I own two DMR-ES30V (2005) models, one purchased new and the other refurbished by Panasonic. Both have served me well.
I also own four DMR-ES35V and four DMR-ES15 models (from the 2006 model year). As some of these 2006 models were purchased used, some with stated or unstated defects, I purchased two more DMR-ES35V models "as-is" for parts swapping to keep the others running.
So far I have replaced power supply capacitors in three DMR-ES15 models. These capacitors were special ordered through a local electronic parts store. The replacement capacitors are of the same specification as those used by Panasonic but from a different manufacturer. All three of those ES15 machines tested out OK after the capacitor replacement and two were put back into service, one for a month and the other for six months. Two of these ES15 models have recently experienced failures, perhaps related (or not related) to capacitor failure. The third was recently found to be "dead." I expect to more fully evaluate these ES15 models in the near future. Perhaps I may find that the replacement capacitors I used were of substandard quality.
Three of my DMR-ES35V combo recorders have been set aside for capacitor replacement for several months now. These particular models have had very heavy use, averaging more than 3,000 recording hours per machine while in my service.
I have also swapped out defective DVD drives (after first cleaning the hub/spindles to determine if these drives had experienced a failure due to dust or other residue). In one instance a still-good DVD drive in a ES35 parts machine had the DVD drive ribbon cable very tightly lodged in the controller circuit board's receptacle. The force required to remove the ribbon cable damaged one of the ribbon cable's contacts. I evenly trimmed back the ribbon cable contact strip, as you did, to provide a uniform contact area and swapped that DVD drive into the other machine, an ES15. That repair was successful. The machine functioned for six and a half months (until 8/4/08) without a problem. That machine and the two others that have recently been found with problems, all ES15 models, have been set aside for further evaluation.
Since electronics is not my field perhaps I am merely reassuring you that the ribbon cable repair is probably not the problem with your DMR-ES30V.
I have observed that Panasonic's proprietary parts usually may not be swapped from one model year to another model year. If your DMR-ES30V's problem(s) are due to a failure of proprietary parts, perhaps the best advice I may give is to find a DMR-ES30V parts machine. If they may be found at all, they should be inexpensive. My ES35 parts machines were found on eBay.
Both DMR-ES35V parts machines I purchased were selected because their defects were of little or no concern to me. One had a bad tuner; the other had display and some other functionality problems. Both had good DVD drives, now residing in ES15 machines, and several other parts that have been swapped into other ES35 machines.
Another 2005 combo recorder, the DMR-ES40V, might appear to be similar to the DMR-ES30V but it may not use the same CPU (SOC) controller circuit board. All my 2006 models use the same CPU controller circuit board (VEP79132) but may need model-specific firmware if swapped to another model. That same situation may not be the case for the corresponding parts between a DMR-ES30V and a DMR-ES40V. (I own one DMR-ES40V combo recorder, a machine with many bugs and design flaws. I have never opened it's case. Since 12/05 is has seen little use as a recorder--355 recording hours since new. In the last year this machine has been the VHS/DVD player on the family TV.)
The DMR-ES30V is an outstanding combo recorder. I hope that you may resolve its problem(s) and return it to full functionality.