Apparently it will initialize itself from a cart after the battery is replaced. RebootĪt power on, the DX7 realized its static RAM was filled with garbage so it prompted for a cart to be inserted. I got one on ebay and it is working perfectly. These can be found on ebay for around $10. It is a Mitsubishi M5M5118P-15L (2Kx8bit SRAM). IC21 is one of the three SRAM chips on the mainboard that comprise the internal memory. I now have both the SER-7 special edition ROM and the original v1.8 DX7 ROM. If you ask nicely, one of the ROM sellers on ebay will be more than happy to burn that. bin file of the original DX7 ROM (v1.8) is available in the YamahaDX Yahoo group's file collection. On ebay you can find folks selling a "Special Edition" (SER-7) version of this ROM for the DX7. IC14 turns out to have been a Toshiba TMM24128AP (16Kx8bit ROM). So, going back to stock means replacing them. Installing the E! card requires pulling IC14 and IC21. Fortunately, there are plenty of resources for DX7 repair on the Internet.
I decided to revert back to the original stock setup, but this DX7 didn't come with its original pre-E! chips. I haven't come up with a clever solution for this yet.Īdditional symptoms of a loose E! board are mainly refusal to boot with displays ranging from "88" on the LED display and a row of blocks across the LCD to random segments lighting on the LED display. The pins aren't long enough to be inserted completely into the ROM socket on the mainboard and this lifts the pins that go into the SRAM socket. In fact, the design of the E! card precludes it being fully seated. Turns out the E! card was not fully seated into the main board.
Instead, the memory was going just like it was for me. I'm guessing the battery wasn't actually bad. The previous owner had had it worked on to replace the battery. Time to take it apart and see what's going on. But then after letting the keyboard sit for a few days, I turned it on and the last half of several of the banks was garbage. I figured it was just a fluke, so I backed up the banks and then filled them back up with the factory ROMs. The keyboard worked fine at first, although it seemed strange that the last half (patches 17-32) of a couple of the banks in the internal E! memory had garbage in them. And, unfortunately, a finicky E! Grey Matter Response upgrade. Came with a TSA approved case and a two bank RAM cartridge. Only one previous owner (and his father). Fast forward to August 2012, and I own one. The keyboardist in a band I was in had a DX7 and left it at my house for a weekend along with the manual. The story begins for me back in High School in 1985. Ted's Yamaha DX7 Page Ted's Yamaha DX7 Page
0 kommentar(er)
