More tinkering

 Computers, Handyman, Personal  No Responses »
Jun 022022
 

I have a color laser printer that I purchased 16 years ago. (Scary.)

It is a Konica-Minolta Magicolor 2450. Its print quality is quite nice. But it is horribly noisy, and its mechanical reliability has never been great. It was only a few months old when it first failed, simply because an internal part got unlatched. (I was able to fix it and thus avoid the difficulties associated with having to ship something back that weighs at least what, 20 kilos or more?)

Since then, it has had a variety of mechanical issues but, as it turned out, essentially all of them related to solenoids that actuate mechanical parts.

When I first diagnosed this problem (yes, having a service manual certainly helped), what I noticed was that the actuated part landed on another metal part that had a soft plastic pad attached. I checked online but the purpose of these plastic pads was unclear. Perhaps to reduce noise? Well, it’s a noisy beast anyway, a few more clickety-click sounds do not make a difference. The problem was that these plastic pads liquefied over time, becoming sticky, and that caused a delay in the solenoid actuation, leading to the problems I encountered.

Or so I thought. More recently, the printer crapped out again and I figured I’d try my luck with the screwdriver one more time before I banish the poor thing to the landfill. This time around, I completely removed one of the suspect solenoids and tested it on my workbench. And that’s when it dawned on me.

The sticky pad was not there to reduce noise. It was there to eliminate contact, to provide a gap between two ferrous metal parts, which, when the solenoid is energized, themselves became magnetic and would stick together. In other words, these pads were essential to the printer’s operation.

Inelegant, I know, but I just used some sticky tape to fashion new pads. I reassembled the printer and presto: it was working like new!

Except for its duplexer. But that, too, had a solenoid in it, I remembered. So just moments ago I took the duplexer apart and performed the same surgery. I appear to have been successful: the printer now prints on both sides of a sheet without trouble.

I don’t know how long my repairs will last, but I am glad this thing has some useful life left instead of contributing to the growing piles of hazardous waste that poison our planet.

 Posted by at 1:03 pm

Thank goodness I am not claustrophobic…

 Handyman, Personal  No Responses »
Jul 032019
 

There is always a first time for everything.

I have spent more than 56 years on this planet so far, but today was the first time that I managed to lock myself in a bathroom.

I was heading to see my dentist, in a bit of a hurry when I went to the bathroom one last time and slammed the bathroom door. (I was angry because I missed the bus that would have taken me to my destination comfortably.) When I was trying to exit the bathroom, the doorknob did not function. It rotated freely, and the door remained stuck.

My wife was fortunately at home. Unfortunately, the doorknob on the other side of the door didn’t do a thing either.

I was trying to force the door open using makeshift implements. My wife was trying to do the same from the other side.

After a few minutes, I realized that I would not be able to make it to the dentist on time, so I phoned their office. They were very nice and understanding. What they thought about me is another matter.

After another fifteen minutes I was ready to give up. I resigned myself to having to spend half the afternoon in a tiny bathroom (a tiny powder room, really) as I called our condominium manager for help.

But just then, while I was talking to our condo manager, my wife succeeded. With the help of an axe and a kitchen knife, she was able to force the door open. I was free! And the door was not damaged too badly either.

Grabbing my screwdriver, I disassembled the door lock. I found that an essential part, the spindle, became detached from the knob to which it is normally attached, and ended up completely inside the other knob. Thus it could no longer perform its essential function of actuating the latch. The problem was trivial to fix.

Thank goodness I was not alone at home. Thank goodness my wife didn’t give up so easily and managed to free me. And thank goodness I am not claustrophobic.

 Posted by at 5:07 pm

TV repairman

 Electronics, Handyman, Personal  No Responses »
Mar 182018
 

Anybody interested in hiring a competent TV repairman?

No, just kidding. Nobody makes a living from TV repair anymore. (On the other hand, if you are interested in hiring a competent IT contract professional… but I digress.)

Still, I have this compulsion, trying to repair broken things even when they have little or no practical utility. So it came to be that I felt compelled to repair this old SANYO AVM-2664U analog 26″ CRT TV, with a circuit board that was buzzing louder than a hive of angry wasps, as shown in this thermal infrared video which I made while I was hunting for possible hotspots on the circuit board:

Eventually, I managed to track down the problem: One lousy little capacitor.

