Why is my Liteon now burning P-CAV?

[faxmaster]

I've had my LiteOn for about eight months now and have not had a problem until recently. I burned a couple of CDs using Fuji media (TY) at 52x and at the very end of the disc, buffer underrun would kick in and then the lead out would be written. The last file would fail CDSpeed's scandisc, although it was readable in Windows. Other times, about 3/4 of the way through, the drive would spin down then finish the rest of the disc (p-cav).

I decided to try burning a CD with CDSpeed to see what was going on. This is what I got: .

This is one CD out of a 100 pack and the first ~50 have been problem free, but I've been having problems with the past five or so. I haven't been able to test another batch/brand of CDs yet, but is this probably a media problem?

[Nogib]

Something is f'd up as that is not what P-CAV looks like!!! Either something is wrong with your drive or you have some bad discs (happens). Try updating to the latest firmware for your drive 6S0F and see if that helps any:
http://www.liteonit.com/webfw/LTR-52246S/R526S0F.zip

[rdgrimes]

This is typical behaviour when you're burning the media too fast. You may or may not be able to find a firmware version that is less suseptable to this, but many of the 6S drives do this, particularly with TY. All you are seeing is the invocation of SmartBurn (not buffer under-run), due to an "over temp" situation. High case temps and prolonged drive use will aggrivate this. the 6S drives can also have an issue with creating an unreadable sector at the point where the drive pauses, if it occurs at high speed. The only way to deal with this is to set a lower burn speed, like 40x. The slower speed may actually be quicker.
This is what SmartBurn is designed to do. As you can see, it paused, then dowshifted to 24x, which is why setting it to 40x in the first place will be quicker. My 6S drive has never burned TY at 52x, or even 48x, without slowing at some point.

It's interesting to note that the 7S drive does not pause when it downshifts, it does it "on the fly", which is quite remarkable.

[faxmaster]

Thanks for the explanation. I guess I'll be burning the rest of these discs at 40x, as doing so eliminates the problem.

[Harrier]

This is typical behaviour when you're burning the media too fast. You may or may not be able to find a firmware version that is less suseptable to this, but many of the 6S drives do this, particularly with TY. All you are seeing is the invocation of SmartBurn (not buffer under-run), due to an "over temp" situation. High case temps and prolonged drive use will aggrivate this. the 6S drives can also have an issue with creating an unreadable sector at the point where the drive pauses, if it occurs at high speed. The only way to deal with this is to set a lower burn speed, like 40x. The slower speed may actually be quicker.
This is what SmartBurn is designed to do. As you can see, it paused, then dowshifted to 24x, which is why setting it to 40x in the first place will be quicker. My 6S drive has never burned TY at 52x, or even 48x, without slowing at some point.

It's interesting to note that the 7S drive does not pause when it downshifts, it does it "on the fly", which is quite remarkable.

Which is why in comparison , 6S's have slightly better burns, quality wise (The best i've seen with 7S is ~0.3. My LTR52246S does 0.05).

[rdgrimes]

Which is why in comparison , 6S's have slightly better burns

I'm afraid I don't see the connection.

[Harrier]

Which is why in comparison , 6S's have slightly better burns

I'm afraid I don't see the connection.

I might be wrong but isn't smart-burn invocating is due to temp. situation etc that actually causes higher error rates?

[rdgrimes]

Smartburn is not connected to error rates, but to the temperature of the laser/media. Indirectly, it results in lower rates. It does not follow that a lower laser power means lower error rates, the opposite is true at the highest speeds. The line between optimal calibration and over-temped media is very thin, and the cyanine-based dye is the least tolerant of over-temp. The Pthalo-based dyes are more resistant to over-temp, but that same quality makes them less likely to respond well to the high temps involved in 52x burning. From what I can see, the 7S has superior laser calibration because it can burn very fast on a wide range of media, and appears to adjust calibration very quickly. The difference between the 6S and 7S C1 rates is insignificant, except when you consider that the 7S will acheive those same rates on more media types, and at higher speeds. But it's not "super-drive", crappy media is still crappy media.

[Inertia]

rdgrimes, I agree that faxmaster's graph is indicative of "summer-time slowdown". I have two LTR52246S drives and both were capable of burning TY at 52x with low error rates under normal weather conditions (not too hot).

That is, until we encountered some days over 100° F, when the temperature in the house approached 80° or slightly more. Although my computer cases are well ventilated, the higher temperatures showed up in higher error rates and some C2 coasters with TY discs when burned at 52x. This was happening to one burner in particular, and the other seemed relatively unaffected. This was the first time that TY had delivered C2 coasters, and I thought perhaps the burner was failing until I realized it was just the heat. The stress of burning at 52x, immediately doing an error check at the highest speed, and then successively repeating the process took its toll.

After I figured out the problem, the next day I retested the discs that had shown C2 errors (when hot) and most C2s had disappeared. As you mentioned, the pthalocyanine discs (Maxell 40x) were more resistant to heat, and still burned OK at 52x with low error rates. As the weather cooled a bit, the TY problem disappeared.

One of the coasters did reveal the unreadable sector issue. If this is caused by the invoking of SmartBurn with 52246S drives, it is too little, too late, and defeats the purpose of SmartBurn. It isn't so "smart" if it causes an unreadable sector instead of preventing it.

[rdgrimes]

It isn't so "smart" if it causes an unreadable sector instead of preventing it.

Agreed, this happens fairly predictably on my 6S (maybe 1/2 the time), but only if the pause occurs late in the burn. It improves with later firmwares. I still just burn everything at 40x,it's often quicker and always results in a very good disc.

[faxmaster]

I have two LTR52246S drives and both were capable of burning TY at 52x...

As was I, that's why I wanted to know if something was bad with my drive. I've burned about 100 Fuji's at 52x without a problem, and about 50 in this pack of 100 that I'm now going through.

It improves with later firmwares.

Is there any reason for me to upgrade 6S0F from D?

[Harrier]

Yeah:
"Strengthen the stability of the "OVERBURN" function."

[rdgrimes]

Is there any reason for me to upgrade 6S0F from D?

Actually, i found 6S0F to produce higher error rates, but it may have less trouble with the posted issue, the answer is to try it and see.