How to connect Mac Mini with LG 19LS4D LCD TV?

Question

How to connect Mac Mini with LG 19LS4D LCD TV?

Hi all,
I just purchased my Mac Mini and tried connecting to my LG 19" HD TV using the supplied DVI to VGA adapter. When I first booted the machine "No signal" was displayed on my TV. I plugged in another 15" monitor and played around with resolutions and cable swapping and it works at 1024 x 768 at 60Hz (not ideal but better than nothing). Everytime I turn off the Mac Mini or it goes to sleep the resolution is reset and "No signal" appears again.

I have tried connecting via VNC to play around with the settings remotely but this has no effect on my TV monitor and is only resolved by the solution above or by leaving my Mac awake and not sleeping.

The documentation for the TV says that all the resolutions I have tried, and more are supported and Detect Displays under System Preferences shows these but defaults to a resolution that produces a "No signal" box.

Any ideas would be greatly welcomed.
Thanks in advance

Mac Mini 2GHz Intel Core 2 Duo, Mac OS X (10.5.4)

Posted on Nov 12, 2008 5:40 AM

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Answer 1

BSteely

Level 5

7,643 points

Nov 13, 2008 8:26 AM in response to jamessarjeant

Welcome to Apple Discussions, james.

I have a few questions if you don't mind. When the LG is connected to the mini and you VNC into it, under Displays preferences, how is the LG identified? Is it identified by name or generically, like perhaps "RGB Display" or something like that? If it's only identified generically, it could point to there being no Plug and Dipslay driver behind the VGA port on the LG, which could explain why the mini is struggling with it. Mac hardware, and Mac OS X in general, rely crucially on there being a P&D driver, and when it's not there, what your setup is experiencing can be the result.

Second question; again using VNC, is 1024 x 768 at 60Hz one of the options under Display preferences when the LG is connected to the mini? If it is, I would imaging that selecting it would result in a usable screen, same as when you first attach the 15" monitor and then hot swap it out for the LG. If that's not the case, then that really adds to the mystery.

Something you could try is installing SwitchRes X Control Panel on the mini and then, while it is connected to the LG, and while VNC remoted into the mini, open SwitchRes X on the mini and click on the "Export DDC" button. That will dump the LG's P&D driver data (assuming there is any) into a text file. From the text file you can see if there is a well formed driver or not. If you need help with that part, post the resulting text here for assistance.

If there is at least some semblance of a driver behind the LG's VGA port, then SwitchRes X might be able to save the situation since it can be used to build a custom (and assumed to be missing from the driver) timing that will hopefully light up the LG.

And a couple more questions; what is the native resolution of the LG TV's panel? Does the LG user guide indicate that the TV should run from a timing that is native to the panel? Also, does the TV have a DVI or HDMI port instead of VGA and have you tried that? The later might be the shortest and best path to a solution.

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Answer 2

Nov 13, 2008 8:37 AM in response to BSteely

Hi BSteely,
Thanks for the reply. To answer your questions, the LG shows on the mini as it should do i.e. there is a specific code (the LG model number) and lists the resolutions and refresh rates listed in the manual. Adobe Photoshop complains of a bad colour profile but I think that was only because when the LG is finally lit up it is as a result of me connecting the 15" monitor then hot swapping before OS X has change to realise.

When using VNC with the LG attached 1024 x 768 at 60Hz is shown but selecting that does not show the screen on the LG.

I did install SwitchResX from looking at other forums but was unable to save a usable state as the profile and resolutions were from a different monitor effectively despite my LG being connected. The P&D file that it gave back is listed in full below although I suspect this is for my 15"monitor (Excuse the length but I am unsure as to which bits are most useful).

The LG manual lists 1440 x 900 at 60Hz as the native default however the mini fails to recognise this. The easiest resolution I can get after hot swapping monitors is 1024 x 768 at 60Hz although the other day (not sure how) I did get 1280 x 1024 (at 60Hz?). The LG does not however have a DVI port. It does have HDMI so a DVI to HDMI cable could work but without buying a cable I don't know.

