Nuova Marea MV-1501 (Unicont) Blink and off at power on

[sententia]

Hello everyone,

I have this Nuova Marea display, which i found is manufactured by Unicont, that is a marine LCD. It can be supplied with 10-36VDC.

The problem is that when power is supplied to it it blinks and then is dead. The output of the DC-DC converters is 11.6V and stays there when the monitor look dead, so i doubt it is that the problem. I also tried to supply 12V straight to the cables but no go.

I tested one filter capacitor on the inverter board which is a HITANO ECR 330uf 50V and measures OK.

Any ideas of what to check/measure next?

Do you think the problem might be with the lamp connection on the lamp side?

A lot of gables are glued so i am trying to be as less invasive as possible.

Any help greatly appreciated!
Thanks!

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

some more pictures of the bottom side of the inverter.

[stj]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

try it with the invertor unplugged.

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Hmmm .... unplugging the inverter does not make any difference. Then power light does not blink... do you think i should check the logic circuit?

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Hello,
I have taken some more pieces apart from the monitor and have done some more testing.

By the way the LCD panel is a LG Philips ....

I have replaced some capacitors from the logic pcb as the big 220uf 25V Chengx cap that measured around 195uf and 4ohms ESR but didn't seem to help. That logic board has a lot more smaller cap also from Chengx that make me worry if i should check all the small ones.

Also i found that the power led is connected to the inverter board.

If it is of any importance the monitor draws about 0.25 Amps with the inverter connected and about 0.11 without it.

Does anyone know if the monitor would operate without the lamps connected?
Or at least if the power led would be on??

Thanks

[selldoor]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

It is an unusual setup - it is unlikely to "work" without bulbs as it will go into protection and shut down.
With it all connected up can you anchor the black lead of your monitor to ground and with
your meter on 20vdc put the red probe on each of the 12v pins (red and yellow) on the inverter as you switch the monitor on

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

It is an unusual setup - it is unlikely to "work" without bulbs as it will go into protection and shut down.
With it all connected up can you anchor the black lead of your monitor to ground and with
your meter on 20vdc put the red probe on each of the 12v pins (red and yellow) on the inverter as you switch the monitor on

Yep, the inverter gets steady 11.6V at power on and stays there.

The On/Off white wire get 0.03V at power on. When power supply is switched of it jumps to 0.3V and goes to 0.

The only sign of life at power on is a faint blink of the backlight.

[selldoor]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

OK - Are the bulb leads soldered to the board? as against having plugs on? crazy!!
Next test is for 5 v on the other connector on the inverter board same as before as you switch on.

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Yes although the board does have plugs soldered to it! But on the other hand because it is a marine monitor they try to be as secured as possible, hence they are soldered to inverter plus hot glue on top!! (a bit of a pain to remove!).

Now the other connector. The 5V line is not used however the inverter outputs the 5V steady as soon as power is connected.

Also Pot+ and Pot have 0.25V both.

I start to think that i should make some cfl test lamps to get the lamp connection problem out of my head ... (i fixed some time ago two monitors with loose lamp cable on the lamp side.)

[selldoor]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Can you first do the same voltage test again on the LED pin.

Other queries - On the "Main?" board is the brown gunk flux or glue- can it clean off with
IPA to check its not corroding the traces. And its probably ok but in the bottom right corner of that board pic 7 there is a fuse F1 - can you test it?

Yes test cfl lamp is good - link in any budm post - I can find it if you cant.

Also can you unplug the two white plugs on the inverter and turn it over for a picture of the bottom of it.

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Can you first do the same voltage test again on the LED pin.

Other queries - On the "Main?" board is the brown gunk flux or glue- can it clean off with
IPA to check its not corroding the traces. And its probably ok but in the bottom right corner of that board pic 7 there is a fuse F1 - can you test it?

Yes test cfl lamp is good - link in any budm post - I can find it if you cant.

Also can you unplug the two white plugs on the inverter and turn it over for a picture of the bottom of it.

the voltage on the power led pins is 0.01V at all times. I have removed the brown glue under the coil and fuse is OK.

I have budm's ccfl tester link, thanks for the suggestion!

Check post #2 it is the bottom in two photos.

Thanks for the help really appreciated!

[selldoor]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Check post #2 it is the bottom in two photos.

Sorry - missed them totally - not that they help much. cant see through glue!
You are going to have to remove the glue or at least some of it.
In pic 1 the joints dont look good - but you my be able to tell better.
Next test is to work out which joints are the secondary winding posts on the
transformers- You measure both transformers ( meter on ohms 2000)
and the results have to be within 3%.
Is there a part number on the side or top of the transformers

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Transformer is CTX410805 ... I have the datasheet attached to this post.

As for the joints of the transformer it looks like soldering residue or paste.

I am trying to remove the glue to take some more measurements and i will get back to you! ....

[selldoor]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Ok I see from the pdf there are two secondary windings on each transformer ( should have been obvious but see below) one to the socket and one to the wired posts. So you need 4 to compare.

What does seem odd is that normally if there are 4 places to attach a lamp they must all have a lamp connected else the feedback picks it up as an error and switches off the
lamp circuits. I can only guess that they have disabled the no lamp detection.

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Transformers test ok in secondary. The secondaries are connected in series.

Each secondary is about 55ohms ...
Both are 110ohms ...

Now i took apart a cfl lamp but i see that there are four connections and i don't know how to proceed to connect it to the inverter. Are those two separate lamps or are they connected together??

Thanks!

[selldoor]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

See budms pic https://www.badcaps.net/forum/attach...0&d=1333950677

Each pair are twisted together and it is one lamp.

solder a wire to each pair then unsolder one ccfl and solder the now 2wires from the cfl in its place.


Whoops - see next post

[selldoor]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

STOP - may be wrong yours is a stick bulb may have 2 tubes

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

Hello,
thanks for pm ... I have not tried anything yet.

it does look like two separate bulbs but they do seem to interconnect at the end.

[budm]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

His CFL is one lamp, just twist the two wires on each end together just like what I show in my pictures.

[sententia]

Re: Nuova Marea MV-1501 (Unicont) Blink and off at power on

thanks budm!

so it doesn't matter that the board has separate connections for each wire?