JVC HR-S7800U Constantly Ejects Tape

[pumapuma]

Hello,

I have newly acquired a JVC HR-S7800U for a little tape conversion project. However unfortunately I am having issues with the unit as it constantly ejects tapes. I am quite confident that it was working well before it was shipped to me. The interior of the unit is in immaculate shape. I feel as though something is out of whack and just needs to be put back to the correct position. When I received the machine it was shipped with a tape inside the unit and I immediately tried playing it out of the box (stupid idea, I know). The tape got tangled when I ejected and I needed to open the cover to unhook the tape.

Below are a couple of videos that show what is going on from different angles.

https://youtu.be/3R63jrJ_tvI
https://youtu.be/W57UaHo6SUI

I'm really hoping that there is some JVC VCR guru out there that can help point me in the right direction to get this fixed. It a good unit and I'm trying to avoid putting it in the mail again. Let me know if there are other angles, pictures, or voltage measurements that you need and I'll do my best.

Thanks!

[JVRaines]

It looks like something is preventing the cassette from fully seating in the compartment. This could be a foreign object or a misaligned part. Less likely, one or more load sensors are not working and the micro panics. Do you see the "cassette loaded" icon on the front panel at any point during the process? It could also be a broken tooth on one of the load gears.

With the power off and the VCR unplugged from the AC outlet, try turning the load motor shaft by hand. Turn only the motor shaft; don't try to turn any gears or pulleys. See if you can get the cassette to load fully and if not, go slowly back and forth until you find out what's blocked or not lined up.

See also this section of the venerable old Repair FAQ that may be of help.

[orsetto]

A good place to start for JVC repair info is http://www.digitalfaq.com/forum/vcr-repair/.

From the looks of it, something is impeding the loader from latching down, so a sensor is immediately triggering eject to avoid the tape tangling up inside. There is not the slightest movement from any of the tape loading pins: you're triggering some kind of preventative cutoff. Repair could be as simple as snapping a gear back in place, or as complicated as replacing a sensor with a bad cold solder joint that broke during shipping.

This series of JVC is twitchy to begin with, even when working well. Shipping often knocks something out of alignment: once that happens, your best bet is an experienced VCR tech. Any number of websites will give you tips or instructions on how to DIY repair loading problems, but with JVCs one is much better off paying a pro who has the proper tools and gauges. A blindfolded four year old with a Fisher-Price toy screwdriver can sometimes fix a basic Panasonic vcr, but high-end JVCs require professional attention.

BTW, appearance means nothing: I've seen far more problems with "like new" VCRs than beaters that look like they've been used at construction sites. Older models that look "new" can suffer from sitting unused for long periods, esp the top-line JVCs and Panasonics. When it comes to VCRs, reliability is inverse to price: the more high-end units are the most trouble-prone. Plain-vanilla basic vcrs can sit in a garage for five years, be sold on eBay, shipped cross country, and arrive in perfect working order.

[schematic2]

have you tried it with the cover on? ambient light can fool with the optical sensors....

[pumapuma]

have you tried it with the cover on? ambient light can fool with the optical sensors....

I feel like such an idiot. I put the cover back on and it accepts the tape, no problem.

Orsetto, it looks like you're right about alignment getting knocked off during shipment as it looks pretty snowy. I'm not sure what the best bet is to tackle that.

Thanks for your replies.

[JVRaines]

Snowy picture could be mistracking — try the manual tracking adjustment — or dirty video head.

[pumapuma]

Snowy picture could be mistracking — try the manual tracking adjustment — or dirty video head.

Definitely not a dirty head as I have already cleaned it. I tried manual tracking, however I could never seem to get it any better than it was displaying on auto. Also, have tried a number of different tapes and they appear to be similarly affected.

[JVRaines]

If the tapes are from different sources, then you likely have a problem with the VCR. Can you try a known good commercial tape? That would be the clincher.

A number of people here have found that a basic Panasonic in good condition handles marginal tapes better than JVC.

[orsetto]

Snowy picture could be mistracking — try the manual tracking adjustment — or dirty video head.

Definitely not a dirty head as I have already cleaned it. I tried manual tracking, however I could never seem to get it any better than it was displaying on auto. Also, have tried a number of different tapes and they appear to be similarly affected.

This usually means one of three things: the heads have a stubborn coating of grime that resists standard cleaning, the heads have been damaged by previous cleaning attempts, or there is an electrical problem involving the head drum (bad grounding, blown part or intermittent connection). Resistant dirt will create random streak patterns, damaged heads will look similar but more severe, electrical issues appear somewhat different (less streak-y and more snow-y, often in repeating patterns).

At this point the unit likely needs professional service. If you're very lucky, it just needs a careful cleaning with pro-level solvents and a deft touch with chamois swabs (or realignment of the tracking system). But if the heads suffered physical or electrical damage, the VCR might be a doorstop. Replacement head assemblies are hard to come by nowadays, the parts + repair cost could easily exceed $200. Whether such repair is worthwhile is a tough call: if you trust your tech it may be a better investment than trying again with yet another used VCR. A repaired bird in the hand is better than a pig in a poke.

[lordsmurf]

This thread started off sounding like this common JVC issue:
http://www.digitalfaq.com/forum/vcr-repair/4425-jvc-s7600am-keeps.html

All snow doesn't sound like the heads at all.

[orsetto]

Since tapes load normally with the cover on, and you aren't experiencing any other dysfunction aside from a snowy picture, I think you're out of DIY options, pumapuma. Depending on the VCR make/model and previous history, a picture loaded with snow can be caused by tracking misalignment, head damage, and/or electrical vagaries in the chassis. Shipping can aggravate borderline issues, such as chassis/board grounding connection or mechanical alignment. It is easy to get enthralled by breathless forum descriptions of how "amazing" and "necessary" these VCRs are for digital tape transfer, and overlook the warnings that initial purchase price is only half the cost. To get the playback quality these machines are famous for, you often need to pay for a professional overhaul- fresh off eBay, they're seldom in perfect condition.

Ugh- I forgot about that gear failure possibility, LS. Good ole Dynamic Drum: the pointless "feature" nobody asked for or truly needed, served only to reduce reliability and complicate repairs on the models afflicted with it. Much like German camera mfrs of the 1950s, Japan tended to over-think some of their high-end VCR designs. I always found Dynamic Drum "noiseless search" more creepy novelty than useful tool. By 1987 the "search lines" in most 4-head VCRs were nearly invisible anyway: its a mystery why the hell any mfr thought auto-tilting heads with fragile convoluted geartrains (for the sole purpose of reducing speed-search noise from 8% to 0%) would have huge sales appeal.

[pumapuma]

This was a bit weird to me, but I left it playing last night and when I came back to it, I noticed that the picture was dramatically better. The 'snowy' lines were not nearly as noticeable and they were now just the occasional streak. I went back to cleaning the head and let it play another tape or two and now it is fixed! There must have been something blocking one of the heads, possibly from sitting inactive for so long. I think it's at the point now where I won't need to even take it in for alignment.

Playback on an old commercial tape:
https://youtu.be/rcs-gofE2Lw