Here is the LG's information file:

DDC block report generated by SwitchResX version 3.8.4 for display
VGA/SVGA Display

-----------------------------------------------------
------------------- RAW DATA ------------------------
-----------------------------------------------------
0 1 2 3 4 5 6 7 8 9 A B C D E F
-----------------------------------------------------
0 | 00 FF FF FF FF FF FF 00 09 AD 38 02 BD E7 00 00
1 | 30 0B 01 01 08 1E 18 64 E8 17 26 A0 61 58 9A 2E
2 | 27 54 39 AD CE 00 01 01 01 01 01 01 01 01 01 01
3 | 01 01 01 01 01 01 C3 1E 00 20 41 00 20 30 10 60
4 | 13 00 1E 16 00 00 00 1E 64 19 00 40 41 00 26 30
5 | 18 88 36 00 1E 16 00 00 00 18 00 00 00 FD 00 3C
6 | 4B 1F 3C 08 00 0A 20 20 20 20 20 20 00 00 00 FE
7 | 00 46 58 57 4A 31 42 30 32 35 39 33 32 35 00 66

-----------------------------------------------------
< 00FFFFFF FFFFFF00 09AD3802 BDE70000 300B0101 081E1864 E81726A0 61589A2E 275439AD CE000101 01010101 01010101 01010101 0101C31E 00204100 20301060 13001E16 0000001E 64190040 41002630 18883600 1E160000 00180000 00FD003C 4B1F3C08 000A2020 20202020 000000FE 00465857 4A314230 32353933 32350066 >

-----------------------------------------------------
Valid EDID block: checksum passed

-----------------------------------------------------
------------------- MAIN EDID BLOCK -----------------
-----------------------------------------------------

EDID Version........1.1
Manufacturer........BMM
Product Code........14338 (3802) (0238)
Serial Number.......0000E7BD

Manufactured........Week 48 of year 2001
Max H Size..........30 cm
Max V Size..........24 cm
Gamma...............2.00

Display Supported Features:
---------------------------
Power Management: Active off Power Management: Suspend Power Management: Standby

Display type:
-------------
RGB color display
Display is non continuous frequency
Default color space is not sRGB standard

Input signal & sync:
--------------------
Analog input with: 0.700V / 0.300V
Composite Sync

Color info:
-----------
Red x = 0.625 Green x = 0.345 Blue x = 0.180 White x = 0.329
Red y = 0.380 Green y = 0.604 Blue y = 0.154 White y = 0.225

Established Timings:
--------------------
720 x 400 @ 70Hz
640 x 480 @ 60Hz
640 x 480 @ 72Hz
640 x 480 @ 75Hz
800 x 600 @ 60Hz
800 x 600 @ 72Hz
800 x 600 @ 75Hz
1024 x 768 @ 60Hz
1024 x 768 @ 70Hz
1024 x 768 @ 75Hz

Manufacturer Reserved Timings:
------------------------------

Standard Timing Identification:
-------------------------------

Monitor Description blocks:
---------------------------
Descriptor #0 is Timing definition:
Mode = 1024 x 768 @ 75.029Hz
Pixel Clock............. 78.75 MHz Non-Interlaced

Horizontal Vertical
Active.................. 1024 pixels 768 lines
Front Porch............. 16 pixels 1 lines
Sync Width.............. 96 pixels 3 lines
Back Porch.............. 176 pixels 28 lines
Blanking................ 288 pixels 32 lines
Total................... 1312 pixels 800 lines
Scan Rate............... 60.023 kHz 75.029 Hz

Image Size.............. 30 mm 22 mm
Border.................. 0 pixels 0 lines

Sync: Digital separate with
* Positive vertical polarity
* Positive horizontal polarity

Descriptor #1 is Timing definition:
Mode = 1024 x 768 @ 60.004Hz
Pixel Clock............. 65.00 MHz Non-Interlaced

Horizontal Vertical
Active.................. 1024 pixels 768 lines
Front Porch............. 24 pixels 3 lines
Sync Width.............. 136 pixels 6 lines
Back Porch.............. 160 pixels 29 lines
Blanking................ 320 pixels 38 lines
Total................... 1344 pixels 806 lines
Scan Rate............... 48.363 kHz 60.004 Hz

Image Size.............. 30 mm 22 mm
Border.................. 0 pixels 0 lines

Sync: Digital separate with
* Negative vertical polarity
* Negative horizontal polarity

