Need expert advice on LCD panel compatibility

I'm needing some expert advice by someone who knows about LCD panels.

I have a couple Dell Studio 1458's that came with 1366x768 LG Panels (LED Backlit P/N LP140WH1). This model Studio 1458 also is available (but rare) with a 1600x900 option, also an LG panel (LP140WD1). So I bought a couple of the HD+ 900p panels to retrofit the two 1458's.

The existing panels and the new panels look identical. Connector and everything. I replaced one of the panels with the WD+ panel and turned on the 1458. I got a display, but blacks were purple. Not good.

I, of course, triple-checked the connection (a single cable on this panel), and it was connected properly and secured by sticky tape. It looked fine. So, I tried the 2nd panel I bought, thinking the first was possibly bad. After connecting the 2nd HD+ panel, and turning on, I got nothing. As a matter of fact, it appears the 1458 was not initializing correctly as the fans were running full speed and hot air was coming out.

At this point, I turned off the 1458, and put the original panel in, and still nothing.

So, BIG QUESTION...given these two LG panels that are identical in all respects but resolution, should they be compatible to the point of being able to exchange one for the other, or was there something else I needed to change (like the data cable from the system board to the LCD?).

Given the results here, I probably already know the answer, but if someone knows FOR SURE about these panels, and can give some advice, I'd appreciate it.

Right now, I have a dead 1458, and not sure of the status of the two new panels...are they damaged now or are they probably still good?

Thanks.

 

Likely an issue of single LVDS vs dual, but this is dell they like to do things differently.

 

LVDS? Is that something that is on the panel or the system board?

Since these Studio 1458's come both ways, I would think that the system board or graphics chips is the same, just the panel is different.

Do I need a different cable?

 

Look at the LCD cable: for high resolutions you want all connectors to exist. Basic cables have only half of them, rest missing. If that's the case, you might want to try another cable.

 

I'll check that.

Also, an update...I thought the Studio 1458 was dead, but in fact, it is working, it's just that the LCD panel backlighting is dead. If I shine a light at the panel, I can see the image. Both the original panel that came with the 1458 and one (or both) of the new 900p panels have no backlighting, so would that be the system board is bad???

Why does this have to be so complicated!!!!

 

Higher res CCFL (old style) panels draw a LOT more power.

My guess is you killed the inverter board, higher res ones will need a more robust inverter. (unless its an LED backlit panel).

Check the image more carefully, is it every other line showing on the 900p panels? If so you need a new cable too.

 

Sorry, but both the original panels (768p) and new panels (900p) are LED backlit. NO CCFL types. No inverter boards. The panels are identical, almost down to the part numbers (see the first post).

All there is is just the 40 pin connector going to the panel. I assume the LED backlight power source comes through that cable since it's the only cable!

The first time I plugged in the 900p panel today, like I mentioned in the first post, the screen was OK, except blacks were purple. I do not recall anything like every other line missing. I'll try to look again but it's very hard to see anything with the backlighting dead. A flashlight kinda works, but it's still very hard...

 

Hmz, odd. They do still draw a bit more power than the smaller types. Maybe dell REALLY skimped on the power circuitry for the monitor on the low res versions.

Worth trying with a different cable if you can.

 

Maybe a stupid question but did you also try the keyboard shortcuts to turn the screen on and off along with adjust brightness? Maybe the screens just never initialized properly, I know this is an extremely slim chance but it is free to try.................

 

That's exactly true. No separate inverter like CCFL would have. That's why you should replace the cable first if backlight is out, it could just be a faulty cable (and a good reason to get one with all pins connected too).