This is the closest match for SRX 91 firmware:
http://www.s1fw.com/plus/search.php?...e=titlekeyword
5767 is FM chip. The other square IC is CPU.
I suggest also trying SCC91 firmware, it seems to be related.
Do not short just any pins when trying to enter ADFU, only short together the DATA PINS of flash chip (see pinout). Anything else can cause damage.