When i connect my laptop Hp Pavilion dv4 to a sony lcd projector, it shows that the frequency is out of range. how to i adjust the frequency to be in the range so that my desktop will show up on the external lcd projector?

this is easy, that OUT OF range means
the PC sending video is sending and illegall higher resolution
than the projector supports (or even less, on this old junk)
the manual on that old projector is clear on that. max.
SONY VPL-EX4 2007, 13 years old now.
and back then projectors STINK !
your manual shows this, and stinks.
what stinks worse is no matrix of legal H./V resolutions shown in the manual. (shows only 1)
so set the PC to 1400 x 1050 and do not use others . ok.
and 60Hz, are you in USA? not stated country.

Sony VPL DX 100 is a native XGA projector [1024x768]
so if u connect to a PC that has higher resolution than XGA , it will not be able to project and will show u out of range .
you will need to reduce the screen resolution in your resolution settings to XGA and the problem will be solved.
On a Laptop however, the graphics card should automatically identify the native resolution of the projector and adjust the screen resolution that is being sent from the graphics adapter.
you can also repalce the VGA cable and check if the problem gets solved as a broken pin or cable internally can also result in a similar problem!

Since you have graphics on an external monitor, the problem is the Video Cable, or inside the Display Assembly.

http://h10025.www1.hp.com/ewfrf/wc/product?product=3860431&lc=en&cc=us&dlc=en&lang=en&cc=us

This is a general example of a Video Cable, (Display Cable - HP), for an HP Pavilion DV4 series of Notebook PC,

http://www.ebay.com/itm/NEW-ORIGINAL-HP-PAVILION-DV4-LAPTOP-LCD-VIDEO-CABLE-DC02000IO00-486878-001-14-1-/281038275215?pt=US_Laptop_Screens_LCD_Panels&hash=item416f2fc28f

Mouse over to enlarge

The Video Cable connects to the motherboard in an area under the Keyboard, (About where the Fn key is), routes up along the motherboard, then routes up through the left Hinge, and into the Display Assembly.

From there it connects to the screen Inverter (Display Inverter -HP), and back of LCD screen.
It also connects to the LED backlight.

Either connections are loose, or the Video Cable (Display Cable) is damaged.
If the sheath of the cable shows apparent visual damage, so may be the tiny wires inside. (Stretched/Broken)

Connections CANNOT just be visually determined if they are loose.
You MUST physically check EACH connection.

Tightening connections does no good?
Perform a continuity test with a multimeter set to OHM's, on every wire in that Video Cable.

Have an assistant gently wiggle the cable in the middle, and check for an intermittent reading on the multimeter. Indicates broken wire if intermittent reading shows.

OR,

Take Video Cable to the nearest small computer store, and have the resident tech check it for continuity. Should just be a couple of bucks.

Use an ESD wrist strap, and connect it's alligator clip to a good ground source. (Electro Static Discharge)
Average cost is around $3 to $6.

Here is the download page for the free Service Manual, from HP Support,

http://h10025.www1.hp.com/ewfrf/wc/manualCategory?cc=us&dlc=en&lang=en&lc=en&product=3860431&

Scroll down, click on -
HP Pavilion dv4 Entertainment PC - Maintenance and Service Guide

Page 92 (PDF page at Top) for motherboard side of Video Cable (Display Cable - HP)

Page 80 for LCD screen, and Screen Inverter (Display Inverter - HP), and LED backlight.

Page 82 has false statements.

Remove the display assembly:

1. Locate the wireless antenna cable (1), and remove from path (2)

Should be;
Locate the DISPLAY CABLE (1), and remove from path (2)

2. Disconnect the wireless antenna cable from the system board (3)

Should be;
2. Disconnect the DISPLAY CABLE from the system board (3)

Somebody was on crack that day.

The wireless antenna cable information that follows, is correct.

Video Cable (Display Cable) is on the Left side.
Wireless Antenna wires are on the Right side.

For additional questions please post in a Comment.
Regards,
joecoolvette

If you are lucky, this may be down to a loose vga cable connection on the back of the screen, or at the motherboard.

First eliminate the possibility that t may be graphics chip related by seeing if the laptop will work on an external monitor without the banding you describe. If it will, you will need to remove the laptop screen and see if the connection there is tight. Check also at the motherboard end (remove keyboard and switch panel)

If it is tight, then suspect that the screen is beginning to fail, look for a replacement.

If the monitor shows a similar pattern, the issue is with the graphics chip ( common problem with HP laptops)

If you have to ask "how", I strongly recommend that you STOP, and instead take the HP to an authorized HP Repair Depot, and get the repair done correctly, quickly, safely, and efficiently, at no "risk" (one mistake, and you turn your laptop into a $500 "paper-weight" or "door-stop").

Few trouble shoot solution when it comes to these HP Laptop from 08-09.

1). Remove battery and ram. Plug in AC Adapter and insert only ONE RAM into a slot. Boot up and see if this will turn on display (it work on a HP Dv4-1225dx) IF it works then shut down and re insert the two ram and should be good to go :)

2). If your tech savvy remove keyboard and gain access to LCD flex ribbon cable to check if cable is loose (or go on a limb and replace the lcd flex cable ). I would detach it and re attach the ribbon back to motherboard. ( This happen sometimes by chance)

3). Your LCD is shot dead so it will need to be replaced. Current used LCD can range from $40-$50 and new ones with warranty $60-$100. HP is set up for easy LCD removal so shouldn't take more then 30mins to replace, just be careful when handling the ribbon and inverter cables.

GOOD LUCK
(Fix many HP Laptop for friends and family)

install driver mother board CD

Below is the link to your service manual, the LCD removal procedure starts on page 81.....

http://h10032.www1.hp.com/ctg/Manual/c01597750.pdf

If you are attempting to connect an LCD projector to a laptop,you connect a monitor cable to your video card and the other end to the monitor input connector. You may have to use an adapter, I know on my LCD projector I had to use a DVI to VGA connector.
Can't say much more not knowing if you are having a problem with a particular brand of projector

Pl. send me solution. I am stuck with problem

vpl-es4 sony projector-frequency out of range.