For over 50 years there was a company that did market schematics for much of the electronic gear. Sam's Photofacts. In the late 1960's and early 70's I bought a lot of them to service the CB radios.
The radios were in the $ 150 and mostly $ 250 and up price range. That was when many in the area were making about $ 2.50 $ 4.00 an hour. So they would pay $ 20 to $ 50 to get the sets repaired. I did it as partly a learning and hobby, not my regular job. Then the radios started selling for $ 50 to $ 150 so not much need to repair them, and then many people quit using them.
Now with labor and parts and buildings for a shop being what they are to make any money one has to be charging from $ 50 to $ 100 an hour to come out.
For a while many items were made with common parts that were easy to replace, now just about every electronic device has a few IC chips in them and they are not easy to come by or replace.
No. Finding out via the schematic which pin connects to a switcher circuitry to enable a start is all that's needed. Without a schematic you can only try whether a CPU swap makes it work again.
If a device costs $1k and a schematic eanbles you (or a shop) to repair it in under 30mins it does make sense.
We also need to think about ecological consequences. Example: Bought a clock radio for aruond $10. Came home, plugged in, several segmetns in the LED display were dead. Hurumph! Opened it up, spent about 20mins repairing some cold solder joints, done. It still works after more than
20 years. The alternative would have been this:
Driving to the store, 30mins. Standing in line for the return, 5mins. Drive back home, 30mins. What is better, 65mins or 20mins? Oh, and then there is the matter of a gallon of gasoline that I avoided burning. Besides, this radio would have landed in the trash and I do not like to unneccesarily pollute our environment or that of others. We all have to do our part.
Why is it that _all_ my ham rdaio gear came with schematics and service manuals?
Same with radio and TV set up into the 70's. My wife's big cassic Saba
8100 stereo from the 70's developed an issue. Thanks to the availabilty of a full serice manual with schematics I was able to quickly diagnose and repair it. FM reception was restored and we still use it every day in the living room.
Well, let's hope. WRT computers I have left that era behind me when Windows 7 was called off. They are all on Linux now.
Not really. It would open up chances for new business, the neighborhood repair guy. You wouldn't believe how many people I met who open and close their garage doors by hand because the electric opener has gone bad. "I don't have that kind of money". Often it's just a corroded DIP switch, relay or the RF transistor has gone bad after a thunderstorm years ago.
I repaired the (back then painfully expensive) Grundig Satellite allband radio of my geography teacher. The TV shop had given up but it was easy. One of the IF coils had no conductivity. Took the can off, copper had oxydized away. New winding, align it, done. And I was just a school kid.
Without a schematic this would have been much tougher.
The older cars were always needing something. Oil changes, plugs, points, valve adjustments, starters.
Now about all that is done for many cars is an oil change and tire rotation or tires. Maybe brakes.
I put 200,000 miles on a Toyota and breaks, 2 or 3 changes of the sparkplugs, oil changes and the timing belt, water pump replaced at that time as it was behind the internal belt to be safe and a few light bulbs was all that was needed other than an sensor that quit at 130,000 miles.
Do you have several thousand dollars worth of test equipment to use to find the problem on the modern sets ? Another few hundred for equipmant to work on the SMD parts. For the older tube equipment like my Heathkit setup one can get by with much less expensive test equipment.
I do for my ham radios as it is mainly a hobby for me. Most of the test equipment is not new, but works well. For example I have a service monitor that cost about $ 50,000 when new in the 1990's . Bought it for $ 900 about 10 years ago as it was for the old analog cell phones and not much use to them now. Not many are going to spend $ 5,000 to $
10,000 for a service monitor test set to repair a $ 1500 radio.
Exactly. And the prices of kit keep falling. The repair-replace price point keeps moving upwards.
My current design consists of a sandwich of boards, components on both sides, wired together along the edge. To troubleshoot it AFTER manufacture requires you to separate the boards (break all of those electrical connections), fit them into a fixture, then reconnect the boards with *both* sides accessible.
[They aren't intended to be serviced after assembled as it costs too much for all but a pacrim depot to do that]
Or, you can just buy a replacement. (warranty service is simple replacement so why bother with any other approach?)
