Exchange tips and tricks for the Akai MPC4000
By CharlesRandolph Tue May 14, 2019 4:27 pm
JUKE 179r wrote:@Sense-A... thanks for the research and info. Please keep it coming.
My screen looks like it's bleeding as in having different colors. I was looking at the LED screens for the 4000 on ebay but they are £150/$195.


That's not bad, considering how many years the screens last.
User avatar
By JUKE 179r Tue May 14, 2019 5:53 pm
Just throwing this out there... The Roland MV-8000 & 8800 has the VGA and mouse option also. It's the ****!!!
Sense-A wrote:If anyone can link me to the service manuals for either the MPC 3000 or MPC 60ii then I can begin exploring whether or not one of these can be adapted for the MPC 4000 or the MPC 1000/2500.

I can upload the 3000 service manual tonight.
*EDIT* here it is from MPC Tutor...
MPC3000 Service manual
MPC60 Service Manual ... it's 90% like the MPC60 MkII
CharlesRandolph wrote:Also what did they do, in order for the MPC 1000 and 2500 to have the Large LCD Screen?
Image

You'll need the JJOSXL so you can use the bigger screens.
By CharlesRandolph Tue May 14, 2019 9:00 pm
JUKE 179r wrote:You'll need the JJOSXL so you can use the bigger screens.


What about the screen connection itself? How was it modified for 1000/2500 or was the screen already built that way? Also would the MPC 4000 OS have to be updated, so it can mirror the LCD to an external monitor or can the video cable be split to feed the LCD and the external monitor?
By richie Tue May 14, 2019 10:50 pm
No modifications are required. Both the regular and large 1000/2500 screens use off the shelf LCD screens with T6963C controllers. JJ OS is required to map to the lower half of the larger screen otherwise all you will see is the top half of the screen.

If you go on eBay and write "T6963 LCD" you will see what I am talking about.

It is possible to tap the serial output on the T6963 and have a pass through like a pi to process the data i/o from the controller.
By Sense-A Wed May 15, 2019 1:49 pm
CharlesRandolph,

You are right. $200 is a fair price for a LCD that is ready to plug in and is warrantied. I don't discourage anyone from buying one from a reputable merchant such as MPCstuff or other reputable dealers.

Tapping the MPC 4000 display would require a splitter and then a separate display card that translates the LVDS to RGB. Something like the 2seemy card you mentioned, or the MPC 3000 VGA out card.

Image

I found a schematic for the IB-CRT card in the MPC 3000. You can see that it first splits off the signal to return to the LCD block before sending a duplicate signal to the IC's. It has several microprocessors, or integrated circuits (IC's) that do the calculations to output the horizontal sync, vertical sync, and video information that is fed through a VGA cable. There's quite a few connections and I don't know how readily I would be able to obtain the IC's on the market considering the age of the MPC 3000. I also believe that the 2seemy is likely a newer design and utilizes some more modern circuitry, apparently one IC, that accomplishes what it took several to calculate during the MPC 3000's time. It is possible that the MPC 3000 vga output board would work with an MPC 4000 or MPC 1000. However, the pinout diagram is labeled different, has a different number of pins, and might not be as easy as a one to one connection. The MPC 4000 has 4 data pins and an alternation control signal and a 24V connection. The MPC 3000 has a "Load" connection and apparently does not have 4 data pin connections.

Image

Image

The larger screen in the MPC 1000 did not require a translation of video signal. The connections for the larger screen were the same as the smaller screen. JJ only had to modify the operating system to make use of the extra real estate and modify how the OS sends the display data. The technical stuff is more complicated than that and I am not the one to explain it.

The 2seemy device is interesting. I spent some time last night reading about it. I feel bad for the hell that so many TASCAM DM 3200 and 4800 users went through for what looks like a very expensive device. However, the 2seemy device is the closest thing to an aftermarket design and implementation that works. Even more interesting is that it includes a USB connection and it is a small factor form that would easily fit inside MPC's. The flash website did not work for me, but now I am also researching and looking for schematics and information about this 2seemy module, including what parts it uses and how it works.

Thanks everyone for your help! I probably won't figure this out on my own so please continue to contribute, correct anything I have wrong, and help fill in the blanks or suggest solutions utilized in other models and devices. Any device that has an embedded LCD screen with a vga or s-video output that mirrors the LCD display likely has technology that can be imitated or helpful. I'm looking at the Roland S-550, S-760, and MV8800 as well, but have not focused on them because I don't believe they are necessarily mirror images of the LCD screen but rather a separate video feed coming from the devices' motherboards and operating systems. Though I may be wrong.
By richie Thu May 16, 2019 3:28 am
CharlesRandolph wrote:What would be needed to TAP the MPC 4000 Display?


Like I said, a pass through device such as a pi or an arduino with additional code to translate to serial i/o.

That comes with its own issues of having to do a lot of trial and error to determine the correct timings or you will end up with the same issues that people with the MPC 2000/XL replacement screens still have til this day.

I believe the person out of the uk charging huge prices for his OLED 4000 screens simply sourced the same driver controller and had new boards manufactured and custom OLED screens tooled. It's the same difference with the S series / MPC 60 / 3000 screens although those are just the normal 240x64 screens sold on ebay with a new board sans the T6963 controller with traces run to where it is needed, as the S series , 60 and 3000 have their LCD driver on the mainboard.

