.  I tried 3 local outfits which all had decent websites.  I sent a pic (see above) to one and they said $589 with 50% upfront deposit.  Another estimated $340 for plate glass and $370 for tempered glass, 0.25″ thick, but there was a wait of at least 2 weeks.   The third estimated $365 and a 3 day wait.  The 2nd and 3rd quotes did not see a pic of the window and I was concerned that their cost would be higher.

So I decided to research.  What about acrylic rather than glass?  I learned the pros and cons of plexiglass vs glass.  Glass is cheaper, scratch resistant, easier to recycle.  Plexiglass is more transparent (lets thro more light), lighter, more resistant to breaking and shattering and easier to work with.  I became interested in plexiglass.  An internet provider could cut plexiglass to my dimensions to .0625″ accuracy for $180.  But shipping was an additional $125.  I asked if I could pickup from their Atlanta location and avoid the delivery charge, but did not hear back.  I web visited Lowes and HD,  and HD had 4×8 ft acrylic sheet 0.25″ thick for $185.  I would have to do the cutting myself.  I googled how to cut plexiglass and different methods were suggested.  I decided to use my circular saw with fine tooth blade and a straight edge secured with G-clamps to guide the saw.

This morning at HD I bought 4×8 ft plywood sheeting 19/32″ ($20) and the 4×8 ft acrylic 0.25″ thick sheet ($185) and a 7.25″ 140 teeth circular saw blade ($6) – all before taxes.  And got to work.

First to remove the broken glass.  With thick gloves and eye protection I was still disconcerted when the glass would suddenly shatter and spray.  So with an 8 ft 4×4 I just smashed out the glass.  Removing rusted Phillips screws, which secured steel u-channels holding glass in frame, was initially difficult.  Then I figured a solution – full weight on heavy portable drill with newly inserted Phillips driver heads and quick nudges on the trigger got them turning.

The metal u-channels were wedged in tightly but with patience they came out and the remaining glass shards and the spacer which separated the original 2 panes of glass.

I cautiously approached the cutting of the acrylic sheet.  How this one 4×8 ft 0.25″ acrylic sheet could cost $185 (before taxes) boggled my mind.  Since I only had one chance to get it right, I didn’t want to mess up.  The metal frame measured 48 & 1/16″ by 60 & 1/16″.  The acrylic sheet was 48 & 1/16″ wide.  So I pre-cut some surplus wood panel to 48″ but it didn’t fit.  I know the recommendation is to deduct 1/8″ from width and length.  But I also wanted room for expansion in summer.  The u-channels are 0.5″ high, so with all this considered, I decided to cut to 47.75″ by 59.75″.  But first I practiced on surplus plexiglass and then after lots of scratchings and calculations, I went for it.  And it fitted just right. 

However the u-channels were too tight to fit so I ground down each end on my grinder.  I added some spacers between the u-channels and the acrylic.  All that remains is to seal the acrylic edges with silicone and add permanent spacers.  And remove all the broken glass which according to an online calculator weighs 120 lbs.  Broken on Monday and replaced on Tuesday, with a significant cost saving, some satisfaction, and a more resilient solution.

And for the time being I fitted the bobcat closer to the tractor by placing its bucket above the tractor’s bucket rather than inside it.  But I will detach the pto shredder from the tractor and store it elsewhere so I have more space in the building.

In July 1998 I installed an undersink filter.  I know the date because I kept the original installation instructions.  I remember the accompanying written warning but paid little attention:  “To prevent costly repairs or possible water damage we strongly recommend that the housing be replaced periodically: every five years for clear tanks, and every ten years for opaque tanks.  If your housing has been in use for more than the recommended period, it should be replaced immediately”.

Imagine my surprise and dismay in November 2016 when, upon returning to the house, we noticed water in the garage coming from the entrance way which leads to the kitchen, and the kitchen and most of the dining room floors covered with water.  Yup, as the above picture shows, the bottom of one of the housings had separated and its failure produced a mini flood.

Busy I was with a commercial carpet cleaner vacuuming up the water on a non stop basis for several hours.  Then with fans and the heaters to dry the carpets.  Over the next 24 hours we were reasonably successful, except for the entrance where the underlay and the concrete floor were so wet they stayed damp and began to smell.  I lifted the carpet and underlay/pad and continued heating the area until the foundation had dried.  Then installed a new underlay and re-installed the carpet.  So normalcy returned and we were fortunate we had carpet and tile rather than wood floors.

My communications with the manufacturers made little headway.  The new housings they carried would not fit the old base so they could not offer a goodwill replacement.  And they courteously reminded me of the warning to replace the housing within 10 years of installation.  I could not argue.