The cost of replacement is small compared to the cost of determining the device to be faulty, accessing the device and shipping it off for repair/replace.
Where I worked we had some software to pogram some equipment. We had to pay for each piece of software. To be sure we did not install the software on several laptops there was a 'key'. You could install the software on all the computes you wanted. However there was only one key. You loaded the key on the computer you wanted to use, then if you wanted to use another computer, you downloaded the key to a floppy and then onto the next computer.
Microsoft has many of their products that work similar. It is done by the internet. You install the software then get onthe internet and register it with them. That is part of what that COA or what ever that sticker on the side of most computers that run windows is for.
Sometimes there are people that can get around most of this, but for the mass of people it offers some protection.
Actually, yes. the good old boat anchors and they work well.
All I need is a Weller station ($100, alrdady had it), an ETS tip for that ($5), 2.50 reader glasses ($1 at the Dollar store). When growing older I also needed a head loupe ($20). That's it.
Even today you can. Most faults can be diagnosed with the ehlp of other ham gear and a 2-channel oscilloscope.
Exactly! That's how I got almost all my gear.
You don't need that. A dip meter, a multimeter, a function generator and a scope can go a long ways. If you want to get serious buy some boat anchors at a hamfest.
A friend has a transceiver the microphone quit working . He got on the internet and found there were 3 or 4 capacitors that often go bad. He brought it over. I had the capacitors, so started working on the mic. Had to unsolder about 6 pins that seperated the top board from the bottom board to replace the capacitors. Had they been on the top board, it would have taken about 10 minutes. As it was, took close to an hour to do the repair. At the normal $ 100 an hour many places charge and $
10 or more postage each way, a new mic would probably cost the same or less.
He got the work done for free as we do lots of things for each other. I even ate the cost of the capacitors which only cost me a buck or two the way I buy and keep parts.
I have never been to places out west, but have heard that they were charging a deposit on many of the drink bottles or no plastic bottles sold around the national parks. This was to reduce littering.
You can get some very nice test gear from China now for low prices that would have cost thousands only 10 or so years ago.
That Harbor Freight meter that used to be 'free' and some now that cost less than $ 30 are more accurate than the old Simpson 260 I have. I know that sometimes the analog meter is beter for some things and use it alot even though I have a nice Fluke multimeter.
It all depends on what you want to do. I keep up a couple of repeaters and to set them up and tune the duplexers it makes it very nice to have the correct gear. What used to take me all day, I can now do it in half an hour. Such as I used to hook a scope across the discriminator and use a Ht to get a base line and one up and down 5 kHZ to set the deviation of the FM gear. Now it is just punch a button on the service monitor.
I do have 2 boat anchor stations. One is the Heathkit sb-101 and sb301/sb400. What might have been a decent station when I was first licensed. The other is a Viking ll and Hamurlaund HQ 140 that was what a decent equiped station would be around the time I was born. The main station is an Icom 746pro and Drake L4B amp. Most of it picked up at hamfests for not too much money except the Icom was bought new about 15 years ago. Starting to think that is almost boat anchor age now.
I suspect that would have little effect. If I forget to redeem my deposit before I leave the park, can I bring the bottle to my neighborhood grocer to be reimbursed?
So, the "deposit" is just there to help fund the crews that have to clean up the mess from park visitors.
["It's not *my* yard so what do I care about keeping it free of litter? They've GOT PEOPLE to do this sort of cleanup..."]
There's a video here of a farmer discussing right to repair his farm equipment. It's about 11 1/2 minutes.
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It's been a few years since I was at the Nebraska State Fair. The special cash price of a combine sitting there that day was $529,187. That was just the combine. The 12 row corn head for it was another $136,150. There is a right to repair bill sitting in the legislature.
They make it up in repair parts. Last month a friend lost the fuel tank cap for his lawn tractor . JD wanted $ 38 for it. He found one made by a 3rd party for about $ 15 shipped to him. Just for a piece of plastic. They wanted about $ 60 for a 40 pound weight and the same for a 50 pound wheel weight.
