Yamaha TF1 Modules Making Strange Noises

Hi all! I’m new around here so I’ll keep it brief:

I purchased a TX"316" off of eBay, and only one of the three TF1 modules actually plays patches and functions as it should. The other two makes loud crunchy noises, as if something is wrong with the FM chip itself. All three were covered in some nasty brown ooze, and after a nice clean the boards look practically brand new.

I’d hate to lose two TF1 modules, so if anyone has any ideas as to what I should do - let me know!

I am currently trying to reflow the solder on two of these boards… so far one has not gone very well (melted the socket that the TF1 EPROM chip sits in. Yikes).

Brief update - Now I have no output from one of the two bad cards. It takes sysex data, changes patches, etc., but doesn’t make ANY noise.

if the memory batteries died then you need to replace them and do a reset, but you need to also fix the other damage first.