How to identify A firmware or S firmware?



I have this question because I tried to crossflash my DH-20A4H to 20A1H just for testing but I reflashed back to CK’s patched firmware (QP5A) and then to QP5B from LiteOn site. My drive came originally with QP5A firmware, this firmware was “A” or “S” version? Actually the drive has “S” firmware. I wanted to try one of CK’s patched firmwares and I read this:

*DUAL: These firmware flashers have two firmwares installed and will automatically detect you firmware type (A/S) and flash the required patched firmware. These packed files are much larger because RAR solid will not work on files larger than 4MB

And also this:


  • It is understood that two different Laser Diodes exist in the A4 models. Please make sure you backup your original firmware using the Flash Utility, before flashing to this firmware, so it can be restored if your drive’s LD does not match the type set in the current patched firmware.

I didn’t backup my original firmware. :frowning:

This firmware detected that I have the “S” version but I don’t know if it’s OK since I crossflashed from a 20A1H firmware (that does not have “A” or “S”) back to 20A4H firmware. Is there a way to know? thanks.


If you didn’t back up your firmware then you would have to look at what the dump of what you have on it now is and look. The firmware packages are supposed to have both and it detects what you have and flashes the correct one. Either way if you didn’t dump original or dump what you have now then you need to use a Hex editor and see if there is an “A” or a “S” listed.

Only way i would know of and it might now be accurate if you don’t have the drives original firmware dump.

Might be able to tell by opening the drive up and looking at the laser itself. Been awhile since i’ve read how to tell but the info is here somewhere.


This is a picture of the DH-20A4H.


This is a picture of the optics. It has written “DS17LS1 I”. The optics are different between this drive and the 20A1H so I guess that it’s correct the “S” firmware, right?