Samsung Professional Video Monitor LH40DLPLGD/EN

[tom66]

I have seen this faulty monitor and have been offered it for a small amount. It is an LH40DLPLGD/EN. I looked it up and it seems to be a professional video monitor which costs a lot of money, but doesn't seem much different from an LCD TV, it's even got a tuner and standard video connectors, but lacks speakers. The fault is when plugged in, the green LED on the front blinks but that's it. No display. Any ideas on what might cause this? Are there common faults with these Samsung professional LCDs? I suspect it's another case of the bad Samwha capacitors that Samsung seems fond of using.

[pedro]

Re: Samsung Professional Video Monitor LH40DLPLGD/EN

The fault is when plugged in, the green LED on the front blinks but that's it. No display. Any ideas on what might cause this?

Without having any familiarity with that particular monitor, all the following is generic advice only. By far the most common cause of a blinking power LED is a SMPS attempting to start, shutting down on fault, attempting to start, etc repeatedly - especially if the blink rate is something like once a second or so. And IMOE by far the most common cause of the SMPS cycling like that is faulty caps on the rectified output, followed by a faulty rectifier, with a shorted device (e.g. 3-terminal reg on the video board) filling the minor place. Whatever the fault, it has not been isolated by killing a fuse, so you can at least perform some diagnostic work.

Open it up and eyeball the caps. If they show distress you are on the right track - if not, testing is required before they can be declared not guilty.

Measure the DC outputs at the PSU connector feeding the video board. Then disconnect the cable between the power supply and video board. If the voltages return to healthy (assuming they weren't) and/or the LED behaviour returns to steady, the fault is caused (or contributed to in a significant way) by the video board.

I realise you're not a noob, but that's my 2c worth.

[tom66]

Re: Samsung Professional Video Monitor LH40DLPLGD/EN

Well, I haven't got it yet. But I'm hoping to get it soon. Thanks for the help.

I can't find a service manual for the monitor, unfortunately.

[tom66]

Re: Samsung Professional Video Monitor LH40DLPLGD/EN

Strange. Checked back and it is working again. It seems to be on half the time and off the other half. I'm wondering if the blinking LED is a standby indication, but usually when these monitors are in standby the LED is red. I've seen them before in standby and it's red... very odd.