My lifebook 4215 doesnot display on its screen but can display to an external monitor because the output section of the mb has no small ic like components and a cable jack can I please have a proper schematic/circuit diagram of the mb

Have you consulted any troubleshooting sections in the documentation for your notebook ? Do so.
Next you could try connecting an external monitor to your computer, using the port on the side of your computer Its a VGA port I believe so you will need a VGA monitor and suitable cable or another type of VDU and cable/adapter. There should be a button on your keyboard to switch displays (built in screen/eternal monitor/both cycling between the combinations on my HP it's the f4 button). If you cannot get this to work it is a problem either with your m/b or less likely software. If your external monitor works then maybe the small cable connecting your computer to its display has become unplugged, or else the screen has failed, most likely the inverter, which can be relatively easily be replaced. If the service manual does not describe these procedures search the internet, most likely there is a video on how to carry out this procedure on youtube.
You might need to carry out a lot of research and reading to diagnose and solve a problem.

24.May.2015

Check external monitor settings on Fijitsu.

I suspect it may be a problem with the video cable coming from the convertible tablet, up through the hinged support for the LCD screen, AND/OR the screen Inverter.

I would like you to connect a VGA monitor, to the VGA port on the back of the convertible tablet. The VGA monitor will now be an External Monitor.

[ Looking at the rear of the convertible tablet, start at the Left side.
Vent, USB port, Monitor port. The Monitor port is the VGA port ]

The VGA monitor can be a CRT type, (Looks like a small TV), or a flat LCD screen monitor with a VGA cable.

Notebook OFF, monitor OFF, connect the VGA monitor to the M275's VGA connector. (Port)
Turn the monitor on. If a CRT type, allow it to warm up.

Turn the notebook on.
By the factory default settings, whatever is shown on the convertible tablet's internal monitor, should now be shown on the external monitor.
(VGA monitor)

If not, press, and hold down on the Fn key (On the bottom row of the Keyboard, all the way to the Left), and tap once on the F3 key.
(Top row of Function keys. The F3 key is the Display Toggle-Over Key )

No graphics shown on the external monitor? Hold down on the Fn key again, and tap the F3 key again.
There are at least three options available;

1) Convertible tablet's internal monitor - ONLY
2) Convertible tablet, AND external monitor
3) External monitor - ONLY

If graphics are fine on the external monitor, you have a problem with the video cable, and/or the screen Inverter. At this time we will bypass the LCD screen, and come back to it.

At the bottom/middle of the tablet's LCD screen, is the Hinge. The Hinge Cover is 'T shaped', and has one single Philips screw holding it on.
If you remove the screw, and the Hinge Cover, you will see two wire harnesses.
One Black, the other White.

See that these two cables are plugged in tightly to the connector.

After checking this step come back in a Comment, and state your findings.

Regards,
joecoolvette

[ Additionally;
Here is the Service Manual (Free) for the Gateway M275 Convertible Tablet,

http://www.tim.id.au/blog/tims-laptop-service-manuals/#toc-gateway

Where it states - Gateway 400, go down to the second line, and across to M275. Left-click on M275.
This is a PDF file. It may take up to 30 seconds before the first page comes up.

Getting bigger, staying small - the LIFEBOOK P1610 is more than only a notebook.

Rotate the brilliant 8.9 inch (1280 x 768 dots) display 180 to share your ideas or flip it over to convert your notebook into a slate Tablet PC.

Hi, it is possible that the Ram may be faulty,or the Screen so to confirm,connect external monitor to the VGA port(Blue in color) and also check each RAM chip one after the other to bring out the the faulty one.

Do you have Windows 10? As there may be an issue with screen rotation.

However to check your settings:

1. Place the tablet into Pad/Tablet mode.
2. Click the Start menu and select Settings.
3. Click System.
4. Click Display.
5. Scroll down and check the status of Lock rotation of this display .

When you connect a data projector or external monitor to the external video port on the laptop, power up the data projector or external monitor first then the laptop. The video info will automatically divert to the data projector/external monitor automatically.
If you have already had powered up the laptop first, most laptops will allow you to toggle between the LCD screen and the external video port by pressing the Fn key plus one of the Function keys, this key will have a screen/laptop symbol.

CONNECTING VIA VGA CABLE,RIGHT CLICK ON THE DESKTOP SELECT DISPLAY,
CONNECTING EXTERNAL DISPLAY,
MIRROR ON ALL DISPLAYS
WALLA AND BOB'S YOUR UNCLE

HOPE THAT SOLVES THE PROBLEM.

You can update graphics driver, if that does not fix the issue check the display on external monitor. If the external monitor works fine you can isolate checking the display in BIOS Setup scree (Restart your computer and keep tapping F10 to getinto BIOS). If the same issue in BIOS, you may have to change display of the unit.

Use your Q menu to select the "Internal and External" display. If this choice is not enabled on your Q menu, go to tablet settings and enable it there.