Thank you, community, for sleuthing the DPO4xxx 'scopes. I'm thinking (hoping) my DPO4104 might also have bad RAM. This scope also has a "stuck in splash screen" fault. Before I knew about the debug serial port, I tried updating firmware via a USB stick. The update started, but got stuck somewhere. Now that I have a debug port dump, I can see where it fails, but I don't "speak uBoot", so I'm not sure what to make of it.
Erasing and flashing flash pages goes along just fine, until it attempts a file mount. A snapshot of the key part of the dump follows:
(boot & update messages)
...
Erasing 128 Kibyte @ 160000 -- 91 % complete.
- Writing to flash; this may take a while...
Finished updating backup kernel.
Updating filesystem... DO NOT TURN OFF THE SYSTEM!!!!
Extracting the contents of /usr/local/perm...
- Erasing flash... this may take a while.
Erasing 128 Kibyte @ 1de0000 -- 99 % complete.
mount: Mounting /dev/mtdblock7 on /mnt/rootfs failed: Invalid argument
- Writing to flash; this may take a while...
tar: Cannot create directory `./usr/local': No space left on device
tar: Cannot create directory `./usr/local': No space left on device
...
(repeat a bunch of times)
...
tar: Cannot create directory `./usr/local/': No space left on device
tar: ./usr/local/bin/scopeApp.ppcep: No such file or directory
An error occured while updating the root filesystem!
(the end)
Looks like tar was uncompressing a file, but had nowhere to go.
Best case scenario, I replace some RAM and all is good. Worst case -- it's bricked.
-Mark