VT5V73 Generic 15" LCD Color NTSC Composite Video Monitor No Backlight Symptom
 

I bought a couple of used units of these No-brand generic LCD monitors to
use for video camera use. They have no brand name, and I don't know where
they were sold originally.

For my first actual fault-finding in-circuit testing use of the Blue ESR
Meter, I found a defective capacitor quickly, and restored the operation of
a LCD composite video monitor.

I had been looking at cheap, new replacement CCFL tubes and inverters for
sale on eBay, but instead, decided to finally buy a Blue ESR Meter for this
task, instead of using my usual tester, a Sencore Z-Meter.

The backlights would sometimes come on when the AC power was applied. If
they did come on, they'd shut off within a very short time.

The inverter board is a long narrow (~ 7x1") board with outputs for 2 lamps
at the ends and a 5-pin power/control signal connector near the middle.
There is only one electrolytic cap on the inverter board, so I turned on the
ESR meter and zero the test leads, and check the 100uF 25V C1 cap.. Over
Range, how cool is that?
Fast, easy, reliable confirmation of a faulty capacitor.

While I had the back panel removed, I checked the PSU electrolytics, but
found no problems. The units have an AC power cord, and the PSU supplies
only 12VDC and 5VDC to the main and audio boards, with power for the
inverter coming from the main board.

Further testing of the inverter 100uF/25V cap, with the Sencore Z-Meter
showed the following:
ESR: 220 ohms
Value: 23uF
Leakage: 10uA
Dielectric Absorption: 16% initially, increasing to over 31%

The 2 NTSC monitor units I have appear to be different versions, as one unit
has OSD menu aspect ratio choices of 4:3 and 5:4, the other one has 4:3 and
16:9.

The monitors were apparently modified to turn on when AC power is applied,
as I received them, so the on/off switch doesn't do anything.

These appear to have been manufactured in 2004 or 2005, marked as made in
Taiwan.

Inverter Label: 02B1D529 (MAYBE 02BI...) 4143015602 VER 2.06 10.06.2004


--
Cheers,
WB
..............

VT5V73 Generic 15" LCD Color NTSC Composite Video Monitor No Backlight Symptom
 

On Thu, 20 May 2010 23:04:51 -0400, "Wild_Bill"
put finger to keyboard and composed:

I bought a couple of used units of these No-brand generic LCD monitors to
use for video camera use. They have no brand name, and I don't know where
they were sold originally.

Google turns up this page:
http://www.omnivisionusa.com/desktop/15.1_FP_NTSC.html

There is a phone number at the bottom of the page.

Is there an FCC ID on the back, or is it just a compliance statement?

You may find a circuit diagram and/or user manual he
https://fjallfoss.fcc.gov/oetcf/eas/...ericSearch.cfm

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

VT5V73 Generic 15" LCD Color NTSC Composite Video Monitor No Backlight Symptom
 

Thank you Franc, you always seem to be able to find stuff that others don't,
it amazes me.

There is only a compliance statement on the back, no FCC registered numbers.

--
Cheers,
WB
..............


"Franc Zabkar" wrote in message
...

Google turns up this page:
http://www.omnivisionusa.com/desktop/15.1_FP_NTSC.html

There is a phone number at the bottom of the page.

Is there an FCC ID on the back, or is it just a compliance statement?

You may find a circuit diagram and/or user manual he
https://fjallfoss.fcc.gov/oetcf/eas/...ericSearch.cfm

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

VT5V73 Generic 15" LCD Color NTSC Composite Video Monitor No Backlight Symptom
 

BTW, the phone number listed is for an Illinois USA company

http://www.omnivisionusa.com/

--
Cheers,
WB
..............


"Franc Zabkar" wrote in message
...

There is a phone number at the bottom of the page.