Repair all Chinese Fones with only RS232 cable

[bond95]

Repair all Chinese Fones with only RS232 cable{No Need Any Box....}


Here is pinouts...

http://techpubs.sgi.com/library/dynaweb_docs/0650/SGI_EndUser/books/MSB3xx_UG/sgi_html/figures/db9.pinouts.gif

Where.

Pin2-RX
Pin3-TX
Pin5-GND

Примечание

For repairing china phones with RS232 cable must be add a input/output buffer stage to Tx and Rx signal to boost signal voltage.

use this 74hc14 (14 pin) ic to boost the Rx, Tx voltage