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The prototype boards are back from OSHPark. Dang, they did a really nice job.

Not perfect, but the cosmetic errors are mine; I submitted the protos to about 10 online PCB joints to see who'd actually make them to my DRC spec, and a few bits like silkscreen holdoff didn't actually match everywhere. I can adjust that for a real run.

OSHPark was one of two places willing to do 6mil/6mil 2oz without several rounds of human intervention. The other is DirtyPCBs, and I can't wait to see what comes back from there. Suffice to say I hope they're serviceable (as they're about 1/10th the cost in batches of 100), but it's highly unlikely they'll be as nice as this.

Maybe I can push the rest of the BOM to be able to afford the difference, I really like these...

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Summary: Most 'new' HV121P01-100 SXGA+ screens for sale on ebay, AliExpress, etc, are neither genuine nor new.

Long version:

The HV121P01-100 is the screen every X60/61/62 ThinkPad modder wants. It's a reasonably high-resolution AFFS (IPS-like) screen originally offered as an option on the X60 tablet, and with a Daylight LED kit, it has excellent brightness and good (though not excellent) color accuracy. They're commonly available on eBay, Alibaba, DHgate, etc.

Except they're not.

A slightly later version of the screen, the HV121P01-101, was an option on the X61 tablet, but it had a fatal flaw. Unlike the earlier version, the -101 was bonded to a glass front-surface using a 'permanent' optical adhesive. This adhesive was not in fact very permanent. It flowed when it got warm, leaving bubbles behind the glass, and a sticky, impenetrable goo all over everything.

Ever get pine sap all over your hands and try to clean it off? Same thing. No really; the optical adhesive is a purified pine tar. Mmm, I do love that Christmas tree smell.

In any case, the HV121P01-101 turned out to be a warranty disaster and there were tons of these screens left over that no one could use.

A few modders got reasonably good at removing the front glass and adhesive through sheer force of will and infinite effort. This task is seriously involved. I tried it. I wasn't patient enough to get better than about a 50% success rate and it sure wasn't worth the time--- especially when you could just buy a -100 version of the screen without the problem.

These days, there are no more cheap -100 screens. Enter Chinese entrepreneurs and a large quantity of similar, unsold -101 screens.

Rather than spending hours of careful mechanical work removing the glass fronts and adhesive from the -101 screens, you can just dump the screens into a big vat of hot solvent. Of the solvents I've tried, xylene is cheap and works well. The solvent dissolves all the adhesive away over a few days, and the glass falls right off. No fuss!

This would be a brilliant solution except for one problem: it messes up the front polarizer film that's also bonded to the glass LCD matrix.

Good polarizers cost more to produce than the glass LCD matrix itself. BOE/Hydis used very nice polarizers on these screens. Removing the adhesive with heat/solvents damages this expensive polarizer.

The damage looks a little like a kind of 'old-timey picture-tube' filter:

The above screen was being fed vertical lines for whatever reason, it's the ring of discoloration around the edge I'm talking about. Below is a more subtly damaged screen that wasn't obvious until the backlight got replaced:

Depending on the exact process, the damage can be subtle or obvious. If the damage isn't 'too bad', the screen is just sold as is, and these screens are definitely out there in the wild (see above). I know a few people who didn't notice (or weren't bothered by it) until installing a brighter backlight that made it more obvious. That's how I got the pics (thanks guys!).

When the polarizer damage is too obvious, the screen rebuilder can strip off the damaged polarizer film and install a new one. Like I said, the best polarizers are really expensive, and I will say from personal experience that these rebuilders are, in general, not using the best polarizers.

Cheap polarizers make for poor contrast, and cause color shifts at an angle which kind-of negates the whole point of the fancy AFFS screen.

Honest resellers are up-front when the polarizer has been replaced, and the protective platic over the surface of the new polarizer will still be there when the screen arrives. Maybe you'll get lucky and it'll be a decent one. There's no way to tell ahead of time, but I personally won't bet on it.

The less honest resellers won't tell you, or will claim the screen is all new. Right now, this is also easy to spot!

BOE/Hydis original polarizers are always beveled at the corners:

Replacement polarizers are not:

I suppose dishonest rebuilders will eventually catch onto this trick and begin beveling their edges too, but so far they haven't.

Oh, and it can get worse.

Solvents will also destroy most of the other components in the screen. Some rebuilders carefully separate the parts and only dunk the glass matrices, limiting the damage to the bonded polarizer. Others just dunk the whole damned screen and let everything dissolve except for the frame, electronics and matrix. These screens then have to be built up entirely from spare parts.

In short, many of the HV121P01-100 screens you see for sale *don't have a single HV121P01-100 part in them*.

Those stickers that say 'HV121P01-100'? Fake, altered, or transferred from other screens. That closeup of 'HV121P01' stamped into the front frame? Note that it doesn't say '-100' or '-101'.


