Getting started with troubleshooting [Samsung 245BW]

[nerdbot]

Re: Getting started with troubleshooting [Samsung 245BW]

I don't think so. I think that unfortunately the main processor (the Genesis chip) is bad, and its excess current draw blew the diode.

Ah, ok. Let's hope so Luckily, I was able to get a (supposedly) working logic board off of ebay for $20.

[Th3_uN1Qu3]

Re: Getting started with troubleshooting [Samsung 245BW]

I dunno if this is worth 40 bucks but you might as well try if you really want to fix it. Do check all voltages on the power supply before connecting it to the new logic board, just in case something IS actually wrong with the PSU.

[nerdbot]

Re: Getting started with troubleshooting [Samsung 245BW]

I dunno if this is worth 40 bucks but you might as well try if you really want to fix it. Do check all voltages on the power supply before connecting it to the new logic board, just in case something IS actually wrong with the PSU.

Yeah, I hear you, but I figure I've already spent this much, may as well try one last time. I think the grand total I've spent so far on the 245BW, including the logic board I just ordered, is a little over $60, which is still a bit less than buying one brand new power board, and a lot less than buying a new 1920x1200 24"+ monitor. If this new logic board doesn't work, then I'll give up.

It's kind of crazy how much more expensive 1920x1200 monitors are over 1920x1080s. Must be a supply/demand thing.

[nerdbot]

Re: Getting started with troubleshooting [Samsung 245BW]

I got the replacement logic board in, wired it up, plugged it in to the current limiter, and left the inverter board unplugged. I tested a bunch of voltages to make sure things looked ok (S_B, 5.3V pins, 24V pins, voltage across the main capacitor, resistance on the various transistors with the power off, etc). Things looked ok, so I wired the rest of it up and connected the inverter board and a VGA cable.

The monitor turns on, and nothing popped, but the screen was bright white with no picture (but no longer flickering/flashing). If I moved a window onto the screen, I can see some movement (mainly very faint blue/pink streaks) that matches relatively where the window should be, but still no picture. Is this a D.O.A logic board?

One thing I did notice was that on the BL_EN pin between the logic board and power board, the voltage was reading 5.2V. The troubleshooting guide says to check that pin for "high voltage (3.3V)". Does 5.2V on that pin indicate a problem?

[Rtech]

Re: Getting started with troubleshooting [Samsung 245BW]

Check that you have plugged in the connector between logic and LCD panel correctly.A lot of members have forgot to do this,myself included, when putting the Monitor back together.

[nerdbot]

Re: Getting started with troubleshooting [Samsung 245BW]

I double-checked the signal cable from the logic board to the LCD panel, and it appears to be properly seated, yet I still have a constant white screen. Could the cable be bad? Is there any way to test it (short of buying a new one)?

[nerdbot]

Re: Getting started with troubleshooting [Samsung 245BW]

Another observation I made was that on the replacement power board I received, the smaller connector between the power board and the logic board was bent (but does not seem broken) - I attached a picture and boxed it in blue.

This connector has the BL_EN and SOS pins, and I believe a DWM or DIM pin (I can check again when I get home). If this connector is actually damaged/broken on the power board, would that explain the constant white screen on my monitor?

If so, I'll probably try removing the 5 pin transistor on this new power board and put it on my old power board.

If not, I may try to RMA this logic board instead.

[Th3_uN1Qu3]

Re: Getting started with troubleshooting [Samsung 245BW]

If those pins were broken in any way the problem would have been no backlight, not backlight and white screen. This is definitely a LCD, cable or logic board issue.

[nerdbot]

Re: Getting started with troubleshooting [Samsung 245BW]

Ok, thanks for the info. I guess I'll look into RMA'ing the logic board or getting a new LVDS cable.

[nerdbot]

Re: Getting started with troubleshooting [Samsung 245BW]

If those pins were broken in any way the problem would have been no backlight, not backlight and white screen. This is definitely a LCD, cable or logic board issue.

Well, I think it's the actual LCD panel. I got a different logic board and a new LVDS cable, as well as new cables between the logic board and power board, and I get the same behavior: solid white screen.

Out of curiosity, I connected my wife's 24" monitor (a Dell) to the current limiter, and when I turn on the monitor the light bulb flashes while the LCD is dark, then the LCD tries to turn on while the light bulb dims, and it alternates back and forth like this. I also have the same result when I connect it to my 20" monitors, so I assume this behavior is the "correct" behavior for a working monitor.

I then connected the LVDS cable on the 245BW while still using the current limiter, and this time the light bulb stays lit constantly. The LCD screen flashes momentarily then goes black, while the light bulb lights up and stays lit. Does that confirm that the LCD panel is what's drawing too much current? (As I mentioned previously, without the LVDS cable connected, the current limiter behaves "normally")

[clarioncapacitor]

Re: Getting started with troubleshooting [Samsung 245BW]

Wow you guys really cover everything on here! This thread really helped me figure out what was wrong with my monitor and hopefully when I get the parts it will be fixed!