Descriptor #2 is Monitor limits:
Horizontal frequency range.......31-60 kHz
Vertical frequency range.........60-75 Hz
Maximum bandwidth unspecified

Descriptor #3 is ASCII data:
FXWJ1B0259325

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Answer 3

BSteely

Level 5

7,643 points

Nov 14, 2008 6:05 AM in response to jamessarjeant

Yeah, that posted data would appear to be for the 15" monitor and not the LG. That's very strange the LG is properly identified within Displays preferences, that the proper timings associated with the LG likewise show up within Displays preferences, and yet when you try and capture the EDID data, it captures the data from the previously connected display. One thing you might try is a restart with the LG attached and then try and capture the EDID data (by use of the VNC remote client). That should definitely make the mini forget the 15" I would imagine. It would be good to demonstrate that the mini can successfully and properly capture the LG's display driver data using SwitchRes X's facility for this. If it can't, that would certainly point to some kind of problem with the LG and its P&D driver.

It could be that the preference file(s) for displays has corrupted. That would be something to try, namely trashing the related files so that new ones are generated. The procedure for doing that is as follows: In /Library/Preferences there should be a file labeled com.apple.windowserver.plist. Throw it in the trash or else move it to an alternate location, like a newly created folder on the desktop. Also, for however many user accounts are on the mini, there should be files in /Users/name/Library/Preferences/ByHost that are labeled com.apple.windowserver.xxxxxxx.plist where xxxxxx is a string of letters and numbers and where name is the name on the account. Move all of those files to the same temporary alternate location as well, or else throw them in the trash, then restart the mini.

When OS X restarts and finds those files missing from their expected location, it will generate fresh copies with factory default values. That should give the mini a fresh start with the LG TV and hopefully things will start working normally and as expected.

Note that throwing away the .plist files described above will also cause the loss of any custom color calibrations you may have done, or any other display specific preferences that may have been stored. Hopefully that doesn't matter to you. You can just redo them if you need them. Or if the above procedure does not accomplish anything, you can just restore the original files back to their original locations by dragging them out of the trash or the temp folder created for them and dragging them back to their original enclosing folders. You don't need to do that. You can just run with the freshly created files if you don't have anything worth saving (e.g. color calibrations) in the original ones.

If things still aren't working after trying all of the above, then the only choice that may be left is to purchase a DVI to HDMI cable and see if you get a better result from it. Either that or return the LG TV for a different one, if that is even possible at this point.

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Answer 4

Nov 14, 2008 9:58 AM in response to BSteely

Thanks for your help and patience. Attached to the bottom is is EDID info for the LG obtained using VNC etc as you suggested. I also got rid of those two files and let it create its own but still no such luck. Does this information help solve the mystery?

DDC block report generated by SwitchResX version 3.8.5 for display
19LS4D-ZB

-----------------------------------------------------
------------------- RAW DATA ------------------------
-----------------------------------------------------
0 1 2 3 4 5 6 7 8 9 A B C D E F
-----------------------------------------------------
0 | 00 FF FF FF FF FF FF 00 1E 6D 71 4B 9C 11 00 00
1 | 07 12 01 03 80 2F 1E 78 0A AE C5 A2 57 4A 9C 25
2 | 12 50 54 A5 6E 00 81 80 95 00 D1 C0 B3 01 01 01
3 | 01 01 01 01 01 01 9A 29 A0 D0 51 84 22 30 50 98
4 | 36 00 99 E6 10 00 00 1C 1A 36 80 A0 70 38 1F 40
5 | 30 20 35 00 9A E7 10 00 00 1C 00 00 00 FD 00 39
6 | 4B 1F 54 12 00 0A 20 20 20 20 20 20 00 00 00 FC
7 | 00 31 39 4C 53 34 44 2D 5A 42 0A 20 20 20 00 37

-----------------------------------------------------
< 00FFFFFF FFFFFF00 1E6D714B 9C110000 07120103 802F1E78 0AAEC5A2 574A9C25 125054A5 6E008180 9500D1C0 B3010101 01010101 01019A29 A0D05184 22305098 360099E6 1000001C 1A3680A0 70381F40 30203500 9AE71000 001C0000 00FD0039 4B1F5412 000A2020 20202020 000000FC 0031394C 5334442D 5A420A20 20200037 >