Do these rebuilt screens work? Yes. The problem is that many aren't going to be anywhere close to the original performance specs. The contrast will be lower, the brightness low/uneven, the colors poor or unstable, at least relative to the original screen, which was no performance monster to begin with.

Is that still worth ~ $100? You might say yes! The important thing is to know what you're getting and be able to make an informed decision. Otherwise you're playing a lottery and trusting the ticket-seller to tell you if you've won.

Of course, you might get lucky and get a real -100! If you do, let me know, I've not seen one in years, and I'd really like to know where I can get some.

So how do I find a real HV121P01-100?

No guarantees, but look for a few things.

  • Is the front 'glass' (acrylic on a real -100) still in place?
  • Is the original digitizer still on the back? It's the rust-and-green flexy circuit board that provides the pen input on the tablet screen.
  • Does the screen still have its tablet-mounting tabs?
  • Is any of the frame tape cut, or are the internal diffuser film clips mysteriously missing (probably because the replacement diffuser films don't actually fit properly)?
  • Is the listing using a stock pic (with a custom watermark) used by ten other resellers? Bad sign.

Not to pick on this specific seller (I doubt they know much about what they're selling), but here's a pic that hits almost all of the red flags all in one ad:

The digitizer is missing, the front acrylic is missing, the clips that hold the internal diffuser films in place are missing, the sealing tape along the bottom of the frame is cut, and the plastic cover with the 'HV121P01-100' sticker and serial number has obviously been transferred from another screen. Best of all, this is a stock pic, or rather, the exact pic is being used by 6 or 7 eBay sellers right now. They care so little about their listing, they're using a pic of a screen that's obviously been rebuilt from parts, not even trying to hide it, and the screen is listed as 'new'.


In any case, the best way to screen out sellers is probably just to contact the seller up front and ask specific questions. Most are just resellers, and have no idea what they're selling, but you can at least ask for pics of an actual screen for sale. Any evasion from the seller is a pretty good indication you should walk away.

xiphmont: (Default)

When I first offered LED conversion kits, I got the inverters I modded for free from forum members who sent their spares, supplemented by bulk lot buys of used boards from eBay. For the first 200 kits or so, I paid on average about $5 a board, which I then modded with the custom LED hardware.

The supply of X60 and X61 inverters is drying up, which is not to say they're no longer available, but they're now well into legacy pricing. Min price is about $20 apeice now.

Building complete inverters from scratch was probably always cost effective, but I just couldn't find the discontinued connectors I needed. I think I have those secured now, so I spent a few days of free time consing up a new inverter board design.

The prototype is off to OSHPark for fabbing! It's nearly the same schematic as the TLD3, but the layout is from-scratch to make it easier to assemble.


Nov. 29th, 2017 07:48 pm
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I'm about to ship my 250th ThinkPad LED backlight kit, all hand-assembled and soldered. I had no idea. I expected there to be demand for about ten. The kits are for models over ten years old... and demand is still increasing.

Not pictured: The stack of 30 different headless ThinkPads I use for kit testing.

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...so yeah, I'm apparently also in the custom Thinkpad LVDS cable business now. This one lets an X61/X62 motherboard use a 4:3 12.1" SXGA tablet screen. I'm still practicing, but I've found a source for 100 cables cheap...

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....w00t! Found the missing Thinkpad inverter stash! That should hold me through Christmas.

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Here's one of the little server mods I worked on over thanksgiving: flowGrab

flowGrab patches the server to also allow grabbing liquid flows (ie, non-source liquid blocks) with a bucket, and that includes buckets in dispensers. Non-source liquid in a bucket does not become a source when placed, it just flows away, but it does mean you don't need to sacrifice a source block to get a water bucket or a lava bucket.

This is no big deal with water, really. Water sources regenerate in Minecraft. Lava sources, however, do not regenerate. Use one up and it's gone.

I think you see where this is going.

It means you can grab as many lava buckets as you want out of a flowing lava stream, and use them to power furnaces.

It also means you can use a single lava source to power a machine like an autosmelter indefinitely.

WHOO SUSTAINABLE ENERGY! Your world's industrial base is no longer limited by however long it takes to completely mine out the Nether!

The patch applies to a clean decompile of MCP 9.40 updated to Minecraft 1.12.2 in the usual manner.


Nov. 19th, 2017 07:13 am
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A cold, wet dawn outside the workshop in NH today, sleet hitting the windows...

It's nice and snug inside, though. Time to get some French Toast on.


Nov. 15th, 2017 11:04 am
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I haven't forgotten about Workbenchapalooza2017, it's just that work got busy and ate all my weekends the past couple of months. I've been stealing a few hours here and there.

