What to do when RS 232 Port is not available?: Download now “STB EROM Upgrade” software from internet. Errors stating 'initialize STB sdram is failed' and also 'Set stb memory error' when I try different versions of the stb erom upgrade software. Is there a newer version of the file? Bal971, #5. Openbox v8s erom Upgrade tool Discussion in 'Openbox Satellite' started by jonesl129, Jan 16. In the market it is easy to available DB9 modem cable but sometimes not easy to avail RS232 cable, Both cables looks same, same connector and plugs. Now days in all PC DB9 pin serial male port easily available so you need female to female DB9 / RS232 cable. Asus Rt-ac68w Firmware Upgrade Wrong Versionįor upgrade set-top box by pc, RS232 cable is most important accessories.This post is about only for RS232 cable, if you want how to upgrade then click here. If you want to upgrade your set-top box software by PC or if you have broken STB which you want to recover by RS232 cable then this post is for you.