DataVideo TBC-1000 video board glitching?

[lordsmurf]

This has nothing to do with this unit, but...

I've seen low voltage errors before, but could never corroborate it with anybody else. I knew it!

DataVideo rated this unit 12V 1.2A, yet shipped OEM PSU 800mA at one point. Those 800mA units have likely all failed by now. I've not seen any 800mA units for several years now.

Although many claim that "amps don't matter", those can if too low or too high. 800mA is only 66% of the 1200mA required current, regardless if both rated 12V. In actuality, volts will drop as a result of underamperage. The outcome is not enough power, the unit tries to pull more, heat builds, permanent power problems, failures. Inversely, PSUs rated for higher amps, 3A to 5A (or more), are often built to natively feed the item more amps than desired, also not good.

Back around 2017, I had a TBC-1000 brick on me, while trying to confirm power requirements, and understand why DataVideo would have provided 800mA OEM supplies. It's why I started to trash anything less than 1.2A, and only use 1.5A to 2A adapters from quality brands (usually APD).

I'm actually actively avoiding DataVideo TBC-1000 now, as of fall this year (so a recent decision), too many potential issues. The reports of failures keep rolling in now. Even the TBC-3000 has me spooked a bit. The metal Cypress are holding up better after 20 years, and a few certain rarer others.

Back to your unit...

I think a primary issue with underamperage (thus undervoltage) is heat-based component damage. I know, more amps cause heat, but components not getting proper amps can also overheat. The unit you have was subjected to one of the hottest summers on record. It's my strong suspicion that heat inside shipping vehicles pushed it over the edge.

It's probably no coincidence that 2023 had the highest number of gear failures I've ever seen, both my acquisitions for the marketplace, and my own personal gear. Thousands of dollars lost. It sucks. The heat this year was oppressive and damaging.

ehbowen on this forum may still have his semi-fubar irreparable DataVideo TBC-1000 unit. If I were you, I'd try to acquire it from him, and then frankenstein a new unit.

[Diopter_Doctor]

After frankensteining boards from another TBC-1000 unit, I discovered the root cause of the power issue. The main power switch had high impedance and was loading the 12V from the PSU. After replacing the 8V voltage regulator and checking the diode, which was fine, the voltage still ran low on that specific frame/chassis. After removing the hot glue to check the switch, it read 2 ohms.

Again, the low voltage is what messed with the video board. Since the switch is attached to the frame, it doesn't get into my test bench... but now we know it was something so simple yet devastating.

Well, the member has one working unit now and one I'm sure he will be selling for parts/partly working in the future.

[lordsmurf]

Quote:

Originally Posted by Diopter_Doctor

After frankensteining boards from another TBC-1000 unit, I discovered the root cause of the power issue. The main power switch had high impedance and was loading the 12V from the PSU. After replacing the 8V voltage regulator and checking the diode, which was fine, the voltage still ran low on that specific frame/chassis. After removing the hot glue to check the switch, it read 2 ohms.

Again, the low voltage is what messed with the video board. Since the switch is attached to the frame, it doesn't get into my test bench... but now we know it was something so simple yet devastating.

Well, the member has one working unit now and one I'm sure he will be selling for parts/partly working in the future.

So the little plastic rocket power switch was the root cause? If that what you're referrring to?

[Diopter_Doctor]

Yes! Through me for a loop.

[lordsmurf]

SOB. You know, I ran into that about a year ago with a DVK. I had to buy a 5-pack of those rockers. In the DVK instance, it was failed, so it was easy to isolate quickly.

You spent how many hours on this, and how much $ on parts?

The new rocker switch is maybe $2 at most. Are you able to create another TBC-1000 now?

The rockers can be damaged in mulitple ways:
- jamming in the PSU cord
- heat or cold, as stated before
- excess drop damage during shipping, even if well packed and padded

So the usual suspects: user error, climate victim, shipping goon victim.

[latreche34]

This is why it's important to check your voltages first before attempting to do any repair starting from the source and going down stream including before and after switch, A 2Ω resistance would definitely give you a voltage difference across the switch which it shouldn't, I though you have done this step already.

[lordsmurf]

Quote:

Originally Posted by latreche34

This is why it's important to check your voltages first before attempting to do any repair starting from the source and going down stream including before and after switch, A 2Ω resistance would definitely give you a voltage difference across the switch which it shouldn't, I though you have done this step already.

Live and learn.

Honestly, I would have never suspected that either. I probably would have caught it earlier in the initial tracing, but would have been equally surprised. Of all the things to fail .... it's that?

[Diopter_Doctor]

Quote:

Originally Posted by lordsmurf

Are you able to create another TBC-1000 now?

The member had an old spare TBC that we used the best parts out of each to make one working and one semi-functional. The video board is still damaged like we said at the beginning of the thread.

Quote:

Originally Posted by lordsmurf

The rockers can be damaged in multiple ways:
- jamming in the PSU cord
- heat or cold, as stated before
- excess drop damage during shipping, even if well packed and padded

The metal on the contacts can also have build-up from arcs which increases the impedance. I haven't cut it apart yet, but I bet that's what happened here.

Quote:

Originally Posted by latreche34

...I though you have done this step already.

My method is taking each board out and testing it individually to isolate the issue. I start with the video board since that's the brain of the unit. Making a new PCB for power is doable, replacing the video board isn't without cannabilzing another unit. If you can't fix the video board, the rest doesn't matter to the customer and any further refurb is likely a waste of time, hence why I took so much time to even get to the amp board.

The switch is the only thing attached to the chassis so it doesn't come with the amp board when removed. After replacing the 8V regulator, it worked fine on the test bench. After putting another amp board (I received an extra TBC later on) back in the same chassis, I noticed the voltage was still not 8V. It was better, but still not 8V. That's when I figured out to check the switch.

The video board did improve with the new SMD resistors (the color glitching resolved), but the board obviously had multi-point failures when I received it. So discovering what caused the problem doesn't change the ultimate solutions or outcome at all, I just wanted to post for anyone in the future.

[lordsmurf]

Quote:

Originally Posted by Diopter_Doctor

I just wanted to post for anyone in the future.

Good work.