HDD1 Error light

    HDD1 Error light

    Dear sir,
    I faced new problems with my GL35dsr NAS.
    It's about time that my nas fan makes some noises so I decided to clean up my NAS FAN,
    I opened up the case and took out my HDDs , opened up the back panel and every thing and blew up the fan and case in order to clean it.
    but when i packed up everything together and started up my nas I faced the HDD one Error Redlight! right now , beside that redlight, everything seems ok and I have acces to my data (I'm backing up my data ASAP)
    So here i have following questions:

    1- Is it possible that this issue caused because of change in two harddisk slot (maybe I missplaced the HDDs!), and is it possible if you change the HDDs slot the device boot up and work?
    2- if It's not the reason whats the issue? just opening up the case and servicing it can cause dammage to my HDD?
    3- what ever is the reason how can I follow the error and exactly determine the error (any error code or something like that?)
    4- As my problem with the nas FAN is remaining what type of Fan I HAVE to buy for replacement and is there any important thing that I have to consider?
    5- How can I set it up for automated or manual backup , using front USB port, and Does it copy everything on the usb device or just sync it with the usb device and copies just new files ;)

    and at the end I have a major problem with access policies! everybody has access to the public folder and the private folders are just accessible with FTP.
    As long as my employees aren't familiar with networking how can I give them regular SAMBA access to folders but manage the users and accesses to samba shared folders?

    best regards,

    at first a very important Notice!

    You should immediately make a Backup of your data! Everything else is dangerous!

    Q1: possible - If you remove the Hard Drives you have to reinstall them at the same place before. Do not Forget, it is a Raid System!
    Q2: Normally not.
    Q3: No Error Codes - the HDD Error LED says only there is a Problem with this HDD.
    Q4: A two Bay NAS like this is the CL-35B2 but you have to back up your data - you cannot install the filled HDD's into the new NAS. You have to install everything for new.
    Q5: You can use Third Party Software for it. This NAS is not able to independently make backups.