As I told my wife, it would be fun, doing this for a living. Unfortunately, nobody is likely to pay hundreds, maybe even thousands of dollars to repair an old television set that not even thrift stores want anymore (too heavy, too obsolete). Yet another perfectly useless skill in the year 2018.

 Posted by at 5:57 pm

Speed Queen

 Handyman, Personal, Technology  No Responses »
Dec 052017
 

Our townhouse was built in 1981 or 1982. It came with a washer and a drier installed. When we moved in, just over 20 years ago, those machines were already nearly 15 years old, but still working flawlessly.

Many years later, the washer developed a problem: A pressure regulator valve in it failed. A technician temporarily fixed it by bypassing the valve and just turning the shutoff valve to reduce the pressure. He didn’t even charge us for this work; he said he’d be back once he had a chance to order the right replacement part. He never did, and as he was one of several technicians I called from the Yellow Pages that evening, I could not even remember who he was. So I never got a chance to thank, not to mention pay, him for his labor.

The temporary solution then became permanent. The washer worked well for many more years. Until Saturday morning. Just as my wife, on her way to a craft show, was trying to wash a few freshly knitted hats, the washer refused to spin and refused to drain the tub.

I was somewhat hopeful that the cause was just a bad interlock switch, which is designed to prevent the washer from operating with the lid open. This switch stopped functioning a while back; the washer ran always, lid or no lid. But who knows, perhaps now the switch failed in the open position? I opened up the old beast, located and removed the switch and bypassed it.

It could have worked. In fact, it almost did. With the switch bypassed, the washer was no longer completely silent when it was in the spin/drain position. The motor buzzed.

But only buzzed. That angry, 60 Hz buzz that you hear when a motor is seized. And sure enough, after about 15 seconds I began to smell, and then see, acrid smoke.

This was the moment when I knew that after a remarkable 35-year run, this old White–Westinghouse washer had its last wash. It was, unfortunately, finished.

So then came the annoying task of having to find a new washer. Fortunately, I was prepared, as I already contemplated the possibility that our old washer might die (35 years!) Lately, I stumbled upon a brand: Speed Queen. It appears that they mostly make commercial washers, for laundromats and other commercial installations. But they do have a few home models.

Oh, they are pricey. More than two and a half times as expensive as the cheapest washer that you can find. Still… based on the reviews I read, I thought that it might be worth the price. When I make a purchase, I either buy cheap (and then I know that I am buying cheap) or buy quality. Now quality is not always available. And often, reputable brand names turn out to be just pretty labels attached to the same cheap, er, excrement that is sold under other names at half the price.

So Sunday, we went to see this washer in person, at a local appliance store that carries the brand. The comparison was convincing. The weight difference alone between the Speed Queen and other washers was revealing. And of course it was a top loader with mechanical controls, a rarity nowadays, but the kind of machine that is precisely my wife’s preference when washing freshly made wool hats, mittens and such in her own special way.

So we opted to buy the Speed Queen, and it was delivered earlier today. Installation was my job. It’s not very hard; you hook up the hot and cold water, install the drain hose, level the machine and power it up. It powered up nicely, and the first test wash went like a charm.

So here we are, with a brand new, yet very conventional, high quality washer installed right next to a 35-year old clothes drier that still works reliably, and now that I cleaned it, looks almost new.

What can I say… apart from the damage to my wallet, it was a fun day. I am glad it happened now, not a few weeks ago when I was struggling to meet some deadlines, having freshly recovered from the flu.

Will this machine last 35 years? Who knows. But I certainly hope that we won’t have to worry about buying another washer for a long time to come.

Oh, and the package contained an interesting surprise: An order sheet for the parts manual and service manual for this model. I think I will buy those. I hope the machine will never need repairs, but if it does and it’s no longer under warranty, maybe I can fix it. Often the hardest bit is knowing what to do, and that’s where a factory service manual can be of immense help.

 Posted by at 10:00 pm

Vacuum cleaner modding

 Handyman, Hungary, Personal  No Responses »
Nov 262017
 

OK, so today was a Sunday, I have recently finished some projects, so I had a bit of time to work on long overdue things around the house. Actually, it had to do with an attempt to repair an old TV, which needed to be vacuumed first, as it contained more than two decades’ worth of accumulated dust. But quickly, my attention turned to our vacuum cleaner instead.

