Purchased a couple of 'new' HDDs from an unusual source (website in Singapore with limited history) - 2x 18TB WD HC550s - sold to me as new.

Given their price, I expected cold spares and/or manufacturer refurbished. Anyhow, got the drives & installed them, working fine and no immediate errors after a quick smart test, and ran preclear on one of them I think. But I've been looking at the drives SMART error logs, and they show the following:

ATA Error Count: 88 (device log contains only the most recent five errors)
&
ATA Error Count: 105 (device log contains only the most recent five errors)

All 10 (5 each) of the errors I can see all are the same:

Error 105 occurred at disk power-on lifetime: 0 hours (0 days + 0 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 40 43 00 00 00 00 00 Error: UNC at LBA = 0x00000000 = 0 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- 60 08 00 00 00 00 40 00 00:04:20.472 READ FPDMA QUEUED ef 10 02 00 00 00 00 00 00:04:20.334 SET FEATURES [Enable SATA feature] ef aa 00 00 00 00 00 00 00:04:20.334 SET FEATURES [Enable read look-ahead] ef 03 46 00 00 00 00 00 00:04:20.334 SET FEATURES [Set transfer mode] ef 03 0c 00 00 00 00 00 00:04:20.152 SET FEATURES [Set transfer mode]

All error occurred at 0 Hours, and all are the same error: uncorrectable read errors at LBA 0 - thoughts?

UNC at LBA is never great, but it's sector 0, run an extended SMART test, if it passes, they are OK for now.

Good to know, I'll try and run an extended SMART test, see what shows up.

I chatGPT'd (forgive me...) the errors - it suggested to monitor, but also these errors (as both drives show the same sector & same error) that it could have been caused by refurbishing processes - is this possible, or are these likely old drives that have just started to fail?

The below current, normal SMART test looks ok though?

#	Attribute Name	Flag	Value	Worst	Threshold	Type	Updated	Failed	Raw Value
1	Raw read error rate	0x000b	100	100	001	Pre-fail	Always	Never	0
2	Throughput performance	0x0005	136	136	054	Pre-fail	Offline	Never	96
3	Spin up time	0x0007	099	099	001	Pre-fail	Always	Never	66
4	Start stop count	0x0012	100	100	000	Old age	Always	Never	2
5	Reallocated sector count	0x0033	100	100	001	Pre-fail	Always	Never	0
7	Seek error rate	0x000b	100	100	001	Pre-fail	Always	Never	0
8	Seek time performance	0x0005	140	140	020	Pre-fail	Offline	Never	15
9	Power on hours	0x0012	100	100	000	Old age	Always	Never	239 (9d, 23h)
10	Spin retry count	0x0013	100	100	001	Pre-fail	Always	Never	0
12	Power cycle count	0x0032	100	100	000	Old age	Always	Never	2
22	Helium level	0x0023	100	100	025	Pre-fail	Always	Never	100
192	Power-off retract count	0x0032	100	100	000	Old age	Always	Never	11
193	Load cycle count	0x0012	100	100	000	Old age	Always	Never	11
194	Temperature celsius	0x0002	059	059	000	Old age	Always	Never	35 (min/max 22/40)
196	Reallocated event count	0x0032	100	100	000	Old age	Always	Never	0
197	Current pending sector	0x0022	100	100	000	Old age	Always	Never	0
198	Offline uncorrectable	0x0008	100	100	000	Old age	Offline	Never	0
199	UDMA CRC error count	0x000a	100	100	000	Old age	Always	Never	0

That looks fine