Datavideo TBC-1000 failed, next steps?

[thestarswitcher]

Hello,

My Datavideo TBC-1000 now has finally decided to bug out. It's having difficulty with the blue channel. The standard "blue screen" is an array of dark green and dark grey lines. Initially I plugged it somewhere else which seemed to do the trick, only for it to start acting up not even 30 minutes in use (see Pic1 and Pic2 when it happened). Notice in the pictures below, the reds are bleeding into green- this never happened before.

What are the next steps to take from here? I have to tackle an important commission for a client and I won't give subpar transfers excluding this TBC.

And before any questions, I have tried different capture cards, different devices, TV's, monitors- the problem is ruled out to the TBC. I even tried to get a video from the secret-not-secret additional output/input on the inside, still the same glitchy mess.

[lordsmurf]

It probably needs a recap.
Probably.
There is always the chance errors has cascaded, unit is screwed. But caps still likely.

Contact Diopter_Doctor http://www.digitalfaq.com/forum/memb...er_doctor.html
He recently said he's fixing these.

Or if you want to DIY replace caps, that's the other option. Recent threads on where to gets caps, consensus is Digikey, Mouser, and ... forget offhand. I use Digikey.

[thestarswitcher]

I decided to plug it in again with the lid off, and casually mess around by touching the caps. Leaving the JVC blue screen on, I used this as my test.

In Img1, after tapping that capacitor, the color blue seemed to come back on certain parts of the image. After tapping one of the two circled in Img2, I started seeing green streaks.

Playing a Disney tape earlier, you know how some of them have the green FBI warning at the beginning? The majority of the green would have red artifacts on the majority of the screen. In some parts of a tape with excessive red, you'd see green artifacts. Interestingly, when I watch the tape and I see blue colors, sometimes they're fine, sometimes they're interfered by the artifacts.

Happy to hear thoughts.

[Diopter_Doctor]

Here is some up close pics of what this board had on it.

Looks like a novice/apathetic tinkerer tried to modify the board

[traal]

It's just a flesh wound!

[lordsmurf]

Quote:

Originally Posted by Diopter_Doctor

Here is some up close pics of what this board had on it.
Looks like a novice/apathetic tinkerer tried to modify the board

Ouch. I'd go so far as to call the person an idiot.

BTW, is that mold on the interior bottom case?

As I've stated before, at end of 2019, bad TBC-1000s were dumped on the market. It continued well into 2020, and was gone by 2021. Some originated in Canada, some believed to be upper north USA. Perhaps some cross-border offline auction buying going on? DataVideo has current HQ in CA, so not sure if it's leftover DataVideo junk. Was DataVideo ever in Canada, Seattle, NY, etc? Such things are not unheard of, company selling known-bad merch in pallet auction, idiot reseller buys it, sells is legit/new/etc, eBay of course.

At the same time, we had caps meeting EOL.

So the market is flooded with a mix of crap and caps damaged units. Buyer beware. It has gotten so bad, with the garbage units so common, and TBC-1000 prices now in excess of $2k, that I'm avoiding that model. My last TBC-1000 is on loan. Anther once-great item has been ruined by stupid. ATI AIW is another. Natural failure has taken out AG-1980 and JVC DD decks. Does my frustration properly come through here?

You cannot randomly buy gear anymore, condition matters more than model. But you do need to get a good model. Just understand it has to be done careful, not random, not knee-jerk, not the best "deal" that isn't a deal.

[thestarswitcher]

Hey, just a two month update into this.
So after having all the capacitors replaced and the proc-amp disabled by modification, these problems are still persistent. I'm able to confirm it has nothing to do with the power supply, as I've fed it multiple different power sources. I've scrubbed the board with 91% isopropyl alcohol, and cleaned the inside of the S-Video input (which helped very, very briefly, only for it to go back to the same problem).

What am I supposed to do here? It's a shame I spent a considerable amount of money in hopes that the problem would be fixed, and we're back at square one- and I'd also imagine it's unfair to the person who refurbished my unit because cosmetically, it's a superb job.
Just to get the "have you tried" out of the way: it's not the VCR(s), S-Video cables, capture card, capture software, macrovision, or power supply. It's solely the TBC, which is conveniently the token piece that isn't easily replaceable.

Please help.

[lordsmurf]

I left a post here just today: https://www.digitalfaq.com/forum/vcr...html#post86685
There's a guy intentionally selling a known bad unit as "untested" on eBay, and he's trying to get maximum profit from a sucker. It's a "for parts or repair" listing, too, meaning you're SOL for a return, when you learn it's a bad unit. As mentioned, this started to happen back in 2019, and scum/scam sellers are out in force again for the upcoming shopping season.

Some issues are fully irreparable, and would require now-unavailable chip replacements. But you're not privy to the on-chip software, and I doubt it's defaults. So aside from DataVideo, nobody can fix it. And they won't. In fact, they can't, those people are long ago gone, and DataVideo apparently didn't keep good records (as per my conversations with them in past years).

