PANEL FAILURE OF SAMSUNG LE26R32 LE26R81 LCD-TV - REPAIR GUIDE FOR V260B1-L04 ( P/N : BN07-00364A SAMSUNG )

 

Panel failure of LCD-TV LE26R32 LE26R81  LCD-TV

 

 REPAIR GUIDE FOR V260B1-L04 ( P/N : BN07-00364A )  Samsung


In case of panel failure of LCD-TV using BN07-00364A ( V260B1-L04 ) -  Samsung LE26R32 , Samsung LE26R81 , we
usually met below symptoms :
- blanc image (white) at startup , correct image appearing after 5-20 min - sometimes over blanc image appear some H-lines , the number of lines and position on display is different at consecutive startups .

- during operation , the image becomes “still” and after turning to white , disappearing . In both above cases the display is sensitive when torsion it , close to moment the image appear ( first case ) or “still” ( second case ) . The cause of above symptoms is the failure of one of contacts between the first IC-FPCB in the upper-left corner of display and upper long and narrow PCB of display . Unlike the rest of FPCBs with drivers for vertical lines , this one have some circuits that just passing through it , to some circuits over panel glass , and through these , to the first of three drivers for H-lines on left side of panel glass .

The access to “long-and-narrow” PCB in the upper part of display , and to FPCBs is only possible after removing of front metal frame of LCD display ( fixed in 10 screws ) . 

The T-Con board must also be removed . The repair solution described below requires good skills , so please don’t do it if you haven’t done operations of similar complexity .

In pictures P01, P04, P05,P06 is described the correspondence between pads on first upper H-driver ( please note that pads are accessible below H-driver FPCB when LCD display is on the table ) . Attention ! all of these pads ( numbered in P01 from 1 to 15 ) are covered with a green flexible paint . To detect the interrupted circuit , please scratch gently the paint on the center of each pad ( P03.jpg ) to can contact them with the tester of multi-meter .

I recommend to use for scratch a new surgical scalpel ( curved , not straight ) . It is very important that the scalpel to be a new one , not a blunt one . Attention !!! Be careful when scratch center of pads , don’t touch with scalpel the thin circuits near the pads . For easily access to pads and to avoid the dust and foreign materials to enter between backlight and LCD- panel , carefully and gently lift up the driver FPCB and fix it with adhesive tape in vertical position to don’t excessive stress the FPCB , but enough to can access the pads with scalpel , tester and soldering iron .

If you consider unsafe lifting of driver FPCB , is better to lift the whole LCD-panel ( glass ) and put it “up side down “ , but take care of any dust and foreign object to avoid dirty the display . Take care also of driver FPCBs between the long upper PCB and display , don’t excessive stress them . The most frequent circuit found interrupted is that one corresponding to pad numbered 10 ( P01.jpg ) and indicated in P03D.jpg .

For easily measurement , please measure the continuity of this circuit to the pad numbered 10 in P06.jpg ,
near the connector to T-Con board .

You can read below the normal resistance values for all circuits ( all are so big values because of thin circuits on the glass ) . There are also the normal voltage value that can be measured during function and the voltage drop on each circuit ( where is not specified , is below 0.1mV )

Please note that pads numbered with 11, 12 , 14 are not connected , so don’t measure them .

• 1 -> 1st line (-5.5V)
• 2 -> 13Ω ( -5.51V , 7mV )
• 3 -> 17Ω ( +21V , 12mV )
• 4 -> 13Ω ( -5.51V , 8mV )
• 5 -> 50Ω ( 3.29V , 4.1mV )
• 6 -> 61Ω ( GND , 3.5mV )
• 7 -> 91Ω ( 3.3V )
• 8 -> 84Ω ( 917mV )
• 9 -> 84Ω ( 1.73V )
• 10 -> 84Ω
• 13 -> 20Ω ( +5.37V )
• 15 -> 84Ω ( 3.3V )

In case you find interrupted circuit corresponding to pad 10 ( or resistance >> 84 Ω ) , this must be bypassed with a thin wire CuEm φ 0.15 mm ( thermoplastic insulation preferably ) . Please cut first the wire at 120mm length and tin it with soldering iron ( max 1mm ) . Also , tin with soldering iron ( adjusted at 270°C )the pad numbered 10 on FPCB , only where paint is scratched ( P07.jpg ) . Please use normal soldering alloy ( 40/60 ) not Lead-free . All these operations must be done with the display disconnected ( and completely isolated from any metal part of table ) , using the antistatic bracelet connected to soldering iron ground contact . Please solder an end of prepared thin wire to pad 10 ( P08.jpg , P09.jpg ) . Release the driver FPCB by carefully and gently unstuck of adhesive tape . Don’t excessive stress the FPCB . Prepare a 5mm strip of adhesive tape and stick the FPCB ( P10.jpg ) . Position carefully the wire ( P11.jpg ) , fixing it from place to place with thin ( 3mm) strips of adhesive tape .

Find the crossing hole numbered 10 in P04.jpg , P05.jpg and tin it with soldering iron . If you consider difficult to use this point to solder the wire , you can use the pad near the T-Con connector ( P06.jpg) – but you must use a longer wire . You also must take care to isolate it along its route . Solder the end of wire on prepared cross hole ( P13.jpg , P14.jpg , P15.jpg ) - or to above specified point , and after , fix the rest of wire (P13.jpg ) .

In case you don’t find at first measurement an evident interruption of circuit corresponding to pad 10 , before solder the wire to cross hole connect again the ohmmeter between end of wire and pad 10 near connector , and gently touch the side of upper driver FPCB ( the side near the display side ) and look for a resistance variation . If you don’t observe any variation , you must search another interrupted circuit , and bypass it too .
( 10 must be bypassed anyway ) .