如果显示的不是6,可以作如下处理:1、总清NC，2、不行后更换PCMCIA CARD，还不行，更换NCU。在doc on cd上有一个840D_IAD.DF的，里面有说这方面的情况。
If the digit “6” is not output after approximately two minutes, but:
 another number appears,
 the display remains dark,
 the display flashes,
then proceed as follows:
1. Repeat the NC general RESET process.
2. Switch S3 (NCU) must be reset to “0”.
3. If the NC general RESET does not work, replace the PCMCIA card.
4. If none of these measures work, the NCU module must be replaced.