-----------------------------------------------------
Valid EDID block: checksum passed

-----------------------------------------------------
------------------- MAIN EDID BLOCK -----------------
-----------------------------------------------------

EDID Version........1.3
Manufacturer........GSM
Product Code........29003 (714B) (4B71)
Serial Number.......0000119C

Manufactured........Week 7 of year 2008
Max H Size..........47 cm
Max V Size..........30 cm
Gamma...............2.20

Display Supported Features:
---------------------------

Display type:
-------------
RGB 4:4:4 & YCrCb 4:4:4 Color Encoding Formats
Display is non continuous frequency
Default color space is not sRGB standard
Preferred timing mode includes Native Pixel Format

Input signal & sync:
--------------------
Digital Input
Color Bit Depth is undefined
Digital Interface is not defined

Color info:
-----------
Red x = 0.635 Green x = 0.292 Blue x = 0.147 White x = 0.313
Red y = 0.342 Green y = 0.611 Blue y = 0.070 White y = 0.329

Established Timings:
--------------------
720 x 400 @ 70Hz
640 x 480 @ 60Hz
640 x 480 @ 75Hz
800 x 600 @ 60Hz
800 x 600 @ 75Hz
832 x 624 @ 75Hz
1024 x 768 @ 60Hz
1024 x 768 @ 70Hz
1024 x 768 @ 75Hz

Manufacturer Reserved Timings:
------------------------------

Standard Timing Identification:
-------------------------------
#0: 1280 x 1024 @ 60Hz (8180)
#1: 1440 x 900 @ 60Hz (9500)
#2: 1920 x 1080 @ 60Hz (D1C0)
#3: 1680 x 1050 @ 61Hz (B301)

Monitor Description blocks:
---------------------------
Descriptor #0 is Timing definition:
Mode = 1440 x 900 @ 59.887Hz
Pixel Clock............. 106.50 MHz Non-Interlaced

Horizontal Vertical
Active.................. 1440 pixels 900 lines
Front Porch............. 80 pixels 3 lines
Sync Width.............. 152 pixels 6 lines
Back Porch.............. 232 pixels 25 lines
Blanking................ 464 pixels 34 lines
Total................... 1904 pixels 934 lines
Scan Rate............... 55.935 kHz 59.887 Hz

Image Size.............. 409 mm 230 mm
Border.................. 0 pixels 0 lines

Sync: Digital separate with
* Positive vertical polarity
* Negative horizontal polarity

Descriptor #1 is Timing definition:
Mode = 1920 x 1080 @ 59.934Hz
Pixel Clock............. 138.50 MHz Non-Interlaced

Horizontal Vertical
Active.................. 1920 pixels 1080 lines
Front Porch............. 48 pixels 3 lines
Sync Width.............. 32 pixels 5 lines
Back Porch.............. 80 pixels 23 lines
Blanking................ 160 pixels 31 lines
Total................... 2080 pixels 1111 lines
Scan Rate............... 66.587 kHz 59.934 Hz

Image Size.............. 410 mm 231 mm
Border.................. 0 pixels 0 lines

Sync: Digital separate with
* Positive vertical polarity
* Negative horizontal polarity

Descriptor #2 is Monitor limits:
Horizontal frequency range.......31-84 kHz
Vertical frequency range.........57-75 Hz
Maximum bandwidth unspecified

Descriptor #3 is Monitor name:
19LS4D-ZB

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Answer 5

BSteely

Level 5

7,643 points

Nov 15, 2008 8:59 PM in response to jamessarjeant

I have to say the issue your setup is experiencing is somewhat baffling. The EDID for the LG TV looks pretty good to me. The only thing that is a bit suspicious is under "Digital Input" it says "Digital interface is not defined." I'm unclear how that might affect Mac OS. Not sure.

Here's a question: If you boot with the LG and the result is no image, if you VNC into the mini and open Displays preferences on the mini, what resolution is shown as being active?

Also, have you tried starting the mini in Safe mode? I wonder if that would give a useable screen?

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Answer 6

Nov 16, 2008 3:14 AM in response to BSteely

When I hit detect displays or boot with the LG attached it comes up at 1280 x 1024 @ 60Hz. I did just notice one thing when I powered down the no signal came up (obviously as there was no computer turned on) when I booted back up the screen went blank for about 30 seconds as though it was going to receive an input but then went to no signal. Not sure if that is significant at all but seemed odd that it had to think about it first.

