Leaving VCR TBC gear on UPS?
 

TGrant told me that he leaves his Pannasonic 1980s on junction boxes and turns them off when they are not in use. Should I just leave all my gear plugged into my UPS and plugged in and turned on?

AG-1980P is a PITA machine with power.
- Caps can easily blow when plugged/unplugged.
- But then caps can easily blow if left on, and power fails while on the UPS.

The best advice is to only turn off
- when not planned to be used for 2 weeks more
- when power outage has sapped UPS battery less than 50%, or when you won't be around during a bad weather forecast

It's really about mitigating problems, and realizing it'll never be 100% safe.

The is why owning a Panasonic AG-1980P is a money pit. So touchy, can break at any time, seemingly for no reason.

AG1980's leave a fair amount of their electronics "on" even when in standby mode. The front timer board is particularly known for having a couple caps run quite hot, even in standby - like we're talking 65 degrees C continuously on caps that are rated for 85C temp max. I always replace those with 105C caps whether they are bad or not, but I wouldn't want to chance having early cap failures needlessly there or elsewhere. Pretty much is a given that the SMT caps on the TBC board, so if those haven't been replaced, you can expect those to fail the rest of the way. After that and the deck being appropriately lubed and making sure the pinch roller is in good shape, they have been pretty reliable for me.

Not to OT the thread, but noting this is adjacent here...

If you know about AG-1980, then what causes the noise emitted from the PSU? It's not the PSU itself, as you can exchange the module for a good/re-capped one from another AG-1980, and it still happens on the offending machine. The PSU is seemingly the terminal location for something upstream.

- I asked TGrant this years ago, and got a non-answer.
- I asked Deter this repeatedly in recent years, and got a non-answer -- though with the well-intended and obvious answer that you just need to replace every cap anyway. And nothing that TGrant did not do this, he just replaced bad caps, which is why his "refurb" units re-failed at the next failed cap (much to the extreme irritation of us previous buyers).

I have unit right now, that works perfectly, aside from very loud high-pitched "CHIRP! CHIRP! CHIRP!" that makes it unusable. I sent it to Deter for a refurb, and should be getting it back soon.

It's the bad front-board caps that causes 95% of the squealing. I have experienced what you've described where you can hear it from 30 feet away on one unit in particular. The noise itself comes from the power supply area (it's actually the transformer resonating I think), but it's caused by some sort of harmonic resonance when there's caps that have "gone open" in the front LCD board which is basically caused by the electrolyte boiling off over time as some of those caps are 65 degrees celsius even with the unit just in standby/plugged in, and they're only rated for 85C probably for 1000 hours which they've well exceeded after this many years if they've been plugged into power for any length of time. Replacing the power supply caps will reduce the squealing a bit further (mine are dead silent as I recap the power supplies for good measure even though most of those caps will usually test fine).

They probably aren't sharing the answer because it's a relatively simple fix that requires almost no disassembly (compared to getting at the TBC card (which should also be fully recapped if it hasn't for a proper refurb). I mean, I get it, they want people to use their services.

There's plenty of people who would rather pay to have something done right (then chance damaging something, or spending a lot of time retiming the tape mechanism for the first time) and I figure it builds more trust to tell people what you do for common issues, but that's just me.

I can remember thinking the AG1980's K-Mechanism was the one of the most difficult "puzzles" to get timed correctly the first time I did it and it must have taken 4 hours straight to figure it out. These days I can re-time the mechanism in 5 minutes with the experience I've had and not have to disassemble the whole unit 5 times for each attempt "hoping" it is timed correctly.

I plan to offer my refurbishing services eventually at lower prices than Deter and TGrant because I enjoy doing it and I've purchased the parts in bulk, though I haven't quite figured out how I'd handle a situation where parts are bad that can't be replaced (like microprocessors, etc). Time spent and capacitors replaced are kind of lost at that point though.