Rick's b.log - entry 2022/05/01

Vide grenier

Unfortunately in France holiday days happen on the day of the holiday. There is no Bank Holiday Monday. I'd have a day off if this day was in the week, but since it's a Sunday, too bad.

I got up bright and early, half six. Fed kitty, downed a tea, read stuff on-line and somehow stumbled across a web series on YouTube called "Crown Lake". I watched some of that. Plus a slow-mo guy video about a complex robotic system for capturing slow motion special effects.
As it was getting to be 9am, I decided I'd look up to see when the vide grenier started.
I mistyped "Teil" and Google thought I was talking about Teillay, which was apparently also having a vide grenier today.
A big one.

Ten minutes later, in the car.

I barely drove ten metres when the brake warning light came on indicating that the ABS has shut itself down. My guess is that it is detecting 'n' wheels are turning, where 'n' is a number less than four. Because of this, the ABS is obliged to shut itself down as it cannot do its mojo if it can't tell at any moment in time the rotational speeds of all four wheels.
Which sounds to me like a sensor failure. Or dirt. Or a broken cable. Whatever.

I did a fairly rapid stop at the end of the driveway, and a couple more on the back roads. I had to press the brake a little harder than normal as it's fully pneumatic now rather than computer assisted, but asides from that braking was fine. As I said last time, I tend to drive cautiously anyway. All too aware that I'm basically in a moving yoghurt pot. ☺

With Google to tell me the way, I made it there in... actually I have no idea, I didn't bother looking. About 30-40 minutes. But through lovely scenery.

Teillay's vide grenier sign.

Well, I made it. The first vide grenier since the palindromic date of 2020/02/02. Now, I'm not going to be going to many of them. There's the price of fuel, and also that it was more a mom thing than a me thing. Plus, ever since the likes of eBay and Le Bon Coin became popular, the stuff at vide greniers has nosedived in usefulness. For example, in a large exposition with a few hundred vendors, I saw only one console (a PS3) and no computer equipment (laptops, monitors, or PC boxen) at all. I'd imagine all that stuff is now on-line.

But it was nice to walk around and look at stuff, even if I was practically the only person wearing a face mask (no, people, Covid hasn't gone away!).

At the vide grenier.

I parked in an lotissement, a housing development. Then had about three quarters of a kilometre to walk. Just as well I packed a Mars, wasn't it?

There... wasn't anything of interest to be honest. After doing it all, I walked back to where I saw a little laser printer. Not something I'd normally be interested in (it wasn't WiFi or anything) but going home empty handed didn't feel right. A big vide grenier, loads of people, first one in two years and nothing?

I'll talk about this next...

I was home for noon.

LaserJet Pro M15a

So I stroll up and offer her twelve euros. She looks at me and laughs and says go away. She isn't going to sell that for two euros.
Bloody French...
No, not two, twelve, ten plus two. It's all I have on me.

I don't push things like asking to look at the printer because I want her to come up with a reply while feeling a little sheepish. Which she does. A long sigh, followed by "yeah, okay".

I walk away with two boxes. Which could be boxes of pebbles for all I know. She did tell the guy before that the printer works.

Truth be told, it was total balls. I raided my piggy bank, this piggy bank...

My piggy bank.

It's a confidence game. A bit like poker but without the ridiculous stakes. Was I telling the truth when I said it was all I had? Was she telling the truth when she said it worked?

The device itself is an HP LaserJet Pro M15a, claiming something on the box like "the world's smallest laser printer".
With 8MB of memory onboard and a print engine capable of 600×600 dpi, it seems like a reasonable enough device, if a little pricey for what you get (it's listed as €230 on Amazon).

Twelve euros of "stuff".

Upon looking in the first box, I saw the toner drum/cartridge had pretty much just been thrown in. Which was... odd.

The drum and toner cartridge.

There was indeed a printer in the box...

A printer in the box.

But all became clear when I looked inside.

Nothing inside!

That's... actually a bit crappy. In order to boost how much she was going to ask, she took the cartridge out of the printer to sell separately. Plus, doing it like that, exposing it to light and the risk of scratches.
Upon seeing that, the miniscule amount of guilt I had over blatant lying evaporated.

I put the drum into the printer and powered up. It started up. Gears turned, clanked, rumbled. Then a solitary green light was looking at me.

The printer has, literally, two controls. The power button, and... another. Resume? Abort? Don't panic?

Now something you can generally rely upon with most laser printers of this nature is that if you hold down the button that is not the power button for several seconds, one of the indicators will start blinking. Let go of the button and some sort of status page will be printed.

It was.

Badly.

A bad test print.

The text was there, but rather smudged, and I could practically brush it away with my finger.
I did another test print. Not expecting a different result, but instead to feel the paper as it came out.

Warm.

So the fuser is operating, sort of.
Now, fusers tend to be either metal heater elements or bloody great halogen bulbs.

How a laser printer works is a piece of paper enters. It passes through the gap between the transfer roller and the drum. Now, the drum is positively charged in some method, sometimes with a corona wire. This dumps static electricity onto the drum surface. A bright beam of light scans across the drum from one side to the other, repeatedly, with it flashing on and off according to what is to be printed. In this respect, it isn't that unlike a monochrome television.
When the beam of light hits the drum, it causes the charge to reverse. These areas of reversed charge will attract the positively charged toner particles causing them to stick to the drum.
The piece of paper, as it enters, is also brought up to a positive charge, often with the same corona wire. This causes the negatively charged toner particles to stick to the positively charged paper. The transfer roller just presses the paper against the drum for good contact. Following this, a rubber scraper cleans the drum surface returning leftover toner back into the cartridge, and also dissipating any charge ready for the next time around.
The next step is to pass the paper through the fuser unit. This heats up to around 200 degrees. Toner is actually mostly made of very finely ground coloured plastic. So what happens in the fuser is the paper passes between a hot roller and a teflon coated roller. This causes the toner on the paper to melt and bold with the fibres of the paper, which means the print isn't affected by water or alcohol or anything like that. The paper, on the other hand...

