The only 4x burns I’ve done were HORRIBLE on Benq 1620 / TYG02. There’s no need to burn at such a slow speed when TYG02’s burn so well at 8, 12, and even 16x for some. Mostly, TYG02 is pretty solid at 8x-12x on the 1620’s. I realize chas0039 got his 0 PIF’er on his LG at 4x, but I just don’t think the Benq 1620’s are designed to go that slow.
Post your scans, btw.
Also, again from my experience, B7W9 seemed to give me the lowest PIE’s on average … but, B7V9 is a bit higher, yet seems more reliable somehow (even though it still has issues with WOPC not turning off - which same occurs in B7W9). Try with WOPC on and off. B7T9 is pretty solid firmware, but PIE’s are higher. B7U9 was the worst out of T, U, V, and W … for TYG02 (again IMO).
WOPC off (B7V9, B7W9) … tended to ‘smooth’ out my PIE graph and esp. eliminate the ‘ramp up’ at the end of the disc (with WOPC on). However … WOPC doesn’t always turn off in B7V9 and B7W9. It’s an annoying quirk. ;(