This chroma noise issue is not too different from AVT-8710 "attitude problems" in the final stage before unit failure. This is confirmed chip issues, root cause likely overheating that went too far. You don't know where that TBC-1000 was, and it may have been turned on 24/7/365 (stupid!) for an extended time. That's what does in the AVT-8710 units.

I wish I had a better outcome, something hopeful. But if the caps were all replacements (properly, then re-tested and confirmed good), then you're probably screwed.

TBC-1000 doesn't have proc amp. What are you referring to?

[thestarswitcher]

Quote:

Originally Posted by lordsmurf

TBC-1000 doesn't have proc amp. What are you referring to?

Meant the distribution amp, my bad.

Quote:

Originally Posted by lordsmurf

So aside from DataVideo, nobody can fix it. And they won't. In fact, they can't

Damn! Does that mean my unit is officially deadweight? What would be the other TBC-1000 equivalents that Datavideo (used to) offer? I know there's a few X000 versions.

[Diopter_Doctor]

Quote:

Originally Posted by thestarswitcher

Please help.

This is so strange. I didn't have any visual issues like this during my testing...

I actually recorded a video while testing your unit. I'll upload it to Youtube when I get time.

I used: Sony Digital handycam<(s-video)>TBC-1000<(s-video)>Sony CRT
Sheilded S-video cables, TGrant photo PSU, Home video

[traal]

Does it look the same if you feed it a composite video source?

[thestarswitcher]

Quote:

Originally Posted by Diopter_Doctor

I actually recorded a video while testing your unit. I'll upload it to Youtube when I get time.

That would be great if you can!

Quote:

Originally Posted by Diopter_Doctor

I used: Sony Digital handycam<(s-video)>TBC-1000<(s-video)>Sony CRT
Sheilded S-video cables, TGrant photo PSU, Home video

My units have been PAL S-VHS, NTSC S-VHS, NTSC DVD, and PAL Hi8. At times, when I think I've got it working, I'll see a subtle error and then gradually get worse. Notice my file "LeftTBCRightWithout" in the previous post. When the Hi8 player is on standby, I'll get a display of green and grey stripes, when it should be a perfect blue. With the NTSC VHS player, the entire thing is dark green. When plugged into an ES10, it does a "color flicker" thing between the blue screen and dark green.
On a tape with very high green or red values, you'll see green noise artifacts.
Strangely in all of this, I'm seeing no blue noise implemented- the color is always green, and we see it messing around on all R, G and B portions of the picture.

Was it tested through a capture card?

Quote:

Originally Posted by traal

Does it look the same if you feed it a composite video source?

To be honest, I can't remember what my results were, but I remember testing it. I think the problems persisted. I can't test it now since mine is modified to bypass the distribution amp. See this thread here.

EDIT (7:38pm EST): I plugged in the TBC after a week using a hard drive AC adapter, can confirm problems are still persistent. Swapped out cables for totally different ones, same problem occurs. All devices plug straight into the capture card without the TBC, clear picture.

Quote:

Originally Posted by thestarswitcher

That would be great if you can!
On a tape with very high green or red values, you'll see green noise artifacts.
Strangely in all of this, I'm seeing no blue noise implemented- the color is always green, and we see it messing around on all R, G and B portions of the picture.

Just to add to this- the noise is red on rich green picture, and anything with strong reds goes green. Anything rich blue is just dark green.

[Diopter_Doctor]

Sorry this isn't actually a test pattern. I never intended to upload this.

A few seconds of this TBC-1000 after refurb and mod.

https://www.youtube.com/watch?v=8C-_A6C1xvc

[thestarswitcher]

Update:
Look at the picture attached in this post- when I press down on that capacitor, I get strands of blue on the JVC screen. Pressing it with a pencil eraser, it doesn't do that. My theory is that human skin (conductive) is aiding with a faulty connection somewhere. I took some RCA cables I had lying around for the metal, and gently tapped the two capacitors.

Notice the path of resistors in between the two sets of 3 capacitors? I took a screwdriver and started gently rubbing the path back and forth. Picture wise, I started getting "suffocation" jumps of color and picture. So clearly, something on this part of the board wasn't making a proper connection. My guess is corrosion somewhere.

Anyway, I took an old toothbrush and squeezed a fresh lemon, and scrubbed the caps and all the resistors there. Plugged it in while it was kinda wet, picture was white. Okay, great! Something totally new. So I went back and dried the board gently tapping a paper towel, then cleaned with 91% alcohol. And.... it works! I gave it a stress test for an hour, no problems present. I'm gonna continue giving it tests throughout the week to see if it acts up.

Does anybody have any recommendations on how to keep the unit ventilated? Mine gets pretty hot after an hour of use.

[Diopter_Doctor]

That cap receives the Chroma input for S-video. So that makes sense, but didn't you say it happened with composite as well?