Lite-on slimtype 833S



My Acer Aspire 3002LMI uses a lite-on slimtype SOSW-833s VRS2 DVD writer that is supposed to be capable of burning DVD + - and DVD + DL, I have no problems with writing to 8 x DVD+ but can’t write to 8 x DVD- (max speed is listed as x24 for both + and -), is this liley to be hardware, software or media related?



Welcome to cdfreaks :slight_smile:

The max speed you mention is most likely the max read speed. What DVD-R media are you trying to use? You can use Nero CD/DVD Speed or DVD Identifier to find out the media ID. It’s more likely to be media if DVD+R media works okay…

Can you please send me the firmware from your drive by using this tool to extract it.

You will find my contact details here:


I have also tried this on Maxell media as my DVD player is not to keen on DVD+ even trying to burn with a lower speed didn’t work. Any more ideas?



I’m using Acer notebook (Travel Mate 2413 WLMi) with slimtype SOSW-833S too, VRS3 firmware. But there’s no autobitsetting checkbox in the OmniPatcher 2.4.3 when firmware is uploaded to this program. OP manual says that this feature were removed for the drives that remembers current bit set after reboot, for example, maded with LiteOn bookType utility. My drive doesn’t allows to change disc booktype, neither with LiteOn booktype utility nor enable it with related OP checkbox.

And another big problem of this drive - slow DVD burning speed… Speed is never reached value selected into burning software (Nero, Nero premium). Recjrder hardware buffer indicator during burning sequentially drops from 98-96% to 21-25%, speed at that moments slows down to 325 kb/s !!! So , this drive burns DVD+R 4.7 Gb disks with MKM and YUDEN T02 media with 4 Gb of data (ISO or UDF filesystem - doesn’t matter…) for about 40 mins… Actual recording speed for the ANY 4x media is 2-2.3x…
833S works as primary slave. Primary master is 60 Gb HDD UDMA100. UDMA enabled for both devices, burst transfer rate for 833S estimated with Nero CD-DVD Speed is 22 mbytes/sec.

Can you comment this situation ? Or give any advices ?


Hey Code King,

Did you get the firmware, if not I can extract mine if required.



Kosti, I don’t have much to do with the slimtype drives. I have VRS3 and it is on my site but I’ve never looked at the firmware in detail. Is not the solution for VALDORF (and I may be wrong), to flash it to VS04.


No problems, I don’t think I’ll be flashing just yet.



sorry to interrupt but i found in your page a VSR4 fw version… what is it in fact? is it a nice upgrade for this drive or should i just wait for a miracle to put this drive working as it was supposed to do? please help me, i can’t burn decentlly, i can’t even read some dvds!!! i’m using 3rd fw version, tested 2nd and nothing! i’m using an acer laptop, aspire 3614lmi…


From the look of things most people here that have this drive have an Acer notebook. I myself recently purchased an Acer Aspire 1640 series notebook and was unlucky enough to get this piece of $#!% drive. I called Acer and through speaking to a couple of the support techs finally was able to find out that they also use a Panasonic drive in these machines and was able to get them to send me one of those drives in exchange for the Lite-ON drive. The Panasonic drive that I received was a UJ-840D. This drive is 8x DVD±R, 4x DVD±RW, 2.4x DVD+R DL, 5x DVD-RAM and 8x DVD reader. From the very first disc I burned I noticed a huge difference. Burn time went from 50 minutes for a full disc to around 15 minutes. The only downside is that I haven’t yet found a way to set the booktype on DVD+R media. For those of you that don’t have any success exchanging your Lite-ON drive for another make from your laptop manufacturer you could always at least add DVD-R DL burning ability by cross-flashing the drive to a Sony DW-Q58A drive with firmware UYS3. The firmware is available from the Codeguys site. I successfully flashed my 833S to the DW-Q58A before exchanging it and then back again before I sent it back to Acer. Anyhow, that is my success story with the piece of $#!% 833S, I replaced it and now it works great! Best of luck to everyone else.


88keyz, I have the Matshita UJ-840D in my Acer 4102WLMi. I didn’t know it was a 5x DVD-RAM drive. The downside to the 840D drive is that it will not do bitsetting, there will never be a RPC1 patch and there will probably never be a firmware update going by past Panasonic OEM drives. Unfortunately the drive uses ZCLV for all media (starting at 2x) and the drive burns some well known media at much lower speeds than it’s rated at, an example is 8x CMC MAG AE1, which it only burns at 2x. But generally the burn quality is good and that’s the most important thing. :wink:


Thanks for the feedback CodeKing. That’s too bad about the bitsetting and really too bad about the firmware updates but the fact remains that the UJ-840D is a far superior drive in terms of its media writing and compatability than the 833S in my short experience with the two drives. Writing at a minimum of 2-2.4x is much better than the maximum of 0.7-1.9x that I was getting with the Lite-ON drive. I’ve owned a couple of other Lite-ON drives in the past and loved them but I’ll be sure to avoid the DVD±RW drives in the future.


Valdorf wrote

And another big problem of this drive - slow DVD burning speed… Speed is never reached value selected into burning software (Nero, Nero premium). Recjrder hardware buffer indicator during burning sequentially drops from 98-96% to 21-25%, speed at that moments slows down to 325 kb/s !!!

I’m getting exactly the same symptoms on an Acer Aspire 1650. I sent it for repair and they replaced the Phillips drive with the SOWS 833 and the problem remained. Acer have asked me to book it in for repair again, but I’m loath to as I was without the laptop for 3 weeks last time

I seemed to get better result with Nero and VRS2, but I’ve lost the backup BIN VRS2 file and am now running VRS3 - is there anywhere I could get VRS2 as I’ve searched endlessly?

The original drive was a Phillips SDVD 8441. If two different drives have the same symptoms, is there some other possible reason? any thoughs appreciated.