It is a Kenmore vacuum cleaner, one of the house brands of soon-to-be-defunct Sears Canada. It is reasonably decent. But…

Well, it has a HEPA filter. It is supposed to filter the exhaust of the vacuum, to ensure that it contains no microscopic particles. The HEPA filter is a small rectangular piece made of cardboard and other materials that fits behind a cover on the back of the vacuum. The vacuum was barely a few weeks old when this cover first fell off. Putting it back on didn’t help; it fell off increasingly often. Taping it on didn’t do the trick either. Eventually, I affixed it with two screws, and it seemed to hold afterwards. Even then though, I had a nagging suspicion that there is something odd about this vacuum cleaner…

But first, let me digress. Let me mention a building, a six-story apartment building in the Hungarian city of Pécs, which is the building where my wife grew up. This building is odd, as its stairwell and elevator shaft are housed in an entirely separate building, connected to the main building on each level by a hanging corridor. Rumor has it that the original architect simply forgot to include a stairwell and elevator shaft in the design. Kind of hard to believe but…

Anyhow, back to my vacuum cleaner. My nagging suspicion was this: after the air goes through the HEPA filter, where does it go? It is surely not going to exhaust through the solid plastic filter cover (the one that kept falling off.)

Lately, our vacuum cleaner was making weird noises. When I looked at it more closely today, I noticed that one of the screws that I used to affix the HEPA filter cover was gone, and that the filter cover was slightly off. The weird noise was the air whistling through the resulting gap. Well… this did it. Hard as it is to believe, I was forced to conclude that whoever designed this vacuum cleaner forgot to include an exhaust in the design.

Out came my trusty drill (bought at a Sears store eons ago when Sears was still the best source for quality tools) and a few minutes later, the filter cover had a bunch of holes in it:

I put the cover back on, affixed it with screws again, and tested the vacuum cleaner. It was working just fine, running more smoothly than ever, and significantly cooler to the touch than ever before. And when you put your hands over the holes that I made, you could feel the tremendous outrush of air… air that previously had no place to go other than exhausting through cracks between plastic bits. No wonder the pressure was high enough to push off the HEPA filter cover even when screws were holding it in place.

Before writing this blog entry, just to be sure, I double checked. I don’t want to make a fool of myself after all. But no… there truly is no exhaust, none whatsoever, on this vacuum cleaner.

What engineer in his right mind designs a vacuum cleaner with no exhaust?

Hmmm. Maybe an engineer from the same school that trained the architect who designs buildings without stairwells.

 Posted by at 11:03 pm

TV repair

 Canada, Electronics, Handyman, Personal  No Responses »
Nov 262017
 

Yesterday, I went grocery shopping.

I came home with groceries and a TV.

You see, Loblaws was selling cheap 32″ smart TVs at the checkout counter. Only 150 dollars (Canadian), and they even paid the sales tax.

We were in need of a TV. The TV that we have in the bedroom (rarely used, but good to have; it’d have been nice earlier this month, when I spent a few extra hours in bed on account of feeling miserably sick) is old, useless and broken. Useless because it’s an analog TV, and there is no analog service anymore, nor do we have an extra settop box for upstairs. And broken because… well, even when it was still actively in use, we needed to whack it every so often, as after it warmed up a little, its picture became elongated and discolored… but a good, well-aimed whack fixed it. Lately though, the picture was permanently distorted and in addition, the TV made a horrible, rattling, buzzing sound (and no, it didn’t come from its speakers.)

Anyhow, we now have a new TV in the bedroom. It picks up OTA digital channels just fine using a small antenna, and it works well with Netflix and YouTube. Perfect. And I managed to haul the old TV downstairs this morning. (It’s incredible just how heavy these larger old CRT televisions are.)

Before throwing it out, I decided to open it up. Who knows, maybe I can fix it and in that case, it can still have a second life at the Salvation Army or whatever. The later it becomes landfill, the better for all of us. So I decided to check this old beast’s innards. Which, in case anyone is wondering, looks like this (yes, I took several pictures just in case I disconnect something that needs to be reconnected the right way):

After removing the back cover and then vacuuming out a few pounds of accumulated dust, I powered it on, listening for the buzz. I also looked at the circuit board using my IR camera. My attention was quickly drawn to the left side, where there are some rather hot parts, but that turned out to be a bit of a red herring: the hottest part is a high-wattage resistor that is meant to shed a lot of heat. Next to it though… what I thought was an inductor turned out to be a relay. And that’s what appears to be rattling!

