Hello mg73, I am not sure you'll find these schematics...As a TimeLine distributor in the 90's we had not them... we sent back the faulty units to the factory and they sent us new units. Like you I would check the RAM chip. It can help if you have another module...I suppose you have two modules ? I still have a couple of LYNX 1 if it can help you...Best, Guy.
I haven't studied the schematics posted, so I'm just guessing. MANY different types of electronics have an internal battery to "hold" the settings while powered off. Those batteries don't last forever.
mg73.....apologies that I missed that "the battery is fine" in your original post. I still have a hunch the problem involves that "battery backup" circuitry which likely involves more than just the battery itself. But, tough to determine without proper schematics. Best of luck.....
Bri ... who needs to carefully read the thread before opening his mouth! <g>
No worries Brian.)
I had a closer looked to at the PCB around the battery
and saw that the connecting "dots" between the upper and lower layers missed solder in them(should work anyway)
but the working LYNX had and some other joints looked a bit suspicious.
Re-soldered them and bam it now works.
Sometimes you are lucky.
Its possible that the code in the eprom is becoming corrupt, eproms are known for this. Try making some copies from your good lynx and replace in the bad lynx. Happened the same in my lynx 1. Have look here Fabricating Timeline Micro Lynx transport cables I know there are some eprom images here.
Glad you chased it down! I've been around many devices that "forget" when powered off and it was always something involving the battery backup circuit. An ancient battery that "oozed" and chewed up PCB traces was commonplace.