I bought a new undersink filter with just a single cartridge.  We had previously needed a 2 cartridge system but with sediment no longer an issue, a high quality chlorine eliminator filter was all that was needed.  And the water bill for that month showed unusual usage of close to 1,000 gallons.  So, if you have an undersink filter, remember to replace the housings timely.

In my previous post (part 1) I describe the temporary repair I made to the expansion tank pressure switch.  However the pipe/nipple connecting the pressure switch to the water manifold is badly rusted and seeping water and just a matter of time before it disintegrates.

I want the repair to proceed efficiently and so I researched how to removed broken nipples – Bob’s plumbing video (how to remove a broken pipe) was very helpful.  So prior to commencing the repair I bought and assembled all the tools and parts I would need – new pressure gauge; new pressure switch set for range 30psi to 50psi; 4″ long 0.25″ diameter brass pipe; an extractor kit for broken pipes; assortment of brushes to clean threads; rust penetrant oil; and my usual assortment of standby tools.  And then off to the well head.

Caution – following involves working with 240 volts and can result in serious injury or death and should not be undertaken by anyone not competent in this area.

I first switched off the power, then removed dome and pressure switch cover and photographed the wires so I could remember later which were connected to which.  With a tire gauge I measured the air pressure in the expansion tank – it was 45psi.  I opened a faucet and drained the water from the expansion tank.  Then I looked at the nipple and, as previously mentioned, it was in bad shape.

After dowsing with rust penetrating oil I tried gently undoing the nipple from manifold and it turned for a bit and then broke away leaving some pipe in the hole.

With my nipple extractor the rest of the pipe in the hole appeared to disintegrate and I then cleaned the female threads with brass brushes.  While I was at it I also removed the broken water gauge.

And installed a new gauge and was disconcerted to see that somehow I had cracked the glass cover.  I used pipe thread sealant and connected up the  new pressure switch and pressure gauge.

And then switched on the power and watched the gauge rise to 50psi and heard the switch click open and stop the pump.  Everything was working fine.  I checked the expansion tank pressure with my tire gauge and it was 45psi.  Mission accomplished.

 

Unexpectedly, Friday evening, no water in the house.  No warning signs such as discolored water which could indicate the well was running dry.  Checked the power supply board and the switch was on.  Called the well repair guy and asked if any wells were running dry.  He said 12 in the mountains but none at my level and he would visit Saturday 6pm.

Caution – following involves working with 240 volts and can result in serious injury or death and should not be undertaken by anyone not competent in this area.

Saturday morning I lifted the dome cover over the wellhead and removed the cover over the wires.

Yes, the wires from the house were carrying 240 volts.  I then switched off the power.  So what could be the problem?  The well is about 400 feet deep and that’s where the pump is located.  The problem could be a break in wires to pump, pump itself, water pipe from pump to surface or from wellhead to house, or worst case, a dry well.  The the pump was pulled and replaced in 2007 – cost $1,200.  Pumps usually last longer but ground lightning strikes can prematurely age a pump.  My neighbors well ran dry a few years ago and to drill, fracture and install a new well cost around $12,000.  The potential costs could be high.

The ground from wellhead to house was rock solid dry which is what you get in the extreme drought situation in north Georgia – so no leak between wellhead and house.  While I was at it I walked over the septic tank and pipeline area and it was dry, so no ongoing leak in the house draining the well.

Back to the wellhead.  Could there be another issue?  The expansion tank for this well is located at the wellhead.  The function of the expansion tank is to extend the life of the pump by holding reserve water under pressure for the house and when the water pressure in the tank falls below a set level it then switches on the pump.  Typically it switches on the pump when the pressure falls to 30 psi and switches off the pump when the pressure reaches 50psi.   Thus the life of the pump is extended since it does not have to cycle on and off every time water is used in the house.   The expansion tank is connected to a pressure switch which is normally in the closed (on) position and it opens (cuts power off) when the expansion tank is fully charged.   I looked more closely at the switch and noticed the plate which should be closed when water is needed was loose and not touching and providing continuity to the terminals (if you look carefully you will see there is no contact between the plate and the terminals).

There is a spring which holds the plate to the terminals and it must have broken and was not in sight.  It seemed there were 2 ways forward – replace the entire switch or just the spring.  The small pipe called a nipple, which connects the switch to the main pipe is badly corroded and I am quite sure will not come undone without disintegrating.