I checked online. Surprisingly, this is a standard part, not model-specific, still being sold. But the first price I saw was something like $12.50 US plus shipping. Way too much to invest into a 23 year old CRT television set. But then… I found an offer from China for the princely sum of 75 US cents, plus 35 cents shipping. $1.10 in total. Of course I ordered it.

So now I wait. When the part arrives, I’ll attempt surgery. If it fixes the TV, we’ll find a good home for it. If not… landfill, landfill, here we come.

Incidentally, this television set was assembled in Canada. How about that. I don’t think there are many television sets assembled in Canada these days.

 Posted by at 10:45 pm

Printer repair

 Computers, Handyman  No Responses »
Sep 122017
 

I have an old (11 years, to be precise) Konica-Minolta magicolor 2450 laser printer, with the duplexer option.

The quality of this printer’s output is superb, but mechanically, it was never perfect. Just a few weeks after I purchased it, it stopped printing. Faced with the prospect of having to return a 20+ kilo monster, I figured I’d take my chances and look for the cause; after partially disassembling the printer and re-seating some internal mechanical parts, it started printing again.

It worked for many years, but it was becoming rather unreliable. Sometimes, the output was shifted down from the top margin. Paper jams became frequent. It started to fail in mysterious ways, such as complaining that a toner cartridge was missing. Eventually, it stopped printing altogether; every attempt resulted in a paper jam, as the last set of rollers, responsible for pulling the paper out of the printer, no longer worked.

I bought another printer in the meantime, so I retired the mc2450. But I loathed the idea of turning it into e-waste or sending it to a landfill. Today, I decided to take one final look at this fine machine, to figure out what could possible be wrong with its mechanism.

Eventually, I stumbled upon a set of YouTube videos, which offered advice about cleaning some solenoids. Say again?

Solenoids are used in some internal actuators that turn on and off specific parts of the printer’s mechanism. These events are timed with precision. And as it turns out, little plastic pads that are used, I presume, to eliminate clicking sounds and perhaps reduce mechanical wear in the metal parts that are actuated by the solenoids became sticky over time. Just a teeny bit sticky. But that teeny bit is enough for the actuator to become a little lazy. Move a little too slowly. Not much… a few ten milliseconds. But when the paper moves through the printer at, say, 20 cm/s, 50 milliseconds amounts to a centimeter… more than enough for timings to be off and for the mechanism to fail.

Still, it sounded like a stretch. After all, the stickiness was just barely noticeable. Nonetheless… I followed the video’s advice (except that instead of removing/replacing the plastic pad in question, I covered them with kaptonthread seal* tape.) After I reassembled and fired up the printer (and fixed a paper weight adjustment that I managed to set incorrectly), presto: it was printing test pages flawlessly!

Yippie. My old printer was working again. I put it fully back together, and decided to give it another test, this time with its duplexer installed. A huge disappointment: as the paper was feeding through the duplexer, it acquired a nasty fold, very consistently, each and every page. What could possibly cause this?

By this time, I downloaded the service manual for this printer, and studied the diagram of the duplexer a little. It looks deceptively simple, just like an extra back cover for the printer, but it hides complex machinery inside. And guess what… a solenoid actuator, too. And when I disassembled the duplexer and looked at the bit in question, sure enough, its plastic pad was sticky. Ever so slightly sticky, but the stickiness was (just barely) noticeable.

Another few square millimeters of thread seal tape later, after reassembly, my old printer is now printing double-sided documents again flawlessly.

This exercise was not just satisfying but also very educational. That such a tiny flaw can cause all these symptoms. And symptoms that I attributed to (possibly) bad sensors, misaligned or failing mechanical bits, or aging plastic were all caused by actuators that were slowed down, by no more than a few ten milliseconds, tops, by a bit of sticky plastic. Amazing.

*Someone told me it was kapton tape. No, it’s really teflon. My mistake.

 Posted by at 11:40 pm

Handyman again

 Handyman, Personal  No Responses »
Sep 272012
 

Once again, I was doing something dangerous: despite being a programmer, I chose to carry not just a screwdriver but also some power tools.

Two weeks ago, I had a plumbing crew remove our old bathtub. It was way overdue:

It took them no more than a couple of hours to reduce the bathtub to this:

And by mid-afternoon, they were done. The new bathtub was installed. Actually, let me emphasize: ONLY the new bathtub was installed:

From this point on, I was on my own. It was by choice: I dislike having workmen in my house and in any case, these are skills that, I think, are well worth learning.

