Ask HN: Help me restore the LCD displays on classic samplers so I can use them
I have gotten hold of a few classic Akai samplers from the 90ish.
Sadly, the lcd screens are either not working, or impossible to read, or faintly visible.
This is a common problem think with a lot of electrics from the era.
I will focus on the Akai S3000XL.
Its near mint. Everything clean, wonderful buttons, mint condition inside.
Turns on spins the cdrom drive, checks the floppy.
but the screen while illuminated is entirely blank.
I can turn it on and off, and I can adjust the contract.
All of which I have done without any improvement.
Now I can easily fix this buying a replacement here
https://www.mpcstuff.com/lcd-screen-for-akai-mpc-3000-s3000xl-mpc-60ii-mpc60-led-upgrade/
But its $223USD plus shipping and customs.
I cant afford that for one sampler and no way I can afford it for several.
Here I need your help.
I am a software guy, not knowledgeable on hardware.
Displays in this form factor can be had for cheap.
but of course it won’t work (I believe) with the connections,
I need “hardware” that I can plug into the connectors for the display on the sampler,
and connect it to a cheap display that can be had cheap now.
I sort of wonder if a Pi could be used as the. Bridge hardware.
I would be quite willing to have connects hanging out of the sampler as long as I could have screen that I could look at. Then I could use ut (ugly ugly ugly and not ideal).
How do these things work?
Are the original displays programmed in a “do this with pixel ,3,3” that is uniform at some level? Or are the displays more like a terminal? Is there a way to unify these things?
54 comments
[ 3.0 ms ] story [ 123 ms ] threadThis interfaces with the CPU's bus and produces very low-level clock & data signals to the LCD panel (CL1/CL2/FLM/MB/D1) - basically a stream of pixels along with synchronization pulses.
Nowadays most "graphic LCD" modules will incorporate a similar chip on-board, so that they can present a simple 8-bit parallel interface.
Capturing + translating the signal would be tricky - it's not _terribly_ fast (240x64x60Hz) but there's no flow-control or error-correction, basically low-resolution video capture
Give yourself time to learn electronics and how to repair instruments. Maybe it will be your new hobby and you will buy an oscilloscope. Maybe it won't. Good luck.
As noted, the expensive MPC60/3k replacements are just generic T6963C / RA6963 displays with the circuit bypassed (since sampler has the LC7981) and the correct pitch ribbon cable soldered.
Honestly, I'd probably just pay the premium and buy a kit if I did it today.
I did this during COVID lockdown when my hobby/project time was valued differently.
if you are concerned about $200 for a replacement kit you should probably sell them to someone else
1: https://web.archive.org/web/20150406014725/http://www.soundo...
[0] https://reverb.com/item/74573558-akai-s3000-xl
But that doesn't mean anything about the cost to repair, upgrade, or in the case of LCD replacement, modernize. The memory, flash, effects, and expansion cards are highly sought after, and you're competing with bigger budget established producers.
My point was that it reasonable to be reluctant to spend $200 to $250 to replace a small component of a device that is only worth $300.
This was in response to someone who claimed the OP should just sell it if he didn't want to spend $200 to fix it - because it originally cost $3000-$5000.
Yes, the base unit themselves might be cheap. But once you're looking at enthusiast-produced LCD replacements or optionally-purchased-in-the-90s expansion cards, having sticker shock is expected.
LCD parts are cheap if you want to put the domain engineering work and solve engineering challenges yourself. They are expensive if you're one-stop buying a targeted kit and just trying to max out your upgrades.
An HN poster might be willing to put in significantly more time head-desking and soldering to save $200. A producer buying a vintage Akai is not necessarily looking for an EE project.
To that producer, the functionally upgraded unit is "worth" a lot more than $300 since they're selling the products of it.
I agree that using original MSRP is absurd though. The S3000XL is a later model from them and can be found for cheap all over the place - they made a bunch of them.
S1100 series are sought after but those are usually close to $1k in excellent condition, and getting maxed out memory could cost $3-400.
S950 sell for over $1k usually as well.
And I don't know how I can be clearer than in the comment you are replying to: "My point was that it reasonable to be reluctant to spend $200 to $250 to replace a small component of a device that is only worth $300."
Which part of this sentence is unclear?
Your Porshe analogy is not appropriate. If a Porsche with a working gearbox is worth 35k, then yes, I'd be reluctant to spend 30k on a gearbox alone.
The grandparent’s point was that these things retailed for lots of money when new, so they make the claim that the relatively small $250 LCD repair is reasonable.
I don’t agree that this is a logical conclusion to draw - anchoring on a 30 year old sale price seems self-evidently invalid.
