Re: Miraculous button makes things work again.

Two days after the warranty expires, of course.

Additionaly, if you have 'normal' hearing loss, those piezo buzzers cannot be heard without hearing aids. I don't wear hearing aids to bed -- so smoke and carbon monoxide alarms will never awaken me. We had a CO 'incident' several years ago, and my wife heard the alarm. Not me. I can be standing in front of the microwave and I won't know my coffee is hot until the "END" lights up.

Microwaves usually have a fan that makes lots of low frequency noise. They don't really need a buzzer.

Piezos are cheap. For a few cents more they could use a speaker and give users a choice of sounds.

Several ways to determine when to self-destruct:

1. Warranty timer. The timer records how many elapsed days between when power was first applied and the current date. When the timer shows 110% of the warranty period, it declares a fault or failure. The extra 10% is to deal with errors in the timer.
2. Predicted use. The "chip" in many inkjet printer cartridges is a good example. The manufacturer decrees that the inkjet cartridge should last 1,000 pages. When the chip counts 1,001 printed pages, it ceases printing and produces a difficult to decode error message. It's much the same with laser toner carts and drums. With older iPhone batteries, the clock was slowed down to simulate the effects of an aging battery.
3. Predictive QA. Estimating the length of time a product and its individual components might last is calculated by the QA department. If a component survives longer than the approved warranty period, the component is subjected to a "cost reduction", which reduces the component lifetime, quality and cost. If this ritual is performed often enough, all the components in the product will fail almost simultaneously.

The actual length of time or number of operations before self-destruction is set by the manufactory marketing department.

Any companies we might have heard of been found out doing this, Jeff?

Don't buy HP printers. They are in the theft business.

Brother is a much better deal, both laser and inkjet.

Yes. I've had the displeasure of attending a few design reviews, which were mostly cost reduction exercises. Only suggestions which lowered costs were considered acceptable. Please don't be overly judgmental. Missing a cost target could result in the loss of a bid, having a volume buyer switch to another vendor, or a blood red loss appearing on the bottom line of the annual report.

I assume you want me to provide a list of companies who had implement cost reductions based on QA statistics. Sorry, but I'm not thrilled with idea of disclosing the names my clients and their activities on Usenet.

Most of the company I've worked for have done something similar. Substituting inferior parts doesn't require QA statistics. Some companies will gladly substitute cheaper parts if that improve the bottom line. QA will usually fight such downgrades if only for show. They know their jobs might be at risk without the cost cutting.

After such downgrades were implemented, they sometimes hire me as a consultant to "fix the problems but don't change anything". Sometimes I give up in disgust or suggest they replace the inferior parts with the original parts. What they really want me to do is give up. Then, management declares that because I couldn't fix the problems, the junk parts must be the best that can be found for the intended purpose.

I fix a few home and small biz laser printers. The low end inkjets go directly to the recycler. My favorite brands are HP and Brother. Home users tend to keep their HP laser printers far longer than their computers which translates into HP repairs instead of replacements. A few business users recycle their HP printers immediately after they run out of toner.

I like HP because some (not all) of their printers are good quality. OEM and aftermarket parts are erratically available. Brother laser printers also have their problems. However, I can buy 2.5 Brother printers for the price of an equivalent HP printer. Both companies have baked in design defects which they seem to be ignoring. Looking around my house, I have 2 HP color laserjet printers and 3 Brother laserprinters.

HP sells printers cheap with half-filled cartriges, and charges as much as a new printer for a new set, which don't last long. If their printers came with full cartriges, people would throw away the printer when it ran out of toner.

Our Brother B-size inkjet printer/copier/scanner is great, and ink refills are cheap. We do B-size schematics. They have a giant black cartrige too; we mostly use black.

What are the Brother design defects?

Wasn't it HP that was spying on customers by some ingenious yellow pixel scheme? Then made some excuse about catching forgers or some such claim.

What does B-size mean? Is it bigger than 8 1/2 x 14?

Brother MFC-L2740DW printer:

If the owner pulls out the paper tray while it's printing, the printer does not stop printing. Instead, it cracks the tiny feed gear. I have some photos I took of the damage and subsequent repair, but I can't find them right now.

In the front center of the paper tray, there is a translucent roller that is part of the paper feed mechanism. Static electricity causes this roller to be packed with paper dust and eventually stop turning, causing a paper jam or other paper feed failure. The paper dust hides UNDER the translucent roller and is easily cleaned out if you can figure out how it's done. I can take a few photos showing how if you want them.

Near the translucent roller in the paper tray is a friction pap. The pad and the feed roller above its position in the paper tray tend to develop a smooth polish. The loss of friction causes feed failures. Brother's idea of repair parts are toner carts and drums:

The paper stop near the back of the paper tray is fragile. Push too hard inserting a stack of paper and it will break. This should work as a replacement:

The main PCB in the printer uses a super capacitor instead of the usual lithium coin cell to provide power to the circuitry that stores the printer settings. When it fails, printer won't turn on. Replacing the super capacitor involves disassembly and soldering. YouTube video on how to replace the super cap:

That should be enough for now...

Jeff,

Very interesting in general, and I just bought a Brother MFC-L8905CDW. Have you encountered any of those yet?

What the above replaced was an ancient Brother MFC-9840CDW, and I did have and repair many problems, and got 15 years out of it.

Thanks,

Joe

I retired from the daily grind just after the CZU fire and Covid. I currently don't see many repairs on larger and heavier printers because I would need to carry the printers up and down 50 stairs to work on them. I also don't have the necessary bench space available. My current customers are mostly home users who normally don't need or purchase big and heavy business class printers.

I haven't worked on any MFC-L8905CDW printers but have recently cleaned a similar model after an aftermarket toner cartridge dumped toner everywhere. I didn't see anything unusual when I tested it.

The old MFC-9840CDW (discontinued) was not a good printer.

Try:

I have a couple of Brother MFC-6490CW B-size all-in-ones that I just love. Excellent print quality with cheap, chip-free ink cartridges, good scanning, no worries.

Good Medicine!

Cheers

Phil Hobbs

On Sat, 1 Feb 2025 18:24:20 -0000 (UTC), Phil Hobbs snipped-for-privacy@electrooptical.net wrote: (chomp)

Also, not having to deal with refill protection chips on the toner or ink carts is a big savings. The Brother MFC-L2740DW laser printer I previously mentioned is the last of the Brother home or small office printers which do not require a toner cartridge with a chip.

This photo is from 2019 at the local recycler:

Thanks. What does "good medicine" mean?

I have days like that too. As long as it's not weeks, I'm not too worried.

here's an old series of articles by the kind folk at EFF describing the issue.