The whole thing about TBC's is they (stop).. not prevent, not sort of.. maybe lessen frame drops.. they (STOP) frame drops.
A TBC captures the video signal, makes a whole video frame and then puts that on its outputs in a pristine "digital" form but as a fresh analog signal.. there are no drop outs or missing frames. It will insert fake frames if it has too.. but its mission in life is to output a "perfect" signal.. optimal for video capture by anything downstream.
The ES10 has to do the same thing "before" it could burn to a DVD disc.. but its doing it (all the time) from Input to Output.. so that is why its one of the "special" DVD recorders that can be used while its not burning a DVD for signal preconditioning (pass-thru).
That it has roll or signal issues and can't lock on to a signal means either the signal is just too poor to be recovered.. or the Digitizer has low voltage or not enough electrical power from its Power supply and its sort of behaving like a drunk driver on a freeway half awake. Its most probably a Power supply with a few caps that are long gone and more are in the process of dying.
A better VCR, better tape, anything that improves the signal before it gets to the Input of the ES10 are always good things.. but the ES10 was designed to grab signal from the worst scummy VCR found in a ditch somewhere and turn it into a wonderful work of art.
If the ES10 can't do it.. its probable nothing else can.
And if you have to improve the signal to the ES10 before it locks on.. that says something is very wrong with it indeed.
I would say though.. as far as the design of all the recorders that came after it.. its immensely easy to troubleshoot and repair. There aren't a lot of parts to figure out where the problem is. Its modular, the Mainboard is jumpered to the Power supply. The Mainboard is jumpered to the Digitizer. The Digitizer is jumpered to the DVD burner. And there's tons of open space in the box. The case was probably a prototype for much denser stuffed designs to come.. so in some ways it was "overbuilt". Its just that its Power supply was definitely not designed to go for more than 3 years.
Video capture with a PC pretty much requires an old retro PC running XP, you can do it with Windows 7.. barely.. the "good" capture devices and cards are getting hard to get. Almost forget the Mac platform.. Apple stomped all over consumer video capture back in 2010 and here in 2019 they have outlawed it and will be removing Quicktime at the end of 2019.
I do persevere in researching capture cards, dongles and "methods" here in 2019 but I'm not ready to publish any recommendations.
About the best thing since Feb of 2019 is find a Panasonic DVD recorder with a Hard drive on the Isobuster "list" of supported DVRs. Isobuster is a program that will run on a PC, Mac or Linux and will "Read" recordings off the hard drive of a "supported" recorder and let you copy them direct to a PC folder. - You do have to remove the hard drive from the recorder for "dumping" these to your PC.. its not totally hands-free.. but it lets you record at the best speeds and doesn't require a working DVD burner or to chop up a video length so that it fits on a DVD.. Isobuster lets you copy it as is.. entire length.. in one go.
So you can use a Panasonic DVD recorder to capture video from a VCR for several hundred hours till its nearly full, pull the hard drive, connect it to an IDE or SATA to USB adapter to a PC, Mac, Linux machine.. and copy everything to the PC.
After its on the PC you can use whatever video editor you want to read the files and edit them down, chop them up.. and burn to DVD or Blu-ray.
DVD-R just had a 'death in the family' by the way.. Verbatim just gave up the ghost and will no longer be making DVD-R media.. it was one of the last good quality DVD-R media makers.. we're down to one company now and the quality has been questionable in the past.
I've tested about 52+ DVRs with Isobuster and made a few videos on youtube for the Pioneers.. you can find the videos here: Pioneer DVRs
I really really like the Pioneers DVRs (they are Top knotch) but command a premium price even used.
The Toshibas DVRs are legendary and now that you don't have to use their failure prone DVD burners.. they elicit pure 'bliss' when used.. but they are not for everyone. Certain Toshiba models lacked IRE controls until the RD-XS34 and RD-XS35 models came along... so excellent for Japan or Europe using NTSC.. not so much for everyone else. I could write a lot about how flexible their hard drives are, switchable between models, not picky about drive brands.. just very flexible.
The Panasonics I've tested the most models.. and learned a lot about doing things you can't do on other models.
The Magnavoxes are "great" even in 2019 for their ATSC over the air tuners.. but they cost a fortune used, and the last series (800 models) have not been added to support. Only the 2100 and 500 series are currently supported.