I finally completed initial assembly of the prototype/archetype workbench I'll be using in the workshop. Design criteria:

  1. Inexpensive materials
  2. No fussy joints; it's all flat-stock glue & screw.
  3. Stong and rigid; top section is a 7.5"-thick box-beam that will take a sledgehammer blow.
  4. Easily replaceable top surface; it's just a trimmed sheet of 3/4" particle board with some optional edging.
  5. Storage; "I could count myself the king of infinite space were it not that I needed more flat surfaces."
  6. Drawers are just an optional insert.
  7. Disassemblable; it tears down into several flat panels.

I have dubbed the design 'Bork', which is either short for Borkwench, or alternatively in honor of Ikea. Your pick.

The assembly fit is a little subpar as it was the working development prototype, but I think it's also good enough to be the first production unit. Now for a bunch more.

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...only 1000 left to bin on this reel....

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View from the [soon to be] woodshop this morning. Somehow I missed it snowing overnight.

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Hmmm... George is squinting in each picture. I wonder if he needs glasses already.

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Ovenbirds are my favorite of the warblers, so I was heartbroken earlier today when I heard a 'THUNK' against the window behind me, and looked outside to see an ovenbird stretched out on the ground on its back, not moving.

I went outside to check it, and it was still breathing erratically. After about ten minutes of twitching, it finally righted itself and looked around briefly, but was still too stunned to do anything. It did not object to me being next to it, so I figured I'd sit and guard it until it either regained its senses or finally succumbed. After another fifteen minutes or so, it clumsily staggered into a bush, where it hunkered down and curled up. This was the longest recovery I'd witnessed for a stunned songbird, and I didn't expect it to make it.

In late afternoon, about eight hours later, I checked it again and it had not moved. Breathing, yes, but still apparently 'asleep'. Cam agreed this did not bode well.

I wandered off to shoot a few targets (setting up a new bow! yay!) and once the sun was well behind the trees, was wheeling the portable target block back to the garage. I passed the bush where the ovenbird was holed up, and it popped out, looked startled, and flew off. It was clumsy getting into the air, but it managed. Perhaps a recent fledge?

Good luck little birb.

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Given their long-distance migrations to southern climates, I always thought of monarch butterflies as exotic creatures that bred elsewhere and only visited when passing through. Of course, that's not true. Still, most of my formative exposure to monarchs led me to believe that, around here, they only thrived in elementary school classroom monarch hatchery kits.

We have a decent amount of milkweed growing around the house in NH. George and Cam spotted quite a few monarch caterpillars a few weeks back, and we'd been watching the perfect green chrysalises. When we got in Friday, George excitedly pointed out a 'newborn monarch" pumping its wings open!

Another hatched a little later, and a few more of the chrysalises are starting to darken. So perfect and shiny...

...and the autofocus on my Nikon seems to be off... But just look at that face!

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Flashback: T-2 days to eclipse.

I looked around the workshop and noticed I have boxes of left over optics that didn't work out in various projects over the years, including some nice big achromats I grabbed from Anchor and Surplus Shed a good ten years ago.

And then, later in the day, all the empty shipping tubes from McMaster in the garage caught my eye... Read more... )

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after more practice stick-welding aluminumium, I can proudly report... I still pretty much suck at it. Getting better at maintaining arc at least.

Anyone got tips for fillets on inside corners? With Al, the arc always snaps to one side or the other, and trying to drag across the corner either sticks the rod (because of waaay fast consumption and a tendency to ball up) or blows out the arc.

(Remember I'm working on sheet and, at thickest, 1/8" plate--- I can't just crank up the amps and linger.)

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The band saw's intended function is cutting multi-inch-thick metal plate. More often, though, it's really the only tool I have that can open those freaking clamshell packages without a good chance of injury.

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Finally, assembly... and confirmation of non-embarrassing results.

Read more... )

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There's one thing left to worry about. The left hand focus knobs are, for whatever reason, set in toward the centerline of the focus block about a quarter of an inch compared to the right. The coarse knob almost-- but won't quite-- clear the SZH's uniquely wide microscope body.

If only I had some roughly 80-mil plate with which to fashion some spacers! Oh right...

(/me fishes spacer pieces from previous adapter attempt out of the scrap aluminum pile)

OK! First I need a ring spacer to set the coarse focus knob further away from the centerline.

Done! Now, the fine focus knob needs to be set away as well.

I considered making a shaft spacer, but it will weaken the overall assembly. Instead, I heated the brass inset in the fine focus knob until the ABS softened, then pushed it in 80 mil. I did use a guide to make sure it pushed in straight and flat-- no wobbling allowed.

The fine focus also has a spring-loaded friction mechanism to add a little resistance to it drifting. One side is built into the knob, which I just moved out 80-mil. So I need an 80-mil spacer to take up the slack.

Don't worry, the hammer in the background is a specially designed precision optics hammer.

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That's more like it.

And a Micromill ain't no toy.


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