Regarding eBay, test the AG1980 thoroughly the day it arrives on your doorstep. If there's the slightest thing wrong with it, contact the seller to negotiate a lower price or a total refund. Rule of thumb, mechanical problems are easy to fix, video problems require a total rebuild (expensive). Use your judgement on whether the AG1980 in question is worth a repair or not. BTW if the seller balks or is unhelpful, file a complaint in the eBay dispute console immediately to ensure eBay freezes your money in the sellers account pending a forced refund.
Regarding DIY replacement of AG1980 caps, my advice is "don't try it." The AG1980 was the most convoluted, over-engineered-but-underbaked VCR Panasonic ever sold (and that includes super-high-end pro decks). When it works perfectly, it works perfectly, when it flakes electronically, there is no such thing as an "easy" or "inexpensive" repair. There are countless caps in the unit, and they fail in a cascade with one board contaminating another. Video issues invariably require replacing groups of tiny surface-mount caps, which is difficult under typical DIY circumstances. The 1980 circuit topology is notorious for "whack-a-mole" tendencies: you replace three caps that test bad, and then another six go out, you replace those six, only to find another twelve go out. A durable repair job that guarantees at least a couple years of reliable operation typically involves replacement of some 30+ caps.
For a brief overview on repairs, see this link
. For extensive discussion of the AG1980, see this AVS thread
. The two best-known repair specialists for the AG1980 are JOTS Electronics
in Texas and Southern Advantage
in North Carolina.
The perversity of used VCRs is that normal inexpensive typical 4-head HiFi models have small circuit boards that almost never go bad, simple power supplies that never go bad, and fairly reliable mechanics. Since you can buy them anywhere for $25, if they break you just trash them and hit Craig's List for another. The drawback is their video playback is mediocre at worst and just OK at best. A Panasonic AG1980, or JVC SVHS with TBC/DNR, or JVC or Mitsubishi DVHS with TBC/DNR, can offer significantly better playback. BUT, the AG1980 and old JVC SVHS models are fragile and costly to repair, while the DVHS models are newer and usually in perfect condition their purchase price can be up to $500. Used
, mind you. There's really no middle ground: you pay thru the nose for a fancy used VCR and cope with the headaches, or settle for a traditional good-but-cheap VCR to get reliability at the sacrifice of optimum playback quality. Its a tough call money-wise.