Yamaha DX7 II-D Manual Do Utilizador

 
February 2009  

By CloudsWalker 

www.cloudswalker.com

 

 
Missing Parts on the Yamaha DX7 II-D : 
 
IC5 

Integrated Circuit 16 pin DIL : TC40H174P 

 

6 x D-Flip-flop, can be replaced by 74HC174 

 
IC6 

Integrated Circuit 14 pin DIL : 7405 (TTL) 

 
IC22  Integrated Circuit 28 Pin DIL : HM65256BLP12 
 

SRAM, can be replaced by HM62256LP12 or equivalent 

 
IC23  EPROM 27512 or 27C512 for the new Operating System 
 
IC24  Integrated Circuit 28 Pin DIL : WD1772-PH 

(1986) 

 

Western Digital Floppy Disk Controller 

 
!!! 

3,5 inch Floppy Disk with Drive Select 0 

!!! 

 
CN1  34 pin Floppy Disk Male Connector 
 
 

34 pin flat cable between Main Board and Floppy Disk 

 
 

Power cable between Power Supply Board and Floppy Disk 

 
Parts collecting : 
 
74HC174 is easy to found and found also one IC socket 16 pin DIL 
 
7405 is easy to found and found also one IC socket 14 pin DIL 
 
HM62256LP12 or equivalent is relatively easy to found and found also one IC socket 28 pin 
 
EPROM 27C512 is relatively easy to found and found also one IC socket 28 pin DIL 
 
WD1772 can by found on the Web … or removed from one Atari ST !!! + IC socket 28 pin 
 
The floppy Disk can be 1.44Mb/720kb new … BUT with Drive Select 0 
 
Battery replacement : 
 
It will be judicious at this Time to change your Backup Battery ( 3V CR2032 ) 
 
It’s better to solder a socket. This socket can be removed from an old PC Mother Board 
 
 
Procedure :