According to your description, I suggest you refer to the following information:
1. You can contact your local HP Gold Service Center to help you clean the machine dust. This operation is likely to cost money. As the HP Gold Service Center has uniform expense management regulations, it is suggested that you can call the staff there in advance to find out the specific information about whether to charge.
2. The contact address provided by HP Gold Service Center is as follows: No.380 Bailu Road, Central District, Leshan.
Tel: 0833-2440285/5 180870
I hope the above reply can help you.
If the above information can't solve your problem, you can log on to www.hp.com.cn/chat,, the online chat room of HP Network, and ask an online engineer to help you solve the problem further. More product information is available in www.hp.com.cn/800..