** Like with printers and their ink / toner cartridges.
Long while back, Panasonic were selling portable CRT TVs in Australia. To avoid having to stock picture tubes for years, they priced the replacement at the same figure a new set sold for. Needless to say, no stock ever existed.
Nope. Look again at the surface of the brass gear.
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Sorry about the bad lighting and focus. Notice that the surface has raised "teeth" which cannot be pressed into a plastic gear. The brass hub is an insert into the molded part.
My guess(tm) would be glass reinforced nylon. The teeth are stronger than acetal (delrin) and seems like the right color. However, since the HP plastic shrank instead of enlarged when it absorbed moisture, my guess(tm) is that it's a mix of nylon and something else intended to compensate for expansion due to water absorption. I guess they added too much.
That would be a LaserJet 5MP.
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I would not consider the 5MP to be a printer worth fixing or keeping. I've had plenty of chronic problems with those and generally refused to fix them.
This is about 4 days collection of printers donated to the local recycler:
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Note that the pile is predominantly business class HP laser printers. Many were only a few years old. The pile of inkjet printers is elsewhere. Most printers were in very good condition and could easily be repaired and reused. Before the recycler signed contracts with various printer refurbishers, I could buy some of these printers quite cheaply, refurbish them, and sell them an acceptable profit. Most of these HP laser printers came from local medium size businesses and government offices. Both find it easier to obtain funding for capital equipment purchases, than for repairs and preventive maintenance. So, when a printer does something weird, instead of calling repair service, IT orders a new printer and recycles the old printer. In some companies, the rule is "nobody opens the machine" which saves money, but creates mountains of unnecessary eWaste.
Now that you point it out, I can just see the knurling on the brass insert.
Nylon is most likely. There may also have been a plasticiser of some kind, which evaporated. Molded plastic gears are an optical illusion anyway.
Yes. It's basically a backup printer these days. It cannot render and print modern complex documents.
I never had any problems with HP printers back in that day. They were built like tanks. More recently, endless trouble. As you mention later.
Yeah, I don't think companies bother to fix that size printer, if the printer cannot tell them what to clear or replace.
The big $30K printers big companies use are another matter. Those do get repaired.
I recalled what I had to fix on the Brother printer. I was getting an "Unable 32" error. This was in 2016. The fix was to install a bit of scotch tape on the now sticky rubber pad on the flapper sensor, to prevent it from sticking to a stop. Also took a bunch of deglazing and cleaning of rubber rollers and the like.
Also maxed the printer DRAM to 640 MBytes, because documents were getting bigger and more complex.
The real boat anchor bonanza was right after the subprime bust. Two cents on the dollar for top-of-the-line HP and Tektronix stuff, much of it with current cal stickers.
Figuring list price, my lab has a good $2M worth of stuff that I've paid less than $70k for, including a few much-appreciated donations early on. ;)
It's still pretty good if you know what you're buying.
Last week I repaired a really beautiful 100 kHz -- 1 GHz synthesizer (PTS 1000) by replacing its fried output stage with a Mini Circuits MMIC. Nice gizmo--its close-in phase noise leaves my HP 8640B in the dust.
Nope. Plasticizer is what is used in various compounds, including nylon, to make them soft and flexible. That's the last think I would want to see in a toothed gear. Plasticizer can be used to reduce friction in gears, but that's not needed in the HP8640B, where the gears are rarely rotated and then only by hand.
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Also, note that plasticizers are usually low volatility and act much like an oil. Were there to be a loss of plasticizer in the gears, there would also be a corresponding oily mess all over the mechanism or a puddle on the bottom cover. I've been there with flexible rubber parts. Silicone rubber keyboards are a good example of leaking plasticizer. Such keyboards are highly flexible and subject to finger pressure compression. After a few years, the plasticizer is literally squeezed out of the rubber and onto the gold PCB contacts and forming an insulating layer. That's when I have to open the TV remote, phone, calculator keyboard, or whatever and clean off the plasticizer.