You might recognise the process, it's very similar to how a traditional photocopier works.

Now, this printer is technically faulty. It's no use having a printer that can't fuse the toner to the page. That's like a bicycle with no tyres on the wheels.

Any ordinary person would, at this point, think "that lying b**ch" and toss the thing in the bin.

I just say "Oh, yes!" and reach for my screwdriver. Even if I have no idea what to do with this device (no WiFi and probably speaks some weirdo version of PCL), I have too many printer fixes under my belt to not attempt a repair.
Plus, twelve euros of fun. This bit of unexpected problem solving can keep the grey matter exercised.

After a bit of fiddling, it was possible to pull out the viscera.

The insides on the outside.

Here's the tiny controller board. The SoC is a 88PAPL01 which is made by Marvell and... that's all I have been able to discover. The little chip to the left is a 25Q64JV SPI Flash, offering 64 megabit or 8 megabytes.
The little chip above (54335A) is a DC-DC voltage convertor.
The big Zentel chip? That'll be the 8MB RAM.
I notice there's a two pin DEBUG port (left of the RAM). Likely to be ground and serial data.

The brains of the operation.

The entire back has a massive circuit board that is mostly power supply stuff. But there's an RK2?9867 (RockChip) device.

The microcontroller on the rear board.

At the other side, in order to keep the size down, the laser has an interesting arrangement.

The laser in laserjet.

Lower left, a laser LED. This shines on to a four sided spinning mirror which directs the beam upwards. The beam passes through the bow-shaped lens which stretches it out to fill the width of the page, before hitting the 45 degree mirror at the top that directs the beam towards the drum.

Finally, after much stripping down, the problem makes itself known.

The problem.

But, we aren't there yet. The gear wheels won't turn backwards, so the big springs on either side must be unhooked in order to slacken the teflon roller enough to allow the piece of paper to be pulled out.

This, of course, is the downside of "smallest laser printer ever". A normal printer can be opened up to access the bits inside in case of a printer jam. But this thing? Needed some screwdriver action to get enough of it apart to find and fix the problem.
Though, truth be told, I might not have needed to take it entirely out of its casing to get to this part. But it was perhaps better that way in case of a dropped screw or whatnot. It wasn't too hard to get at the part in question, just really really fiddly.

Whut?!?

The piece of paper in question is a thin piece of lined notepaper, onto which appears to have been printed something to do with cardial (heart) information in English, translated into Italian, looking like miniatures of Powerpoint slides. Which is, let's face it, was absolutely going to be our first guess, right?

What was printed.

Putting the device back together was simple enugh. The subsequent test print was perfectly fine. Clear, sharp, no smudges, ghosts, or other patterns.

A good test print.

The most amusing thing here, I guess, is the event log. It looks like things went wrong at around about page 896/897. There was a lot of toner fused onto the piece of paper stuck inside, so it looks like another fifty pages were put through, but by now the printing would be failing due to insufficient heat transfer. Plus, the more toner stuck to the paper inside, the less effectively anything will work.

Until page 946. That's my first (bad) test print. And an error code as I caught it coming out the top, with the door open.
The error 52.xxxx is a laser startup error. Might have been when I had the cover off to take the photo. I wanted a photo of the mirror spinning, but it goes crazy-fast.

Whatever. A two hundred euro(ish) printer with a firmware dating 2019/07/25. I remember that day. My last day of work before my summer holiday. The last day mom ever picked me up. And Johnson became PM.
An expensive reasonably modern (if somewhat underwhelming) printer that crapped out before it's first proper (non-setup) toner cartridge had run out, all because some twit decided to shove in lightweight note paper instead of a piece of regular A4.

After my few test prints, it has now printed 950 pages, total, in its entire life.

It's nearly 5pm and really quite hot (it reached 20°C). So... I think I'll upload this and go set up the hammock for a while.
Yeah, that sounds like a plan.

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David Pilling, 1st May 2022, 18:28

Good find. Satisfying fix.    Years back I chickened out of fitting a replacement part to my Canon LBP8 (Laser Direct) - too complicated. Watched field service engineer fit the part - still looked too complicated.

J.G.Harston, 1st May 2022, 21:38

I've got a bin-scavenged laser printer, the only fault is a thumbprint-sized smudge every two inches or so down the page. It's clearly something similar to this, my guess is a bit of a sticky label stuck on a roller somewhere. Promble is, I don't have the space to spread out to dismantle it sufficiently to find the problem. When the weather gets better I may take it out onto the garden bench.

Steve Drain, 1st May 2022, 21:40

Back in 1988 I bought a QUME CrystalPRINT printer to go with my A440. This was a horrendous expense but a great compact printer. It had no lasers, but a strip of LEDs.    I kept that going with several repairs for another 10 years of quite intensive use. I eventually had to give it up only because replacement drums became unobtainable.

Rick, 1st May 2022, 22:19

Oops, I forgot the main board photo! Fixed.

David Boddie, 1st May 2022, 22:45

Nice fix! At least you didn't have to go all Michael Bolton on this one...

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