I have got a samsung F3 HD502HJ always busy,hot swap did not work.(only SA access - modules were good, but NOT 39 SMRT_TST. and F5 ZONHEALB. and 3D ELOG.)
i have now lack of smart ideas.
Can be that small modules to hang the drive?
(heads are OK already tryed to swap to donor , and back)

Terminal is like this:

*PA VID=0000 PN=0004 Rev=0001- 785x Found
*PA VID=0000 PN=0004 Rev=0001- 785x Found
nChipRev = 53C2U
S_0RV Sensor Circuit Enabled
Shock Sensor Circuit Enabled
SO_1
RPM at Handoff: 1106
Temp : 20 degC
SpinOk
mS1 00000003
SK C:133974 H:0
Loaded FIT ( 0: 0: 1)
ServoTable Loaded. Rev: 0x14
Selective MARC NX Loaded
Ovly loaded to 0x0001CD00
Ovly loaded to 0x1005B800
ReadyTime = 5309659 us

[SWI:00FB7771:04007BC4:08280064]@0
L:04006000 A0A0A0A0 A0A0A0A0 A0A0A0A0 A0A0A0A0
L:04006010 A0A0A0A0 A0A0A0A0 A0A0A0A0 A0A0A0A0
etc..
L:04006210 A0A0A0A0 A0A0A0A0 A0A0A0A0 A0A0A0A0
L:04006220 A0A0A0A0 A0A0A0A0 00000000 0000E100
L:04006230 000000FF 04005C38 00000001 14080590
L:04006240 00000000 0000E705 FFFFFFFF 6000001F
L:04006250 00000002 00000000 FFFFFFFF 1002EF3D
L:04006260 FFFFFFFF 00000000 00000000 1002EF4B
L:04006270 00000000 00000000 00005274 A0A0A0A0
L:04006280 A1A1A1A1 A1A1A1A1 A1A1A1A1 A1A1A1A1
L:04006290 A1A1A1A1 A1A1A1A1 A1A1A1A1 A1A1A1A1
L:040062A0 A1A1A1A1 A1A1A1A1 A1A1A1A1 A1A1A1A1
etc..
L:04006610 A1A1A1A1 A1A1A1A1 A1A1A1A1 A1A1A1A1
L:04006620 A1A1A1A1 A1A1A1A1 000000FF 04005CD8
L:04006630 14081008 00000000 00000200 00000001
L:04006640 10035FAD 04001664 00000000 4000001F
L:04006650 00000000 00001000 00000020 10035FAD
L:04006660 00000000 00000000 00000000 00000000
L:04006670 00000000 00000000 00005274 A1A1A1A1
L:04006680 A2A2A2A2 A2A2A2A2 A2A2A2A2 A2A2A2A2
etc..
L:04006A30 A2A2A2A2 A2A2A2A2 A2A2A2A2 A2A2A2A2
L:04006A40 A2A2A2A2 A2A2A2A2 A2A2A2A2 6000001F
L:04006A50 00000020 00000000 FFFFFFFF 00000000
L:04006A60 FFFFFFFF 00000000 00000000 00008B0D
L:04006A70 00000000 00000000 00005274 A2A2A2A2
L:04006A80 A3A3A3A3 A3A3A3A3 A3A3A3A3 A3A3A3A3
etc..
L:04007FE0 00000000 00000000 FFFF14B5 00000000
L:04007FF0 FFFF0C6D 00000000 00000000 CFDE2210
Cur_SP=04007BAC
FIQ_SP=04007BAC
IRQ_SP=04007BAC
SVC_SP=04007BAC
etc..

*** HALT ***

there is something wrong in the SA/MC.
Are you sure about ROM is native?

Janos