Tag Archives: Midas MC21605A6WD-BNMLW

E-MU Emulator II LCD screen change

One thing that sooner of later will die on your EII, if hasn’t already, is the backlight of the lcd display.  There are basically two things that can go wrong: The backlight itself or its transformer.

The backlight The original EII display don’t use leds for the backlight as modern displays do, but another kind of lamp. These can be replaced, but I’ve understood that it’s quite a lot of work, and it’ll definitively die on you again.

The transformer transforms 5V to a much higher that supplies the backlight with power. These kind of transformers often emit a high pitched frequency which can be quite annoying.  Since my transformer didn’t sound at all, I thoguht that this might be the faulty component, and not the backlight itself. The transformer used on the EII is the NEC NEL-D32-46.

The solution is to replace the whole lcd display with a newer one that has led-backlight and remove the transformer. On my EII I suspect someone has been doing some kind of operation on the display before, since the display wasn’t physically connected to the display.

Parts

EII OEM displays can be bought on eBay for a lot of money, and they will die sooner or later. There are also other modern “EII/SP1200 replacement lcd displays” available, but they are way overpriced.

Probably any standard modern 16×2 lcd display will work, but be careful when you look for one that it has the correct dimensions, 84×44 mm. Most 16×2 displays that you find are 80×36 mm, and they a) won’t fit in the standard mounts b) require a new flat cable to be soldered to the upper board. Take my advice and get one in the correct dimensions! There are some lcd displays avaible that don’t have backlight, you don’t want one of those. The lcds with backlight are usually 13.5 mm deep, the ones without 9mm.

I found a suitable lcd display manifactured by “Midas” on the UK eBay for around $30 including shipping to Sweden. They can be found much cheaper on Farnell and RS Components, but they require that you purchase stuff for a minimum amount.  I chose the model with blue background and white characters.  You’ll also need a new hex-inverter chip and two short wires for the power.

  • Midas MC21605A6WD-BNMLW 16×2 lcd display 84×44 mm with backlight, I bought it from here
  • Hex inverter Texas Instruments SN74LS04N (this was strangely enough in a zipper bag included with my EII when I bought it…)
  • A pair of 5 inch red and black wires

Replacing the display

Start by opening the EII and remove the upper board that the display is mounted on. More details on that in the E-MU Emulator II slider pot A replacement post.

First thing was to remove the transformer. I cut the melt glue and then used a solder sucker and some heat to remove it. I then soldered the red and black wire to get 5V and ground from the same place as the transformer did.

Next thing, and probably the most time consuming one, was to desolder the 14 pin flat cable from the old display. First I removed the four nuts so that the display was loose from the board. I then had to use plenty of heat and soldering wick. Because of the heat, the insulation on the flat cable took a hit and split itself, but that was actually not a problem, I see no risk in short circuits.

Next step was to solder the 5V and ground wires to the new display, 5V goes to hole 15 and ground to hole 16. The flat cable’s 14 pins goes to hole 1-14. I then reattached it with the nuts and nylon spacers to the board, it was 100% perfect fit!

Just for fun,  I booted the EII to see if my desoldering action had caused any damaged, but it didn’t! I did see the garbled text in the new lcd that I’ve read about in forums when you don’t have the correct hex inverter.

I turned the EII off and located IC25 on the right lower board, it’s near where the floppy cable connects. Make sure you work the right board and not the left, because there’s an IC25 on the left as well with the same physical dimensions! I removed the original RCA H 506 and replaced it with the SN74LS04N and booted. It worked, and it looked great!

Conclusion

I really recommend doing this switch, the display is very easy to read and also has a good display angle. The hardest part is desoldering the flat cable, other than that the swap is straight forward. Make sure you get a display in the correct dimensions as well, 84×44 mm, and double check that it features backlight.