Samsung SGH 600, Service Manual

Page: 21 / 74

5. Troubleshooting
5-1 Main Set
5-1-1 RX Sensitivity Problem
Samsung Electronics 5-1
RX ON (RF Input - Frequency : CH Freq. + 20 kHz
- RF Amplitude : - 50 dBm)
U204 Input
≥
-60 dBm?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
F200 Input
≥
-60 dBm?
Q200 pin 1
≥
-65 dBm?
Q200 pin 3
≥
-50 dBm?
F101 Input
≥
-50 dBm?
U102
Input (pin47, 48)
≥
-55 dBm?
U102 pin 42, 43
≥
-50 dBm?
F100
pin 4, 5
≥
-50 dBm
(225 MHz)?
U102
pin 38, 39
≥
-55 dBm
(225 MHz)?
U102 pin 36, 37
≥
-45 dBm (45MHz)?
U102
pin 25, 26, 27, 28 30
mVp_p(20KHz)?
U411 pin 7, 14
1Vp_p(20KHz)?
Check U204, J401, C223
Solder Status
k
Resolder
Check U109, U204, C224, F200
Solder Status
k
Resolder
Check C219, L205, C217, C218, C216,
R219 Solder Status
k
Resolder
Q200, C216 Resolder or Replace
Check L207, L206, R221, C220, C170,
F101 Solder Status
k
Resolder
Resolder C172, L104, C171
Check U102 (pin 42, 43, 44, 47, 48),
R107, R109, C925, U839, C926, R504
Resolder or Change
Check C168, C167, C164, R137,
F100, C169, L108, L106, R138
Solder status
k
Resolder
Check C160, C159, C161, C162,
L105, L204
k
Resolder or Charge
Check U102, C164, L161
Solder status
k
Resolder
Resolder or Check U102, C124,
L101, C119, R112
k
Resolder
U411, C464, C445, L403, R466, L404,
R465, R462, R468, R443, R445, R444,
L401, L402, R447
k
Resolder