Datavideo TBC-1000 makes image too bright?

[denfin]

I got a TBC-1000 and noticed it makes the image brighter for some reason.


Here is what it looks like directly on the TV.


And here is it without the TBC-1000.


And here you see it with the TBC-1000.

You can see some of the details are lost cus it's too bright. I got a Tevion ATI-600 USB and whatever I do to try adjust the contrast and brightness levels in Virtualdub it does not seem to help much, any way to fix this? And I also read somewhere you can take apart and bypass something inside the TBC-1000, would that help with this problem perhaps?

[aramkolt]

Most likely needs a recap at a minimum if that hasn't already been done. The part that people talk about bypassing is the distribution amplifier, which is the board that splits the single output into four and that could also be causing your issue. You might also find that different outputs are at different levels than each other as another recent post discussed. I did bypass the distribution amplifier on mine basically immediately, so I didn't have time to really notice that this could be the case, so you might as well check the other outputs as well.

The bypass can definitely be done, but it does require some soldering and a bit of creativity and parts for how you want to actually route things, but it's basically wiring the output from the TBC card inside directly to the outside of the box either using some of the original ports or by putting in your own.

Here's mine if you're looking for ideas:
https://www.digitalfaq.com/forum/vcr...tribution.html

Fan probably isn't needed, and simple way to go would be just soldering S-Video cables directly to the inputs and outputs as seen in some of the earlier revisions. The actual TBC board only needs 5V, so you can delete those other boards if you can give it reliable 5V power directly. I used a separate ultra low noise power supply, but that's also probably overkill.

[denfin]

Okay thanks, I see, might probably have a go at doing the mod then I think see if that improves things, or yeah maybe replace the caps or check them, have not done that so.

[lordsmurf]

Too-bright can be false anti-copy that leaks too far into the signal, and i can no longer play properly when corrected. It's not common, but also not overly uncommon.

In many cases, the wiring internal from front panel to TBC card has failed. The TBC-1000 was not the best built TBC, and most of the internals have aged poorly in the past 5-7 years. Problems started to become common in 2018-19, and it's now almost impossible to find a flawless TBC-1000 in the 2020s (unless previously refurb'd, often bypassed).

If you have re-cap skills, do it.

Just note: Never randomly re-cap TBC-1000s. Those can, and have, failed irreparably on re-cap attempts. The units are fiddly. If a unit is currently working, leave it alone. Even if A/B or C/D channels fail, still leave it alone -- only repair if both are bad (usually ghosted, or B&W).

Realize there is not a single TBC-1000, but at least 5-6 variants.

[denfin]

I tested some more now, I hooked it up via composite video instead of S-Video, and with composite the brightness was fine, so yeah there is something odd with just the S-Video output then. And I want to use S-Video of course for best quality, so want to still fix the problem. And hm I see, too bad some start to seem to start fail now... But I have replaced capacitors before on other stuff, so should not be too big of a deal if I have to, but yeah may try mod it first and see if that improves things first.

[timtape]

As a tech I checked a TBC 1000 recently. There was no color on any of the S-video outputs but fine on composite outputs. Many caps measured weak or failed. Many of these smaller caps are situated very close to one another on the PCB. It is also a double sided PCB which means replacing these caps successfully, with a reliable connection on the top side, may be challenging.

Fortunately these caps are the older through-hole type which generally last well but the fact they dont seem to have lasted well in this unit suggests they have been under stress. With Aramkolt my guess is the unit runs hotter than acceptable, leading to overheated electrolytics.

If I owned one I would take steps to improve the cooling situation before putting the unit in back into service after doing all that work to replace the faulty caps. Otherwise those new caps would probably also have a shortened service life.

[denfin]

Okay, will keep that in mind if I need to replace any of them that connection on the top may be important too! And I see, may put a fan inside also, think I have a small one laying around, and hook it up with a separate power brick, thanks for the tips!

I been messing around with it now a bit and taken it apart, and found some RCA and S-Video female sockets I could use and this is how I plan to do and my take on the mod, and make it kinda simple i thought, hope this look okay? I also found a ferrite cylinder I could use too, so both input and output will have one. And I swapped the input and output around, cus I perfer to have the output on the front, guess that would work connecting everything like this? Unless I'm missing something.

[aramkolt]

Kind of up to you, but that small power board there only takes the input voltage and reduces it to 5VDC, so if it were, me, I'd delete it and just power the whole thing with 5VDC. the original distribution amplifier board also has a diode that drops the input power by about 0.7-1V and I believe that is there more for reverse power application protection, but as long as you are sure everything is correct, you don't really need it. I also can't remember if the original distribution amplifier board has more like 9V-10V going into the small power sub board there instead of 12V like you currently have it wired. Making it a 5V system just gets rid of all that guesswork. The only thing that won't work is the power LED, but you can experiment with different lower value resistors on the little LED board to get it working.

You also have your inputs and outputs labeled backwards in the picture, but that doesn't really affect anything unless you try to test it that way - you just won't get any image output through input plugs.

[denfin]

Okay might go for 5v instead if I happen to have some spare 5V power supply or a USB one laying around, so I just hook up 5V here?


Or if I still use the same power supply, what diode might be needed, and where do I put it and in what direction?

And I thought of solder the front panel LED here and remove the LED that already sits there directly on the main PCB here, would that work?


And ah yes, it's reversed cus it kinda makes more sense for me i feel how I have the TBC placed next to my TV and have the output cable routed to the front anyway to my capture laptop, so thought this might be better! And I will probably make some new "Input" and "output" labels and place over the originals.

[denfin]

I managed to mod it now and with 5V, maybe not super pretty but it went well! But yeah, sadly I still have the same problem that the image is too bright, so the fault was not in the amplifier board then What capacitors may I first want to try replace? The big ones near the output I circled around perhaps?

[aramkolt]

You really want to replace all of the capacitors on the main board. They used very poor quality caps for all of them. CapXcon if memory serves. I like anything from Panasonic, Nichicon, ChemiCon, or Rubycon as far as replacements go. I get everything from Mouser or Digikey to ensure authenticity as fakes do exist. Would strongly avoid anything made by Elna even though they are a Japanese company.

[lordsmurf]

I would not necessarily state "poor quality", but rather that the unit was never intended to last 20-30 years in use. Capacitors are not the only part of TBCs that are commonly failing now.