Yep. In the days that the 5MP was popular (1995-?), computahs were seriously underpowered. Low end printers were cutting costs by having the rasterization and font rendering done in the computer instead of the printer. This was when the Postscript (everything done in the printer) vs Truetype (everything done in the computah) battle raged. What is probably happening is your modern computer is trying to print a complex document and expecting an equally modern printer. When faced with an antique printer, Windoze resorts to sending a bitmapped full page image of the page, rendered in the computers memory. This can be rather slow.
Trying to print an 8.5x11inch, 1200 dpi graphic, 16 bit gray scale, image is going to require quite a bit of computah RAM. 8.5x11 = 93.5 sq-in 1200x1200 pixels/sq-in = 1.44 Mpixels/sq-in 93.5 * 1.44M = 134,640,000 pixels per page Each pixel can have various shades of gray. The laser printers are either 8 or 16 bits/pixel (256 or 65,536) shades of gray. 134,640,000 pixels/page * 256 shades/pixel / 8 = 4.3 MBytes/page memory required in the printer. Your 5MP printer can probably handle that. However 16 bits gray scale per pixel requires: 134,640,000 pixels/page * 65,536 shades/pixel / 8 = 1.103*10^12 = 1.1 Terabytes of RAM. That's not going to happen on anything less than a laser printer with a built in hard disk drive for virtual storage. Whatever your printing has to be matched to the laser printers capabilities in terms of DPI (pixels/sq-in), page size (8.5x11in), and gray scale (8, 12, or
16 bit). If you complex document exceeds the printers capabilities, it simply won't print. Incidentally, I used to carry around a floppy/CD/flash drive with test prints to test what will break the printing system.
Hint: Reduce your expectations.
I beg to differ. I had a thriving side business repairing mostly HP laser printers between about 1984 (first HP LaserJet) to about
1997(?), when HP decided to start making "affordable" laser printers and switched from quality Canon engines to various Chinese sources.
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There were plenty of problems in the older printers to keep me busy and support my decadent and lavish lifestyle. I could get 1/2 million pages out of the older LJ3 and LJ4 printers, but it would eat fuser lamps, power supplies, fans, rubber rollers, and fuser assemblies to get there. In general, it was one rebuild every 75,000 to 100,000 pages printed.
After HP stopped making laser printers that would last a lifetime and switched to cheap junk, things were very different. The major change (for me) was that mechanical parts would break or wear out. The rattle produced by these printers was an ominous clue that they were loosely and sloppily designed and built. On some printers, disassembly was a major project. Along the way, HP produced some winners and some losers. The 5MP was one of the losers.
The big printers usually require a service contract which takes care of the preventive maintenance and parts availability problem. Much of the eWaste I've seen are such large printers, where the cost of the service contract exceeded the value of the printer, where it was more economical to buy a replacement than to continue fixing the old printer. Typical life cycle was about 5 years. There was also a reluctance by management to have employees work on even simple tasks, such as changing an air filter, emptying a toner waste bin, or minor cleaning. "Am I paying you to do this?" was a commonly heard question posed by management.
Common problem and the same problem as with HP. The foam pad used to dampen paddle switches, solenoids, and some moving parts decomposes (actually depolymerizes) and turns to sticky goo. Videos:
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Because of the heat, the tape should be Kapton tape, which doesn't "dry out" and fall off. However, I have a different method. Remove the sticky foam pad with alcohol, and replace it with either sticky tape backed felt pads, or a better grade of foam weather stripping. Make sure to get the same thickness as the original, and check the it will crush to the same amount as the original. One of these:
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Cleaning rubber rollers is a good idea, but don't use any solvent cleaner that doesn't replace the plasticizer in the rubber. Chlorinated hydrocarbon solvents will clean and deglaze the rubber rollers, but will also cause them to harden because the plasticizer is now gone. I use a noxious, toxic, and VoC banned concoction with a zylene base that works great, but stinks bad enough that I can only apply it outdoors. Maybe try a commercial product:
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I haven't tried these because I have a lifetime supply of the noxious stuff.
So much for the paperless office. See my calculations for how much RAM you need. Reminder: Laser printers have to have the entire page in memory before it can print. Inkjet printers only need to have a strip the width of the print head stored in memory in order to print.
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