Roland TR-909 MITSUBISHI EPROM V4.0 latest firmware upgrade

Description

Latest firmware version for Roland TR-909 fixing timing problems as recommended  in Roland's Service Information  No. 100236.
This eprom I'm selling is a MITSUBISHI, the only brand proved not to fail in some TR-909 models. There are other V4.0 eproms for sale over there, but probably they are not MITSUBISHI, as these ones have been discontinued long ago and are hard to find and more expensive, but they are the most reliable for your TR-909.
You'll have to de-solder your eprom and solder this one in the same position (take note of the notch on one side). It is recommended to solder the eprom directly to the TR-909 board, as you may have bad contact problems overtime using sockets (we've already repaired some TR-909s for this reason).
If you want to know which firmware version do you currently have, power on the unit while holding down the 'Track 1' button. One of LED's 1-4 will illuminate, indicating your version # 1-4.
Fast international shipping by registered mail with tracking number provided.