超终端中没有回波出现

我试图得到一台基本的个人电脑到MAX232连接，但完全受阻。我把它煮成最简单的状态：没有单片机，只有我的笔记本电脑和集成电路。我上面有5伏，所有必需的盖子（100nF）。我在插脚2和6之间得到+18V。我的PC电缆，就是这样，插脚2和3短了，我在超终端中得到了回环。当我把这些连接到IC上的终端（2->14和3->13），IC上的跳线12&11时，加电，在超终端中没有回波出现。我也试过其他的232集成电路（7/8和跳线10/9）。我试过不同的集成电路，在黑板上移动，我能想到的一切，没有乐趣。有人能提供一些东西吗？我肯定我错过了一些愚蠢的东西。谢谢。



      以下为原文

    I am trying to get a basic PC to MAX232 connection and am being totally thwarted.

I've boiled it down to its simplest state: No mcu, just my laptop and the IC.

I have 5 V on it, all the requisite caps (100 nF). I get +18V between pins 2 and 6.

My cable from the PC, with just that and pins 2 and 3 shorted I get the loopback in hyperterminal. When I connect these to terminals on the IC (2 -> 14 and 3 -> 13), jumper 12 & 11 on the IC, power up, no loopback echo appears in hyperterminal. I have also tried the other pairs of the 232 IC (7/8 and jumpering 10/9).

I've tried different IC, moved around on the breadboard, everything I can think of, no joy. Can someone please offer something, I'm sure I am missing something stupidly obvious.

Thanks.