All I was pointing out is these things did in fact retail for $X,000, regardless of the current value.
There’s videos on YouTube with guides on using old iPhone screens to illuminate the old screens.
Can you tell if the pixels are correct and there’s just no light? If so, the LED backlight replacements mentioned would be the answer.
As I understand it, you just want to be able to control the device. Maybe keep the display as is, intercept the signals and forward them (wirelessly) to an external device for display?
You are correct. Though I am fine with it being wired. The Pi is good since I already own it. Heck, I can use a laptop for it, since I have a couple.
Actually that would be cool since if somehow I could wire it up then I already have a big screen to render things on ,.
That would mean I needed a way to get the cable / signals to the PC. Sine I have an old laptop I might get to run Linux it would have serial and parallel ports if that would make it easier,.
Or some gizmo that takes the wires from the Akai sampler and makes USB
Check eBay - I got mine for much cheaper than MPC Stuff from a UK seller
Jazzcat + Ebay sell expensive replacements, but they are actually just cheap LCD displays with the driver circuit bypassed (since the MPC/sampler has a discreet IC) and an epoxy blob to prevent copycat work.
I need to dig up the wiring diagram, but the gist was from an EEVBlog forum post and only took an evening to reverse engineer.
Then I heard from somewhere else that it's actually not true. There's a very common (most common?) type of capacitor that very slowly loses capacitance over time. But heating it up and cooling it down resets it so it's like new.
Either way, I really wonder how much e-waste out there is just due to old solder/capacitors that could have been easily repaired.
Actually, both are true!
The solder stuff ("Soldergate") was around the time when the EU RoHS directive came into force - around the late '00s IIRC. The most affected product was everything with a NVIDIA GPU [1] (including Apple, who then cut all ties with NVIDIA as a result), but AMD (or rather, back then ATI) was also hit as they manufactured the Xbox 360 GPU with its RRoD ("red ring of death") issue [2]. In all cases, the issue at the core was an untested combination of no-lead solder elements that didn't handle frequent high-amplitude heat/cool cycles all too well, and a common fix was indeed to bake the PCBs in an oven to achieve all solder balls getting equally hot, basically low-temperature DIY annealing.
The capacitor issue cropped up around the same time - an engineer had stolen the electrolyte formulation from his prior employer, mis-copied it and eventually through his new team defecting (and stealing the broken formulation...) it spread around the industry [3]. All electrolytic caps age (particularly if used at the upper end of their rated temperature scale!), but the ones made with the broken formulation age muuuuuuch faster. Note that there is no fix for a dried-out elcap, the only fix is replacing it and in the case of an exploded one, cleaning the entire board of spilled electrolyte.
The problem is in both cases, these issues are hard to troubleshoot without expert knowledge and tools, in-place measurement can be very tricky (say because a capacitor is in parallel with an IC or resistor), and even if you have both the knowledge and the tools, it can be a wild wild goose chase to repair a broken Thing as for 99.99999% of equipment (outside of cameras and some phone models where for whatever reason everyone and their dog leaks component-level repair guides?!) you will not find information regarding component values, small SMD parts have no distinguishable parts marking at all any more, and manufacturers keep adjusting PCBs between revisions (to keep up with compliance requirements, fixing hardware errata or just because a part becomes unavailable) without that being apparent to the customers.
We desperately need laws specifying that all PCB design files have to be submitted to the government and that they be released to the general public after the manufacturer ceases support.
[1] https://www.overclock.net/threads/inq-nvidia-gpu-defects-exp...
[2] https://de.ifixit.com/Device/Xbox_360
[3] https://en.wikipedia.org/wiki/Capacitor_plague
Aaaaand that's my daily reminder to read to the end of a given post before reaching for the vote buttons.
To extend on my reasoning: it seems like the camera and phone industry is still perfectly thriving despite very precise diagrams right down to circuit designs and component specifications being accessible via nothing more than a Google search for "sony <model> service manual level 3". There is a healthy ecosystem of devices and manufacturers on one side, and officially licensed as well as unlicensed repair shops on the other side, and there are many resellers for original spare parts as well that allow both larger operators and adventurous tinkerers to repair their devices on their own if they want.
Unfortunately, this cannot be said about a lot of other electronics branches where a lot of Things eventually become dead paper weights due to DRM, bespoke critical parts failing without spare part supply chains and/or information how things should work (say, test point voltages, signal patterns, ramp-up periods) or simply because the manufacturer vanishes off the face of the earth, forcing owners of such devices (assuming they still work after the manufacturer ceased paying server bills) to decide between doing what is right and discarding of stuff that poses a threat to other netizens or to keep their stuff running and have it hacked sooner than later.