I wanted a quicker fix for the time being and decided to try replacing the spring.  Fortunately I have a spare previously used switch and so I headed to my workroom and, after brewing a fresh mug of coffee, began dismantling the spare switch to figure out how to access the spring which is below several other parts, and how to re-assemble it.  First attempt took about 20 mins, second attempt 10 mins, and by 4th attempt I could do it from any angle in about 5 mins.  I removed the spring and some adjacent parts from the spare switch and headed back to the wellhead.  And about 10 mins later the switch was repaired and I switched back on the power and the house received water and, as expected, once the expansion tank was charged, the switch snapped open.

So the switch appears to work ok and I canceled the visit from the well repair guy, and I am now thinking how I will remove and replace the corroded pipe.  See part 2.

I have an old Sears Scroll Saw:

The manual is dated October ’92 so I must have purchased the scroll saw in the early 90’s.  It worked fine though I did not use it much.  Recently I had need for it but there was no response when I plugged it in.

Notice: If you are not competent with electricity do no attempt anything mentioned below – serious harm or death can result – instead seek professional assistance for your electrical problem.

I removed the base plate to expose the circuit board and checked: a) was power reaching the circuit board (yes); b) was the on/off switch functioning (yes); c) was there a fuse which may have shorted (no); d) was power being output to the motor (no).   Conclusion – the circuit board was receiving power, no fuse had shorted, the on off switch worked fine and no power was output to the motor which drives the saw.  So the motor was fine and there was a problem with the circuit board.

Elsewhere on this website I describe how I shipped circuit boards of an oven and a refrigerator to a specialist firm for repair.  Also how I have replaced capacitors of air conditioning units.  And how I replaced the fuse of a Bose cd/radio.  But I have never repaired a circuit board.  So time for a new challenge.

The beauty of old appliances is their circuit boards appear simple and are easier to work with than the modern stuff.  The pcb (printed circuit board) of the Scroll Saw has relatively few components:

Here is a better pic with the connectors removed:

Some pcb’s have a numbering system for each of the components – not this one.  The big green device on the right is the on/off switch.  The 3 barrel looking devices with the silver tops are the capacitors – there usually is a problem with one of them.  Then there are a number of resistors and diodes and several transistors (some covered in glue) and on the left, just above TOTY a thyristor with 3 legs.  The rectangular horizontal white object at the top is a resistor and the rectangular vertical white object is a capacitor. Plus other items such as a varistor and pots.

You will notice on bottom right a number E1?9744.  I hoped to find a schematic of this pcb on the web and fruitlessly googled this number which I thought was E119744 or some other combination.  To no avail.  Testing and replacing components is ok but I would much rather understand how the power supply actually works.  I have a 1991 Radio Shack booklet on “Building Power Supplies” (compatible lineage) which was helpful explaining the principles of PWM etc. but even then I could not figure out how this particular pcb worked.

I thought the only way to test a capacitor is to unsolder and remove one of the legs from the circuit.  I did this with the large cap (470 micron Farads) next to the switch, and it was fine, but what a pain for testing.  Then I learned about ESR meters which can test caps seated on the pcb.  Much easier.  And guess what – the cap at the bottom (47 micron Farads) was defective.  I placed an order for a replacement cap and got instead a 4.7 micron Farads cap.  So I found an old pcb (one of my sons collected them) and unsoldered a 47 micron Farad cap and it tested fine and I installed it.

Here is an underside view of the pcb:

My next focus of interest was the thyristor the rectangular white object visible through the board cutout on the left of the picture.  I surmised that the cut out was to allow the thyristor to be attached to a heat sink which would dissipate the heat generated during operation and therefore the non presence of a heat sink could have contributed to its failure.  Design flaw?

From the topside view you can see the thyristor has 3 legs – a collector, emitter and base.  No current flows unless voltage is applied to the base.  When this occurs the thyristor should latch which means that when the voltage is removed from the base, the current continues to flow from collector to emitter.  I unsoldered the thyristor and tested it and when base voltage was removed current stopped flowing from collector to emitter.  It was defective.  I ordered and installed a new thyristor (fortunately the defective component had sufficient information for identification).

I thought the pcb should work but it didn’t.  I was stumped.  I retested the components – all fine.  Rather than mess with 120 VAC I connected the pcb to 24VAC – less chance of electrocution.  And, unexpectedly instead of getting <1 VDC I suddenly got 16 VDC.  I re-installed the pcb connected the power and, it didn’t work, back to <1VDC.  A lot of head scratching and I concluded that one of my soldered joints must be faulty.  Reconnected to 24VAC and gently pressed with a gloved finger each of the components – the voltmeter stayed below 1VDC.  Then I pressed the thyristor and the meter showed >16VDC.  Solution.  On examination one of the legs was cold soldered so I resoldered it and got my >16VDS with the 24VAC supply.  Reinstalled the pcb and connected to mains power and it works.  The scroll saw is back in operation!