LG 19LV2300 (CHASSIS:LA86D) Service Manual ▷ View online
- 21 -
A SMPTE Color bar signal is recommended for this
trouble shooting.
Check JK701, JK707
an you see the normal waveform?
Refer to figure 1
JK701,JK707 may have problem. Replace this Jack.
These points art applied connonly about all video input.
This board has big problem because Main chip(BCM3553) have some
troubles.
After checking thoroughly all path once again, You should decide to
replace BCM3553 or not.
Check the input (Pin AN17,AM19) of BCM3553(IC100).
Measure waveform at C651,C652 because it
’s more easy to
check.
Can you see the normal waveform?
This board has big problem because FRC chip(MT8280FG) have
some troubles.
After checking thoroughly all path once again, You should decide
to replace FRC-9459M.
Although you replace it, you cannot see normal display, decide to
replace Main chip(BCM3553)
Check all power domain of MT8280FG (IC1000)
(MT8280_CORE_1.0V,MT8280_DVDD33,MT8280_AV33,
AVDD12, AVDD12_SYSPLL,AVDD12_DMPLL,
AVDD12_MJCPLL,MT8280_DDRV) & crystal output (X1200 /
27MHz)&FRC_RESET Measure Power & waveform at C1224,
L1207, L1208, C2213, C1236,L1209~L1211&C1290&R410
because it
’s more easy to check.
Can you see the normal waveform?
AV-VIDEO
YES
YES
Figure 1
YES
NO
NO
- 22 -
A SMPTE Color bar signal is recommended for this
trouble shooting.
Check Luminance & Chroma signals at JK701
Can you see the normal waveform? Refer to figure 1
Replace JK701
These points art applied connonly about all video input.
Check the input (Pin AL16,AL17) of BCM355x(IC100).
Measure waveform at C651,C652 because it
’s easier to check.
Can you see the normal waveform?
S_Video-VIDEO
YES
YES
Figure 1
YES
NO
NO
Replace IC100
YES
Check all power domain of MT8280FG (IC1000)
(MT8280_CORE_1.0V,MT8280_DVDD33,MT8280_AV33,AVDD
12,AVDD12_SYSPLL,AVDD12_DMPLL,AVDD12_MJCPLL,MT8
280_DDRV) & crystal output (X1200 / 27MHz)&FRC_RESET
Measure Power & waveform at C1224, L1207, L1208, C2213,
C1236, L1209~L1211&C1290&R410 because it
’s more easy to
check.
Can you see the normal waveform?
This board has big problem because Main chip(BCM3553) have some
troubles.After checking thoroughly all path once again, You should decide
to replace BCM3553 or not.
This board has big problem because FRC chip(MT8280FG) have
some troubles.
After checking thoroughly all path once again, You should decide
to replace FRC-9459M.
Although you replace it, you cannot see normal display, decide to
replace Main chip(BCM3553)
- 23 -
A SMPTE Color bar signal is recommended for this
trouble shooting.
Check JK700,JK702.
Can you see the normal waveform? Refer to figure 1
JK700,JK702 may have problem.
Replace this Jack.
These points art applied connonly about all video input.
Check the input (Pin AL21,AM21,AN21 and PinAN22, AL22, P22)
of BCM3553(IC100).
Measure waveform at C638,C639,C640 and C628, C629, C630
because it
’s more easy to check.
Can you see the normal waveform?
Component-VIDEO
YES
YES
Figure 1
YES
NO
NO
Check all power domain of MT8280FG (IC1000)
(MT8280_CORE_1.0V,MT8280_DVDD33,MT8280_AV33,
AVDD12,AVDD12_SYSPLL,AVDD12_DMPLL,
AVDD12_MJCPLL,MT8280_DDRV) & crystal output (X1200 /
27MHz)&FRC_RESET Measure Power & waveform at
C1224,L1207,L1208,C2213, C1236,L1209~L1211&C1290&R410
because it
’s more easy to check.
Can you see the normal waveform?
This board has big problem because Main chip(BCM3553) have some
troubles. After checking thoroughly all path once again, You should
decide to replace BCM3553 or not.
This board has big problem because FRC chip(MT8280FG) have
some troubles.
After checking thoroughly all path once again, You should decide
to replace FRC-9459M.
Although you replace it, you cannot see normal display, decide to
replace Main chip(BCM3553)
- 24 -
A SMPTE Color bar signal is recommended for this
trouble shooting(1920*1080/59.934Hz).
Since the waveform of the RGB input is logical, you
may use any pattern.
Check JK705. .(pin no. 1(R)/2(G)/3(B)
Can you see the normal waveform?
Refer to figure 1
JK705 may have problem.
Replace this Jack.
These points art applied connonly about all video input.
Check the input (Pin AK16,AN15,AM15,AH16,AJ16)of
BCM355x(IC100).
Measure waveform at C635,C636,C637 and R755,R758 because
it
’s more easy to check.
Can you see the normal waveform? Refer to figure 1
RGB PC-VIDEO
YES
YES
Figure 1
YES
NO
NO
Check all power domain of MT8280FG (IC1000)
(MT8280_CORE_1.0V,MT8280_DVDD33,MT8280_AV33,
AVDD12,AVDD12_SYSPLL,AVDD12_DMPLL,
AVDD12_MJCPLL,MT8280_DDRV) & crystal output (X1200 /
27MHz)&FRC_RESET Measure Power & waveform at
C1224,L1207,L1208,C2213, C1236,L1209~L1211&C1290&R410
because it
’s more easy to check.
Can you see the normal waveform?
This board has big problem because Main chip(BCM3553) have some
troubles. After checking thoroughly all path once again, You should
decide to replace BCM3553 or not.
This board has big problem because FRC chip(MT8280FG) have
some troubles.
After checking thoroughly all path once again, You should decide
to replace FRC-9459M.
Although you replace it, you cannot see normal display, decide to
replace Main chip(BCM3553)
Figure 2
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