It is hard to explain one single chinese charater, it is better to try to understand the combinations. for example, ur question, it is hard to 正(zheng4) here, u need to understand the combination, which is 正常( zheng chang). So 正常 means "normal, normally, proper, properly, commom and universal", ur sentence can be translated in english like this: That machine cannot work properly (or normaly).

“那个机器不能 正常 工作了”" That machine doesn't work regularly "or "that machine is out of order" "正常"is a phrase in this sentence which means "normally, regularly" here.

I think is "垂直或符合标准方向（跟‘歪’相对）：～南｜～前方｜前后对～｜这幅画挂得不～。 正常 符合一般规律和情况：精神～｜生活～｜～进行。

符合一般的情况、规律或习惯

nà gè jī qì bú néng zhèng cháng gōng zuò le。it's chinese pinyin,in that case not every character has it's meaning. zhèng has no meaning in this sentence.zhèng cháng can be a adv means normally.