Panasonic KX-UT248RU / KX-UT248RU-B (serv.man3) Service Manual ▷ View online
53
KX-UT248RU/KX-UT248RU-B
11 Maintenance
11.1. Terminal Guide of the ICs Transistors and Diodes
11.1.1. Main Board
54
KX-UT248RU/KX-UT248RU-B
11.1.2. Ope Board
11.1.3. Backlight Board
B3AFB0000370
Cathode
Anode
55
KX-UT248RU/KX-UT248RU-B
11.2. How To Replace a Flat Package IC
Even if you do not have the special tools (for example, a spot heater) to remove the Flat IC, with some solder (large amount), a sol-
dering iron and a cutter knife, you can easily remove the ICs that have more than 100 pins.
dering iron and a cutter knife, you can easily remove the ICs that have more than 100 pins.
11.2.1. Preparation
• PbF (: Pb free) Solder
• Soldering Iron
• Soldering Iron
Tip Temperature of 700
°F ± 20°F (370°C ± 10°C)
Note: We recommend a 30 to 40 Watt soldering iron. An
expert may be able to use a 60 to 80 Watt iron where some-
one with less experience could overheat and damage the
PCB foil.
expert may be able to use a 60 to 80 Watt iron where some-
one with less experience could overheat and damage the
PCB foil.
• Flux
Recommended Flux: Specific Gravity
→ 0.82.
Type
→ RMA (lower residue, non-cleaning type)
Note: See About Lead Free Solder (PbF: Pb free) (P.3).
11.2.2. Removal Procedure
1. Put plenty of solder on the IC pins so that the pins can be
completely covered.
Note:
Note:
If the IC pins are not soldered enough, you may give
pressure to the P.C. board when cutting the pins with
a cutter.
pressure to the P.C. board when cutting the pins with
a cutter.
2. Make a few cuts into the joint (between the IC and its
pins) first and then cut off the pins thoroughly.
3. While the solder melts, remove it together with the IC
pins.
When you attach a new IC to the board, remove all solder
left on the land with some tools like a soldering wire. If some
solder is left at the joint on the board, the new IC will not be
attached properly.
left on the land with some tools like a soldering wire. If some
solder is left at the joint on the board, the new IC will not be
attached properly.
11.2.3. Procedure
1. Tack the flat pack IC to the PCB by temporarily soldering
two diagonally opposite pins in the correct positions on
the PCB.
the PCB.
Be certain each pin is located over the correct pad on the PCB.
2. Apply flux to all of the pins on the IC.
3. Being careful to not unsolder the tack points, slide the sol-
dering iron along the tips of the pins while feeding enough
solder to the tip so that it flows under the pins as they are
heated.
solder to the tip so that it flows under the pins as they are
heated.
11.2.4. Removing Solder From Between
Pins
1. Add a small amount of solder to the bridged pins.
2. With a hot iron, use a sweeping motion along the flat part
2. With a hot iron, use a sweeping motion along the flat part
of the pin to draw the solder from between the adjacent
pads.
pads.
56
KX-UT248RU/KX-UT248RU-B
12 Schematic Diagram
12.1. Main Board No.1
(2)
(1)
(a)
KX-UT248
RU
MAIN BOARD No.1 1/4
1/4
B
A
C
E
D
34
2
1
6
5
cpu_xa9
cpu_xa11
ASICRST
I2C_SCL
ASICCLK
I2C_SDA
XA0
F_CE
*OE
XD0
XD8
XD1
XD9
XD2
XD10
XD3