The person that would be able to provide excellent insight is that dude out of France that made the LED kits for stock 4000 screens.
By Sense-A Thu May 16, 2019 2:15 pm
Someone at MuffWiggler posted some very useful information.

The MPC3000, as well as a whole host of other AKAI devices from the era, use the now discontinued Sanyo LC7981 LCD Controller in graphic mode. https://www.crystalfontz.com/controller ... LC7981/246
In the MPC3000 & MPC60 The LC7981 is mounted on the I/O board. The displays used don't have the controller onboard. - Kurt.Koolbrain


When you read the datasheet for the SANYO LC7981, you realize that it is just a small microprocessor doing a bunch of mathematical calculations. So you take the data coming from the MPC 4000 video controller and do some math to calculate a video, Hsync and Vsync data stream. Sounds easy but it's not. Fortunately, the microprocessors we need to design a circuit board to do this likely already exist. A bit of programming may indeed be necessary to fine tune the clocking/timing/frequency.

The parts that were used to make the MPC 3000 IB-CRT are still obtainable from places such as aliexpress and a couple other merchants. It would cost me about $100 in parts and shipping but I would have enough for at least 5 prototypes. Utilizing these old parts, with slight modification, could possibly achieve a solution.

MPC 3000 IB-CRT Parts Cost Quantity
IC HD74HC590P Time Relay $2.88 5
IC HD74HC590P Time Relay, processes clock signals $2.88 5
IC LC3517BL-15 Static Ram Quote?
IC HD74HC595P Time Relay, sends 8 bit data to static ram and to HD74HC166P which in turn outputs video signal $10.25 100
IC HD74HC166P Takes 8 bit data from static ram and outputs video signal to RGB $2.21 5
IC 18CV8PC-25 L3022A $10.34 10
IC 18CV8PC-25 L3022B Takes data from Static Ram and Outputs the Vsync $10.34 10
IC PALCE 22V10H-25PC L3022C $7.41 5
IC 18CV8PC-25 L3022D $10.34 10
OSC X TAL TD308C 10MHZ Oscillator? $23.55 2

However, I'm still leaning towards getting someone from Texas Instruments to assist me in finding a more efficient solution.

I reached out to the technical department of 2seemy but have not heard back. I don't expect people who have already designed similar solutions to openly share their research, schematics, and designs.

I assume the French guy that richie refers to is the person selling the LED displays on eBay and Reverb. Again, I don't expect that he will want to share his research and work with a stranger on the internet for free when he is already attempting to run a business by supplying LCD solutions himself. However, it doesn't hurt to try. I'll reach out to him this weekend and see if he wants to share information.

It's frustrating because the internet is full of solutions to convert vga and hdmi to lvds. So there's lots of solutions to make modern video signals backwards compatible with old displays and tv's, but there's hardly any solutions to make old video signals forward compatible with modern displays and tv's. If I wanted to convert an HDMI or VGA signal back to a LVDS signal, I'd already have a working solution the market readily provided. There's no way that I know of to reverse the signal path and conversion on these ready solutions.

Also worth noting is that modifying a laptop display, which is native to LVDS, might be an easier solution than trying to output to VGA.
User avatar
By JUKE 179r Thu May 16, 2019 2:53 pm
Hey @Sense-A ... I got the pdf MV-8000 service manual if that can help you to look at the VGA configuration?
By richie Thu May 16, 2019 8:32 pm
Sense-A wrote:I assume the French guy that richie refers to is the person selling the LED displays on eBay and Reverb. Again, I don't expect that he will want to share his research and work with a stranger on the internet for free when he is already attempting to run a business by supplying LCD solutions himself. However, it doesn't hurt to try. I'll reach out to him this weekend and see if he wants to share information.


No no man, there was someone on here (name escapes me at the moment) that made his own LED retrofit with a brand new LED controller to use with the stock MPC 4000 displays. That way there would be no more need to replace CCFL bulbs whenever the gas starts running out on one.

The person selling the new LED / OLED displays is out in the UK and charges $300+ for the screens. A lot of reviews online state the guy is a jerk so I would not even attempt to rationalize the response he'd give to a stranger on the internet wanting to know what he did, essentially destroying his own business. :lol:

I'm not sure if Texas Instruments would be of any use as I believe that they were absorbed by Intel a few years back but stranger things have happened before.
By Sense-A Fri May 17, 2019 1:25 pm
Yesterday I received the LCD screen which was pulled out of an Emerson CSI 2120. I paid $40 for it because it was used and had glue on the front of it holding a touchscreen sensor sheet on it.

Here are pictures comparing it to the OEM MPC 4000 LCD screen. The Emerson screen is on the top in both pics.:

Image

Image

Someone on the internet selling replacement displays claimed that the original OEM MPC 4000 was cheaply made in China. But as you can see, the controller board at least, it was produced in Japan.

Notice a few key differences. Slightly different model numbers handwritten in. The Emerson LCD has a female connector whereas the OEM MPC 4000 has a male connector. This means that I have to either desolder the connectors off the boards and reuse the OEM one, or create my own ribbon cable using arduino jumper cables (which is how I temporarily hooked it up and tested it). You will also notice the touchscreen overlay on the emerson. I was able to gently scraped this off using an old plastic debit card. It was fairly easy to peel off. The cable that connects to the invertor is also different. Again, I used arduino cables to hook it up. Proof that the screen works:

Image