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

[sententia]

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

Ok.... i tried with one cfl as budm suggested ( pins connected together) ....

The cfl does blink at power on and then nothing!!

I will try the opposite lamps and maybe two afterwards....

[budm]

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

"so it doesn't matter that the board has separate connections for each wire?" Are you talking about the board in the CFL? Those two wires at each end of the CFL are for the filaments.

[sententia]

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

Ah ok!

I did try with two cfl bulbs and the same thing happens. They both flash as soon as i switch on the monitor supply.

Is it possible to operate the inverter without the logic pcb?

It does haven a on/off pin in the power connector on the inverter.

[budm]

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

Yes, there two white connectors on the inverter board, I can hardly read the labels for the pins, can you you list the labels? There should be Inverter (backlights) ON/OFF pin and Dimming control pin. The inverter board looks like it was OEM or of the shelf board. Is there any make or model numbers printed on the board some where. The inverter transformer high voltage winding resistance will need to be tested next. Please remove the board and take the pictures of the bottom side of the board, also get the P.N as printed on the inverter transformer.
Those 3 electrolytics caps on the board should also be replaced or tested.

[sententia]

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

Yes, there two white connectors on the inverter board, I can hardly read the labels for the pins, can you you list the labels? There should be Inverter (backlights) ON/OFF pin and Dimming control pin. The inverter board looks like it was OEM or of the shelf board. Is there any make or model numbers printed on the board some where. The inverter transformer high voltage winding resistance will need to be tested next. Please remove the board and take the pictures of the bottom side of the board, also get the P.N as printed on the inverter transformer.

Yes one connector is +12,+12,on/off,GND,GND and the other +5V,+POT,POT,LED,GND.

The second one outputs 5V (but not used) and the other come from brightness pot and power led.

Check https://www.badcaps.net/forum/showpo...34&postcount=5

Last photo is clearer.

It is manufactured by Unicont. Russian company with equipment for boats.

Check first posts for pics of the board.

Electrolytics were all tested ok!
P.S. It is covered with a silicone layer plus glue on many many points!

[budm]

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

OK, the ON/OFF pin control line, I expect it to be >2VDC for backlights ON, and <1VDC for backlights OFF, so check and see what it has.
So the Inverter board is made by Unicont and the model is SPB? That is what I see on the board. There must be some MOSFETs on the bottom side of the board, the inverter circuit seems to be Royer Oscillator type set up. We will need the pictures of the whole bottom side of the board, I see partial on post 2. There are 3-pin SMD devices that needs to be tested.

[selldoor]

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

Details of inverter transform posts 13 and 15
Back of board - pic post2

[sententia]

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

The whole bottom of the board in one pic.

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

The main chip on the top layer is ST. It has 339 on top line and EZNQ750 next to ST.

[budm]

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

I saw the pinout and the bottom of the board, but would like to see the whole pictures of the bottom side instead of two sections.
It looks like the 12VDC for running the inverter is generated from the step down modules, I wonder if the 12V is on steady during the lamps are turn on.

[budm]

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

The whole bottom of the board in one pic.

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

OK, that does not sound right. 0.3V is not enough to bias on Semiconductor device, minimum will be 0.6V.
There are many DC-DC inverter modules on that unit to run a bunch of board. did you check the output of those modules yet?

[sententia]

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

I saw the pinout and the bottom of the board, but would like to see the whole pictures of the bottom side instead of two sections.
It looks like the 12VDC for running the inverter is generated from the step down modules, I wonder if the 12V is on steady during the lamps are turn on.

Yes it does look steady with the multimeter and i have also tried +12V from a power supply straight to the output of the DC converters.

One 12V wire goes to logic board and from logic board there are the 2x 12V on/off and 2 GND going to inverter

[budm]

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

I am trying to trace that ON/OFF trace to see where it goes to, if you can since you have the board in front of you, may be you can see it better for me.
What we can do is to use two AA batteries to make 3VDC, put the negative on the ground, the positive will be connected to 470~1000 Ohms resistor (1/4W will be fine), then you can either remove the ON/OFF PIN from the socket or cut the wire but make it long enough that you can splice it back together. You will then connect the other end of the resistor to the ON/OFF pin on the inverter board to turn on the backlights.

[budm]

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

BTW, it is strange to see that it shows 9.36VDC as the input voltage:
https://www.badcaps.net/forum/attach...2&d=1405186673

[sententia]

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

It is designed for boats that have either 12V batteries or 24V. However DC converters work from 10V-36V and not from 9V but anyway...

Trying to find where the trace goes i realized that it has about 30K ohm resistance to the first point i can see !?

I wonder if it is broken anywhere so i am checking now...

I had to remove the small pot to be 100% sure.

[sententia]

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

I hard wired the on/off pin to the point i could see the track was going and fired up the monitor.

Backlight starts and stays on constantly!!

No other signs of life. Power button does nothing and no image on monitor.

This is confusing..... I hope i haven't damaged the logic board when changing/testing some caps ...

But may i should start checking the very small caps on the logic board??

Thanks!

[selldoor]

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

Never the less - a great step forward you know now that the bulbs work.

I was wondering if instead of soldering your jumper you touch it on - obviously it will light but then what happens if you remove it?

Is that U1 chip the ST one you gave the number for earlier?

As regards image - do you have a source connected

[sententia]

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

Ooops ... just realized inspecting the photo that i connected a different track!

I am really lucky i didn't fry anything up and find out the the inverter is working at some way!

So on/off pin goes to C28 and not C1 as i painted in previous photo!

[sententia]

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

Yes U1 is the chip i described earlier.

The only thing i found is 339 comparator which i doubt is this one ... on the other hand i am not sure....

Some other thing .. Do those zener diodes look discolored or is that normal?

[budm]

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

If we can get the P/N of U1 , then we should be able to find which pin is an ENABLE pin.
Once the backlights are on, then you should have pictures on the screen if the logic board is OK, at this point I believe you have logic board problem since the INVERTER ON/OFF pin voltage is not right, onl;y 0.3VDC when ON. I think your inverter board is OK.
Those 3 caps you replaced are for the buck regulator that step down the 12VDC down to either 5V or 3.3V to run the logic board, you should check the DC voltage right at the two legs of those caps to see what you have.

[selldoor]

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

Struggling with the datsheet any chance of cleaning up the top of U1 and getting a close up picture to show the part number. I have spent many hours looking for parts using wrong numbers B-3-8 D-O 0 2-S-5 and so on.