I will to boot into safe mode and see what happens.

Well booted into safe mode and no luck because my old monitor came up with mode not supported, my LG came up with no signal and can't VNC into the mini.

Message was edited by: jamessarjeant

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Answer 7

BSteely

Level 5

7,643 points

Nov 16, 2008 11:15 AM in response to jamessarjeant

Yeah, the more I look at this, it looks like the LG's display driver is messed up. The connection is by VGA, correct? That's an analog connection. It's properly recognized and communicated by the 15" monitor you own where you can see in the EDID display driver for that monitor the type is referenced as "Analog input with: 0.700V / 0.300V." But when making a VGA connection to the LG, the LG's driver is informing the Mac it is a "Digital input" so I'm guessing the Mac is driving the DVI port half of the DVI-I connector on the mini. That means the LG will get no signal.

I only see a few options available to you. One would be to return the TV for your money back, if that's still possible. Another would be to try a DVI to HDMI connection and see if the LG works better from that. Maybe see if the LG user guide says anything about using the HDMI input for a computer connection. A third thing would be to use a product like Gefen's DVI Detective to overcome the LG's EDID shortcomings.

http://www.gefen.com/kvm/dproduct.jsp?prod_id=4714

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Answer 8

Nov 17, 2008 1:56 AM in response to BSteely

What you said about the EDID data makes perfect sense however what does confuse me is my iBook G4 running Tiger seems to work every time with the LG using a miniDVI to VGA cable as an external monitor although it does only come up as a generic display with about 4 choices of resolution. Would that have an influence over things or not.

I shall attempt to take it back to the store. It is still under guarantee although I don't have the packaging but we shall see what they say. Would it be wise to replace like for like or move away from LG? Does anyone have any recommendations?

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Answer 9

BSteely

Level 5

7,643 points

Nov 17, 2008 7:21 AM in response to jamessarjeant

Well, the difference with the iBook could be that it has only a VGA analog output. So even if a monitor tells it to output digital, it can't. That's all I can think of.

If you can't return the TV, you could also try LG's customer support. Although trying to explain to the service person that answers the phone that there is a problem with the TV's Plug and Display driver will probably go way above their head and you might have to ask for level two or three support before you actually reach someone that knows what you are talking about. Sometimes the drivers can be field upgradeable, though in every case I have seen where that was true, it required a PC to perform the upgrade. Good luck.

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Answer 10

Nov 18, 2008 10:39 AM in response to BSteely

I have managed to track down a DVI to HDMI cable to see if that works any better if not I will have to try to return the TV and exchange it for a different model.
Many thanks for your assistance with this issue. I shall keep you updated but will mark the question as solved.

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Answer 11

Nov 20, 2008 1:23 PM in response to jamessarjeant

The DVI to HDMI cable came today and works a charm. Full range of resolutions and frequencies.
Thanks for your help.

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Answer 12

BSteely

Level 5

7,643 points

Nov 20, 2008 8:40 PM in response to jamessarjeant

Cool. Probably looks better, too.

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Answer 13

Dec 4, 2008 1:04 PM in response to jamessarjeant

i had virtually the same problem i plugged in the dvi to vga adapter which is connected to an lg screen, the apple logo came up once and then disappeared and i can't get it back up, when i boot it up it does hesitate as if something is going to happen and then nothing. do i need to get another screen as i have had the lg screen for a while? i would assume the easiest option is to get the apple screen but if there is a cheaper alternative that would be great

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Answer 14

Dec 4, 2008 3:11 PM in response to bluecombats

Hi Bluecombats,
An even cheaper option would be to try a DVI to HDMI adapter if your LG screen has HDMI input. Although if you managed to see the Apple logo it could be that one resolution and refresh rate combination could work, if you have a spare monitor that you can hook it up to, try hot swapping quickly between the two or if you have another machine on the same network try using VNC to connect and play around with settings that way.

NB: VNC may need to be set up on your main machine which could be a case of having to use another monitor to see what you are doing. On another note, when you swap monitor cables over, OS X likes to automatically update the supported resolutions so you will need to swap cables quickly.

Hope that helps but if not get back to us here.

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