Since the market has clearly failed to provide products that are built to last, the e-waste amount is clearly unsustainable and the electronics markets of Shenzhen with the wizards there being able to do virtually everything one desires cannot be replicated elsewhere, I propose strict governmental regulation.
Yes, they were professional equipment. Yes some have unique workflows or analog stages that make them interesting.
That said, having fixed a lot of audio equipment in my life, there are a lot of off-the shelf parts for things and a lot of close equivalents.
For instance, the display in the Roland XP10 keyboard uses a pretty standard, segmented LCD controller. All I had to do was figure out how to connect the ribbon cable to some specific pins on the controller, set a color (because the controller I added was now backlit, which is an upgrade).
And then you discover that the plastic on the keys has some deformation over the course of 40 years, so everything is sticky and you need to get a dremal and rework every key.
In any case, I found that with these kinds of long term projects, your are often better off "going back to school":
get an arduino and a couple of different controllers that seem similar to the one in the devices you're interested in,
build some displays that are similar in topology to those displays
find the schematics for devices-of-interest
build some similar displays until you understand how the displays are working in those devices.
After you've done a little work like that, you can start to look at schematics and datasheets and figure out what kinds of parts that you're needing to implement the display.
IME, that's a couple of hours a week for a couple of months, but after that you're in a place where you can do what you'd like as far as avoiding $250 drop-in replacements.
Unfortunately, with your s3000, it may be the case that there is a different issue- the memory is non-functional (about 20 years ago, I had an s2000 go wonky cause the diodes in the cheap simm I put in it blew up).
Anyhow, if you're a software guy, then you know how to learn stuff- you're gonna have to give yourself a little hardware school before you can do what you'd like to do.
I found it fun, but in retrospect my time would have maybe been better spent making music or making money so I could afford time to make music.
Get a copy of RX950 (https://www.inphonik.com/products/rx950-classic-ad-da-conver...) and Decimort 2 (https://d16.pl/decimort2) or whatever the newest equivalent is to fill you Akai sampler sound needs. If you really want to twist knobs, I have a Novation 49SLMkIII (https://us.novationmusic.com/sl) with 8 encoders mapped to all kinds of things in my default Ableton template. It's so friggen amazing (parts of the living in the future are really cool). I only wish there was a place for music collaboration in this future reality (and not just 'I can't be bothered to read the manual/learn music technique be my interactive manual' or horrible toxic negativity (looking at you KVR and GS)).
Edit: I prefer other filters than rx950 that have more flexibility only recommending it if you need a specific Akai replacement. BTW it's sometimes the included freebie at PluginBoutique. Jason Herd uses it to good use in this walkthrough https://faderpro.com/programs/making-minimal-tech-garage.
* Find an equivalent LCD matrix. This is probably not that hard. This display seems like a generic part and LCD matrix displays haven't changed much over time.
* Fix the backlight. That would mean taking the display apart and probably resoldering some LEDs, assuming that it's the LEDs and not, say, a capacitor that is causing the brightness to diminish.
Going beyond these options, you'd be getting into decoding the commands to the LCD driver chip and displaying those somehow, which will be custom hardware development.
[1] https://www.asari.jp/diary/archives/007355.html
In rough order of difficulty/complexity:
Simply remove the module, wipe down the connections with alcohol, reassemble. If there's a 'zebra strip', gently peel it off, clean both ends, reassemble. If you see improvement, repeat with care until all segments are alive again.
Replace the backlight. Depends on the exact module, but sometimes they're just simple LEDs that can be replaced.
Ensure the polarizing filters still work. You'll need to research LCD polarizing, it's more complicated than I care to explain in a HN comment. They can degrade and sometimes need replacing.
Beyond this, you're looking at an electrical fault or the display is just dead. You'd have to start probing the display driver to examine the signals. A good starting place is to replace all the electrolytic capacitors.
Barring that, you likely have a bad display module. Sometimes you can test them by connecting some pins to ground and just touching other pins with your finger. The static electricity in your body can be enough to flip segments on
You can duplicate that effort. You can buy one, figure out what display they are using, and order more. You can order the bezel and duplicate it on a laser cutter. Is it worth it?
Also these displays are still available, but usually come with driver ic’s blobbed on. You can probably just bypass the blob or even mount the lcd module on the old board. (They usually just are mechanically attached ). Buy a couple of cheap character displays of the same size to practice tearing them apart. You should be able to find them around 5 dollars for the 2 line displays.