TBC-1000 tinting issue, easy fix? Where to repair?

[22west]

Hi All,

There have been a couple of small threads similar to this but not exactly the same so I am starting a new thread.

I am 95% sure there is an issue with my TBC-1000. I would like to know if anyone has had this problem and went inside the unit and fixed it or if anyone knows of a repair shop who fixes these units.

I have created some screen captures to show the issue. See attached image "TBC-1000 TINTING ISSUE.jpg"

In general :

Source (S9911U) to monitor - no tinting.
Source (S9911U) through TBC via composite (RCA) in and composite (RCA) out : no-tinting
Source (S9911U) through TBC via s-video in and s-video out : tinting.
Source (S9911U) through TBC via s-video in and composite RCA out : tinting

This is not a capture issue as I am seeing the issue directly on my broadcast monitor.
This is not a cable issue because I have swapped out different cables several times for each setup.
I have also varied the source (player and tape).

The unit was like this when I first got it (brand new from Datavideo). I ignored the issue because I decided to just do composite pass throughs, but now I want to pass through the unit with s-video.

Please help!

Thanks,
22west

[lordsmurf]

I don't see any tinting. I see luma value correction (AGC). Correcting timebase can have this affect. It can be a tape, or a workflow interaction with the VCR. Very often, this is tape-based interaction. This is precisely why every workflow here has both DataVideo and Cypress TBCs (both this, and other potential interactions). I see this quite often.

Realize that "a tape" may also refer to ALL tapes from a certain camera, made on a certain VCR, etc. You must wildly diverse tape for a testing bed.

Without seeing more samples, and especially test patterns, I wouldn't judge the correction to be wrong, nor the unit to be faulty. The "straight from VCR" could actually be wrong.

In terms of deck lineage, the 9911 is also suspect. Another VCR must be testing for thorough troubleshooting, process of elimination.

[22west]

Thanks LS for the super quick reply.
Why doesnt the composite pass through do this too? It's all the same hardware. . .

-- merged --

Hmmm . . . I am starting to get what you are saying about luma. The s-video cable separates the luma and the composite doesn't . . . Maybe this is why the composite cable doesnt notice the luma correction so much.

[lordsmurf]

I had missed where you stated s-video and composite were behaving differently. Interesting. Odd.

However, realize s-video is "separated video" (not "super video", or some such), with luma/Y and chroma/Cr+Cb carried on separate wires. Composite is YCrCb composited (mashed together) on the same wire, and has consequences such as crosstalk (dot crawl). So what I said is still not nullified, timebase correction can very definitely act differently on output, though not quite as often. This is why, less than 1% of the time, composite is actually better than s-video for transferring a tape. But that's not this situation.

Really, I have no idea. Just postulating some hypotheses for you.

The TBC being defective is not outside of possibility. Had this been an AG-1980P VCR, the immediate answer would have been bad caps, as I've see this exact error on that VCR, and that is the issue. DataVideo rarely has caps issues, and I've never read about or seen this specific error (at least that I can recall, realize I'm now just a couple years away from having done hobby/pro video for 30 years! yikes!). The DataVideo may not even be designed in a way that caps would have any affect on luma/AGC, good or bad. ehbowen had somebody in Houston look at a TBC-1000, but ultimately his was traced to an irreparable issue. Perhaps yours is not that bad off? TGrant, deter, and basically anybody I've ever asked won't touch a DataVideo TBC, either due to lack of knowledge or lack of willingness. I have some level of knowledge to clean, rebuild, modify the DataVideos, but no idea on this one. jwillis has been a tinkerer in recent years, and quite successful at various teardowns and repairs (especially at his valued input on ISOBuster!), but I don't want to volunteer him for any projects (though if he does, I have some DataVideo docs to share).

I wish I had more for you.

We do need to see lots more test images, maybe some compressed videos to look for active AGC. I generally dislike test patterns (VCR testing especially), but for TBCs it is required.

The TBC-1000 was long-lived, and had at least 5 different major revisions, very obvious internal redesigns. And probably multiple sub-revisions, mid-production changes due to parts availability. One of the revisions would pick up "vertical lines" from JVC VCR menus. Softness sometimes happened, but again it was usually tape/workflow interaction, and also "random" (likely because some revisions/sub-revisions had it, or at least more more susceptible to it, and some did not). There were also PAL-first and NTSC-first models, with no relation to the green "NTSC" or yellow "PAL" stickers on the unit, though both worked with both PAL and NTSC.

[22west]

I would like to close the loop on this thread:

I found out that the input board in the TBC-1000 was not properly mounted and was loose - "spongy" to be exact. It turns out that the plastic bosses used to mount the board inside the housing were cracked and subsequently glued back in place by "someone". I guess the glue broke down over time. This was a surprise to me since I bought this unit new many years ago from B&H. Anyway, the loose board was not allowing the s-video pins on the cable connector to be fully inserted to make good contact - no matter how hard I pushed.

After removing the board and remounting it properly all has been good. No tinting issues. I actually leave the cable connected in the front at all times now.

Regards,
22west

[latreche34]

Interesting on how B&H would sell a previously owned and broken unit as brand new, Never bought from them, never trusted them, and their prices are not in my range anyway, I always get my stuff at 1/10th price of B&H.

[lordsmurf]

The front panel is a weak point of the model, due to plastic. There are several ways to fix this, but attempting to glue the screw holes is the 1st step. Others get more involved. I'm not aware of this being a USA HQ warranty fix (manufactured in Asia, small issues fixed local), but it's not outside possibility. B&H may have also repaired it, but less likely. Customer return very likely, but not only potential reason.

B&H pissed me off too many times over the years. I use Adorama, Unique Photo, and Amazon. But the only way to get "1/10th" prices is to buy used, probably very used. They do have some of the best prices around, but others are tied, or a few bucks more/less (not much). Quite a few price match, too. For example, B&H had a great sale on Cyber Monday this past year, but I got a price match elsewhere (and with no tax, so 9% cheaper too!).