XD11
XD4
XD12
XD5
XD13
XD6
XD14
XD7
XD15
XA16
XA24
XA1
XA2
XA3
XA4
XA5
XA6
XA7
XA17
XA18
XA21
*WE
XA20
XA19
XA8
XA9
XA10
XA11
XA12
XA13
XA14
XA15
XA22
XA23
XA13
XA8
XA14
XA9
XA11
XA4
XA10
FLASH_nRST
LCD_D0
LCD_D1
LCD_D2
LCD_D3
LCD_D4
LCD_D5
LCD_D6
LCD_D7
LCD_CS
LCD_WR
LCD_RS
LCD_RD
BKLTPWM
cpu_xa4
cpu_xa20
XA20
XA5
cpu_xa13
cpu_xa8
cpu_xa14
XA2
XA6
XA1
cpu_xa2
cpu_xa10
LCD_RST
E_MDCLK
002:A3
E_TXEN
002:A2
PHY_nRST
002:A3
E_RXD3
002:B1
E_TXER
002:C1
E_COL
002:B1
E_RXD1
002:B1
E_CRS
002:B1
E_MDIO
002:A3
E_TXD0
002:A2
C531
NC
C532
NC
DG
USBM
001:10C
USBP
001:10C
SPP
004:3C
SPN
004:3C
MIP
004:3D
R511 4.7k
1
2
3
4
2
3
4
5
6
7
8
DE_READY
001:9F
DE_PDN
001:8G
DG
HEADSET_MIN
004:6B
DG
DG
C524
330p
IC503
A3
MEMA13
A4
MEMA8
A5
MEMA14
A6
MEMA1
A7
MEMD28
A8
MEMDQM3
A9
MEMD17
A10
MEMD30
A11
MEMD19
A12
DM
A13
DE_SPOUTP
A14
DE_HSMIP
A15
DE_DCIN2
A16
DE_MIN
A17
DE_TDO
A18
DE_TDI
B1
ATDI
B2
ATCK
B3
MEMRAS/A20
B4
MEMD31
B5
MEMD16
B6
MEMD29
B7
MEMD22
B8
MEMD26
B9
MEMD24
B10
MEMA2
B11
TRACEPKT0
B12
DP
B13
DE_SPOUTN
B14
DE_HSMIN
B15
DE_LIN0
B16
DE_MIP
B17
DE_TMS
B18
DE_TCK
C1
MEMA9
C2
MEMA11
C3
MEMA4
C4
MEMD25
C5
MEMA5
C6
MEMD20
C7
MEMA10
C8
MEMD23
C9
TRACECLK
TXA_ER
U2
ATMS
U3
TXA_EN
U4
RXDA3
U5
RXA_ER
U6
MDCA
U7
TXDB2
U8
TXB_CLK
U9
RXDB2
U10
RXB_CRS
U11
RXB_DV
U12
CGPIO19
U13
FSYNC
U14
XTALOUT
U15
AGPIO16
U16
DSP_BGPIO8
U17
DTMS
U18
DTDO
V1
ATDO
V2
DW_TEST_MODE
V3
TXDA0
V4
TXA_COL
V5
RXDA1
V6
RXA_CRS
V7
MDIOA
V8
TXDB1
V9
TXB_COL
V10
RXDB3
V11
RXB_ER
V12
DE_BGPIO6
V13
DE_BGPIO5
V14
XTALIN
V15
SYN_OUT
V16
DW_BCLK
V17
DTCK
V18
DTDI
A1
ARTCK
A2
ATRSTN
I2C_SDA
004:7C
ASICRST
004:7C
I2C_SCL
004:7C
ASICCLK
004:7C
DG
IC508
1
X1/ICLK
2
GND
6
FRSEL
7
VDD
3
S1
8
X2
4
S0
5
SSCLK
DG
DG
DG
DG
BKLT
004:8B
D501
L503
1
2
3
4
5
6
7
8
6
7
8
DG
DG
ATRSTN
ATDI
ATCK
ATDO
001:11D
ATMS
001:11D
C501
0.01u
PHY_INT
002:D3
C522
22u
C513
0.1u
C514
0.1u
C515
0.1u
C565 0.1u
C538
1u
L504
1
2
3
4
5
6
7
8
6
7
8
MIN
004:3D
HSMICINP
004:2A
HSMICINN
004:2B
X501
13.824M
Q501
C529
100p
DG
C528
100p
DG
C526
100p
C540
100p
C530
100p
DG
DG
cpu_xa5
cpu_xa5
cpu_xa1
cpu_xa6
cpu_xa1
DG
R611
NC
R529
33
R544
47k
1%
R610
0
R547
47
R622
0
R612
NC
ARTCK
R528
220
R613
10k
R530
1M
R507
1k
R608
0
R585
0
R508
10k
R639
4.7k
R614
100
R632
0
R635
0
R634
0
R506
1k
R543
47
R609
NC
R638 47k
R607
NC
3.3V
3.3V
3.3V
24V
3.3V
ST3
ST1
ST0
ST2
R504
150
L507
DG
3.3V_FLM
C558
100p
C566
100p
C562
100p
DG
3.3VA
D502
NC
L508
DG
D503
NC
CN501
1
ESD-VSS
2
DB15
3
DB14
4
DB13
5
DB12
6
7
8
9
10
11
12
13
14
15
16
17
18
IC501
1
NC1
2
A22
54
A16
55
NC5
3
A15
56
NC6
4
A14
53
*BYTE
5
A13
52
GND2
6
A12
51
Q15/A-1
7
A11
50
Q7
8
A10
49
Q14
9
A9
48
Q6
10
A8
47
Q13
11
A19
46
Q5
12
A20
45
Q12
13
*WE
44
Q4
14
*RESET
43
VCC
15
A21
42
Q11
16
*WP/ACC
41
Q3
17
RY/*BY
40
Q10
18
A18
39
Q2
19
A17
38
Q9
20
A7
37
Q1
21
A6
36
Q8
22
A5
35
Q0
23
A4
34
*OE
24
A3
33
GND1
25
A2
32
*CE
26
A1
31
A0
27
NC2
30
NC4
28
NC3
29
VI/O
R513 150
1
2
3
45
6
7
8
R514 150
1
2
3
45
6
7
8
R515 150
1
2
3
45
6
7
8
tdo
tdi
tms
tck
tck_1
tdi_1
tdo_1
tms_1
C569
1000p
DG
R533
150
C533
0.01u
DG
R536
100
L512
0
C572
0.1u
C574
22u
C525
0.1u
LCD
(6)
(5)
(7)
(3)
(3)
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