bootcamp doesn't work after hdd in optical bay

Hi everyone,

I have a macbook pro 2012 mid 13' which runs on HDD orginally.

A year ago, I bought a Samsung SSD to swap the old HDD. Mac OS was cloned to the SSD and a windows 7 was clean installed using bootcamp. Everything works fine.

Recently I find the optical driver broken, so I take it out and install the old HDD in the optical bay.

Suddenly I cannot boot into windows 7, black screen with blinking cursor, Mac OS remains functional.

If I disconnect the HDD from the optical bay, then I can boot into windows 7 and both systems work fine.

Once I connect the HDD in the optical bay, it won't let me boot into windows again.

Problem remains after formatting the HDD, using windows installation to repair things like Bootrec.exe /FixMbr, FixBoot, RebuildBcd.

Diskutil list shows results below, where disk 0 is SSD with windows 7 and Mac OS, disk 1 is HDD.

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.1 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_APFS Container disk2 299.9 GB disk0s2

3: Microsoft Basic Data Winddows 7 200.0 GB disk0s3

/dev/disk1 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.1 GB disk1

1: EFI EFI 209.7 MB disk1s1

2: Microsoft Basic Data HDD 499.2 GB disk1s2

/dev/disk2 (synthesized):

#: TYPE NAME SIZE IDENTIFIER

0: APFS Container Scheme - +299.9 GB disk2

Physical Store disk0s2

1: APFS Volume Macintosh SSD 247.7 GB disk2s1

2: APFS Volume Preboot 21.8 MB disk2s2

3: APFS Volume Recovery 516.1 MB disk2s3

4: APFS Volume VM 8.6 GB disk2s4

Looking forward anyone's help.

Many thanks.

All the best,

L