No backlight on lcd display - Alpine TDA-7547

The problem is probably the backlight of the LCD display or the LCD display. It's hard to determine which but either repair requires opening the case of the sewing machine to access the LCD. This site, https://janomememorycraft.com/products/baby-lock-esante-esi-2-lcd-backlight-replacement-kit , has a replacement backlight and a manual that walks you through the steps. This site, http://bargainbox.com.au/babylock-esante-esi2-replacement-lcd-backlight/ , has the LCD screen.

I hope this helps.

Cindy Wells

The LCD display contains both the display and backlight. They are integrated as one piece. Therefore the entire display needs to be replaced. The backlight connections are soldered to the LCD connections. Replace the entire display.

First, make sure that your brightness is turned up. You can access this from the menu by selecting "Display" then adjusting the display between 50% & 100%.

If the brightness is at 100% and the display is still dim, this is an indication that there is a problem with the backlight that lights up the LCD display from behind.

The backlight is integrated into the LCD display, so the entire display needs to be replaced. Was the unit dropped? If so, perhaps the LCD flex cable pulled out of the connector, slightly from one side, disconnecting the backlight. We strongly suggest that you don't try to repair the unit yourself. Additional damage can occur.

More information on LCD repair can be found here:


SHARCNET USA Out of Warranty GPS Digital Camera Repair

An LED TV is still an LCD TV, just with LED backlighting. That model is an LCD TV. The difference is in the backlight. Both LED and LCD TVs use an LCD screen. LED TVs have LED backlighting of the LCD screen, which saves energy.

Backlights are part of the LCD display and consist of LED's. You may have to replace the entire LCD display or find another display that is cracked but has a working backlight. In most cases, you can swap backlights. There may be some soldering involved.

A) Replacement LCD screen backlight could be bad.
Happens. Sometimes you get a bad part. (Bad LCD screen assembly, in this case)

LCD screen may not be the correct one.

http://support.gateway.com/s/Mobile/2008/GodzillaFX/2528410R/2528410Rsp2.shtml

http://support.gateway.com/s/Mobile/2008/Godzilla/2528407R/2528407Rmv.shtml

A screen Inverter, and an LCD screen; are a MATCHED unit.

B) Screen Inverter:
May be bad, or the Wrong one

C) You may not have the screen Inverter, connected correctly to the Backlight.
Connections aren't tight.

D) The Display Cable TO LCD screen connection may not be tight, or correctly connected.

I know the display shows graphics, but a poor connection of Display Cable to LCD screen, can make the Backlight dim out.

I'm betting it is a poor connection, or the wrong screen Inverter, or wrong LCD screen.

Regards,
joecoolvette

(Be shame to kick that laptop to the curb. Nice laptop)

1) Toshiba Satellite P300-13j LCD screen example,

http://www.screentekinc.com/Toshiba_Satellite_P300D-13J--17-inch--1440x900-wxgaplus-laptop-lcd-screen.shtml

Thin Film Transistor (TFT) Active Matrix LCD screen, that is WXGA, and uses one CCFL for a Backlight.

2) http://www.lcds4less.com/ToshibaLaptop__Toshiba_Satellite_P300D-12L__laptop-screens.html

Thin Film Transistor (TFT) Active Matrix LCD screen, that is WXGA, and has 1 CCFL for a Backlight.

There is a pretty good chance. The screen Inverter and LCD screen are a matched unit. I would remove the screen Inverter from the P300-12L, and use it also.

Looks like this,

http://www.lcd-inverter-shop.com/Toshiba/Toshiba-Satellite-P300D.html

If I may ask;
1) Is there obvious damage to the LCD screen?

2) If there is not obvious damage to the LCD screen, have you used an external VGA monitor with the laptop?

To see if the problem is the graphics chipset, or the video cable, or inside the Display Assembly.

A) http://www.irisvista.com/tech/laptops/Toshiba-Satellite-P305/take-apart-notebook-1.htm

B) http://www.irisvista.com/tech/laptops/Toshiba-Satellite-P105-P100/remove-lcd-screen-inverter-1.htm


Post back in a Comment.
Regards,
joecoolvette

[Primer:
An LCD screen cannot produce light by itself,
(Click on the monitor icon,

http://solutions.3m.com/wps/portal/3M/en_US/NA_Optical/Systems/BehindTheScenes/Optics101/ )

It needs an additional light source. A Backlight is the additional light source.
A Backlight can be a CCFL, (Or two of them), or a series of LED's.

LED stands for Light Emitting Diode

CCFL stands for Cold Cathode Fluorescent Lamp.
Similar to Fluorescent lighting used in homes, and businesses, but on a MUCH smaller scale.

Average thickness is 2mm. That is a little larger than 1/16th of an Inch.
Average length is almost as long, as the LCD screen is in height.

http://www.laptoprepair101.com/laptop/2007/12/09/replace-laptop-backlight-ccfl-lamp/

Observe the last 8 photos especially. This article shows you that the LCD screen is an assembly. It is composed of layers. Just like the 3M company's tutorial. Also shows general instructions for replacing a Backlight.

A screen Inverter is used to convert the power from the laptop, for the LCD screen, and Backlight.
It is a small circuit board, and is usually mounted towards the bottom of the LCD screen, and behind the Display Bezel.

A CCFL, (Or two of them), uses a screen Inverter.
LED backlighting however, may or may not use a screen Inverter.

Using LED's for backlighting is relatively new, when discussing backlighting technology.
Some of the first designs of LED backlighting does use a screen Inverter.
Newer designs do not seem to.

90 PERCENT OF THE TIME the problem can be attributed to a bad screen Inverter.

It is possible that the backlight has quit working. Use a flashlight, held at an angle to the display, to see if there is a faint image visible. If so, then have backlight repaired. Otherwise, try a different input / cable.

IS GREEN LIGHT IS ON BEHIND LCD ? ANY LCD NEEDS BACKLIGHT TO DISPLAY. JUST LOOK OUT FOR FUSED BACKLIGHT. LET THE DOOR OPEN OR CLOSE THE DISPLAY SHOULD BE ON.