As removed from a NAD CD Player Model: 5255
This NAD model was released to the market in the early 1980's
The lovely Toshiba laser head had failed and I have discovered they are EXTREMELY difficult to find replacements for, so the complete machine has been parted out.
This is the complete (fully functioning) main printed circuit boards of the equipment. All primary functions such as player transport operation, digital to analog conversion, filtering etc are undertaken by these boards. They are laid one on top of the other, separated by plastic lock posts.
Both boards are single sided and discrete componentry - there is no SMD on these boards.
If not being used as complete replacement boards, a good source of replacement hard to find components.
NAD CD Player 5255
Main printed circuit boards, one sitting on top of the other.
NAD extensively used Toshiba product in this equipment, most of the devices below are Toshiba sourced.
Top board populated with these devices:
TA75458 Dual Op Amps
TA7256P Dual Power Amplifier
2SC2878 30V 300mA transistors (numerous)
and lots more!
Rear right angle mounted board
TC91787AF
TC91779F
TC5516AFL 2048 word x 8 bit Static RAM
Underneath board:
TMP4740 4 bit microcontroller
TD6705AP DAC
AFL89GB Murata filters (2 - one for each channel)
and lots more!
All interconnecting with these boards is via "push-lock" connectors EXCEPT the power supply from the PSU - these were wire-wrap terminals and new connections could either be wire-wrapped again or soldered to the posts. I have left short colour coded tails on the posts to assist in identifying which wire goes where.
I have also included a photograph of the interconnect wiring PRIOR to dismantling - this may help as well.
COSMETIC CONDITION:
There is no physical damage to any of these components
All items are clean
TESTING:
Fully functioning prior to removal from the 5255
After removal these boards were not further tested, little point really as it all unplugs and unlikely to be damaged during dismantling. Standard ESD precautions taken and stored/supplied in an ESD protective bag - sealed.
I do NOT have the schematics for this equipment.
