Pelco 42 inch Monitor Shuts off .5 secs

[budm]

Re: Pelco 42 inch Monitor Shuts off .5 secs

What I am saying is that the problem you have is that the backlights problem flash on and then go off but the monitor is still in power up mode, so the failure is in the either the inverter board or worn out lamp which will cause the backlight circuit to shutdown.
In your thread description: 'Pelco 42 inch Monitor Shuts off .5 secs'
It should be: The monitor stays on (Power LED stays Green) but the backlights shutoff after 0.5 second.

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Wait so after powering it on again and testing after the green light was on and it was I presume powered on the voltages show 1.06v for the inverted board. So 28v in standby and 1v powered on. So does this indicate a bad psu?

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Yes but I thought if that was the case I would be able to still see an image with a flashlight if ti was a backlight.

[budm]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Wait so after powering it on again and testing after the green light was on and it was I presume powered on the voltages show 1.06v for the inverted board. So 28v in standby and 1v powered on. So does this indicate a bad psu?

OK, I am a little confused, the 24V pin on the power supply connector is showing 28VDC when the monitor is in STANBY (POWER LED is not Green), and then goes to 1.06V when power switch is activated (Power LED is Green)?
The 24V power supply should not be putting out 24V when in standby (no ON command from the main board to turn on the 24V power supply section).

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Pics of inverted board http://imgur.com/a/LyFJ6

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

OK, I am a little confused, the 24V pin on the power supply connector is showing 28VDC when the monitor is in STANBY (POWER LED is not Green), and then goes to 1.06V when power switch is activated (Power LED is Green)?

Yes exactly.

[budm]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Yes exactly.

Well, that makes no sense to me if the power LED is RED and you are getting 24V (28V).

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

I'll recheck but that seems to be the case idk what to say. On the mainboard DC connector I get 12v and 5v and 28v in standby. Ok on this time testing once powered on I'm getting 1.0v on 5v stanby and on the 28v inverter pins I'm reading 0.68v.

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Also not sure if this has to d with anything but this is designed as Security camera monitor not a TV. Doesn't Seem to me that would make any difference but just putting it out there. I will take pics of the pins right now.

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

I'll go thru and mark each pin right now the exact voltages in standy and powered on.

With a clear pinout and picutres of the pins. Give me 20 min.

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

well i shorted 12 to gnd while testing pins so I guess I'll have to find the fuse I blew now.

I wont be back in my shop for couple days so i guess ill put this off to the side until then.

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Well now I'm back at it again. The board is no longer supplying power to the mainboard as I am unable to turn it on. I am looking for I may have blown when I shorted 12v- to ground. I did not have anything connected to the PSU when I did that so it must be on that board. If you or anyone else can help point me where to look I'd appreciate it. At this point its a learning experience for me more then a repair.

Or if you think its a lost cause I found an inverter board and power supply board for pretty cheap but I'd rather learn on this one before I call it a day and just swap out parts.



I uploaded some more pics of the main board along with where I shorted 12v to gnd.

I also took a pic of a large diode which seems to be open??

http://imgur.com/a/pgfRI

there are two of those on the board and both test open. So could this be the issue?

Thanks

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Model number is PMCL542F by the way for anyone searching. I tried to edit the title but it seems its not allowed.

[budm]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Can you please do the straight shots of the board both top and bottom side?

[budm]

Re: Pelco 42 inch Monitor Shuts off .5 secs

BTW, the main AC fuse (white fuse) by the AC inlet connector with Black and White wires is OK?

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

yes ac side is fine and still makes the rattle when I plug it in except for its about have the length of time that it was before I shorted it.

[budm]

Re: Pelco 42 inch Monitor Shuts off .5 secs

So at this point are there any DCV on any of the power supply pins that goes to the main board? You should at least have the Standby Voltage for the main board, the Switched 12V/24V will not be present on the power supply board until the main board sends the PS-ON to run on the 12V/24V circuits.

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

http://imgur.com/a/Ycdxh

here are pics as good as I could get them. When I last checked there was no standby at all and when I checked the red power light is not on.

But I will hook up the boards again and try it out.

[budm]

Re: Pelco 42 inch Monitor Shuts off .5 secs

You can test the power supply board by itself since the standby power supply is an always on power supply which the Voltage should be present the minute you apply the MAIN AC to the power supply board.

[neverexisted]

Re: Pelco 42 inch Monitor Shuts off .5 secs

Ok it does indeed have 5v standby