Having never done tiles (or for that matter, sheet rock) before, I was taking things slowly. (Hey, I am also just a few months shy of fifty, somewhat overweight, and I usually spend my days in an armchair sitting in front of a computer.) Even so, a few days later, I was done with all the preliminary work: notably, the installation of tile backer drywall:

The plastic sheets were put in there so that we could use the bathroom even while it was still under construction.

Next came the tiles. The tricky bit (for me anyway) was to cut tiles around the faucet and other fixtures. I was able to cut pretty decent holes using a tile cutter bit in my “Roto-ZIP” tool:

And thus it came to be that a little less than two weeks after the plumbers left, the tiling was done:

There was, of course, still more work to do. First, I had to wait a few days for the adhesive to set before grouting the tiles. Once I completed the grouting successfully, I had to wait another few days before I could spray the new grout with sealant. It was only at this point, namely today, that I sealed the edges of the tile using silicone. Finally, once the fixtures were reattached, the job was at last done:

Needless to say, I am mighty proud of myself. In fact, I’ll probably be insufferably proud for the next few days (that is, unless the tiles start popping off, in which case my insufferable pride will rapidly turn into an overwhelming sense of embarrassment.) There is still a little bit of cleaning up to do, and eventually, repaired bits of wall around the tiles will need to be repainted. I may apply a bit of paint for protection, but the real paintjob will have to wait; I am considering replacing the vanity (the sink definitely needs to be replaced) and I am also considering replacing the floor tiles, which are old and have developed a few minor cracks over the years.

But not this year. For now, I prefer to return to my regularly scheduled programming job and put down my screwdriver.

Phew!

 Posted by at 5:32 pm

Handyman

 Handyman, Personal  No Responses »
Oct 302010
 

I am 47 years old, but up until last week, I never ever painted a room. I knew more about how paints behave on spacecraft surfaces than on drywall.

Well, this is no longer true. I just finished the walls, window, door, and floor in our small bedroom:

Yes, I am proud of my handiwork. Our cats appear to be satisfied, too:

But no, I am not planning to give up my day job.

 Posted by at 5:51 pm

My brand new toilet

 Handyman, Personal  No Responses »
Sep 262009
 

I was a very brave person today… I peed in a toilet that I just finished installing.

So far, no sign of leaks below.

 Posted by at 1:05 am

The toilet saga, part 2

 Handyman, Personal  No Responses »
Sep 252009
 

I’m most pleased with myself tonight. Maybe I have an aptitude for the experimental side of physics, too, as it appears that I was able to repair successfully my subfloor around the leaky toilet. I took some pictures:

Next task is to finish the floor and put the new toilet in. Maybe tomorrow, maybe not… I’m rather tired, so I might skip a day. But then again, I seem to be on a roll…

 Posted by at 2:18 am

Computers, physics, and leaky toilets

 Handyman, Personal, Physics  No Responses »
Sep 242009
 

There are certain areas of life where decades of computer expertise are quite useless, and even a reasonably thorough knowledge of theoretical physics is only of marginal use. Replacing the rotted subfloor around a leaky toilet is one such area.

Yet this is what I am presently engaged in. So far so good… using some rather evil, foul-sounding power tools, I managed to cut out much of a square hole around the drainpipe, I’m only having trouble with some corners where the power tools don’t reach. Unfortunately, I found out that the subfloor in this bathroom is actually an inch thick, as opposed to the standard, 5/8″ board that I already bought… oh well, it wasn’t a big expense anyway, and perhaps I can use that board for some other purpose later on.

For now, it’s back to Home Depot to get a piece of inch-thick wood and also some advice on cutting out those nasty corners. Maybe they can suggest a method that would be slightly more efficient than the hammer-and-chisel approach which I attempted, with  some limited success.

While I’m at it, I shall also inquire as to whether it is possible for them to cut my boards to shape to fit around the drainpipe, so that I wouldn’t have to attempt such precision cutting using my fairly limited skills and perhaps less-than-adequate set of tools. Not to mention that I value my fingers, and prefer to have all ten of them in the right place and in full working order after I’m done with all this…

But for now, it’s rest time. I have this nasty tensor algebra program to tackle, but no matter how difficult it is, I sweat a lot less doing it than when I’m cutting a subfloor with a circular saw.

 Posted by at 3:30 pm