2024年3月30日发(作者：节哲彦)

]

27"LCDColorMonitor

DellD2721H

Service

Service

Service

HorizontalFrequency

30kHzto83kHz

SAFETYNOTICE

CAUTION:USEASEPARATEISOLATIONTRANSFOMERFORTHISUNITWHENSERVICING

ANYPERSONATTEMPTINGTOSERVICETHISCHASSISMUSTFAMILIARIZEHIMSELFWITHTHECHASSSAND

BEAWAREOFTHENECESSARYSAFETYPRECAUTIONSTOBEUSEDWHENSERVICINGELECTRONICEQUIPME

NTCONTAININGHIGHVOLTAGES.

1

ImportantSafetyNotice

Properserviceandrepairisimportanttothesafe,reliableoperationofallDELLCompany

viceproceduresrecommendedbyDELLanddescribedinthisservicemanualareeffectivemethods

theseserviceoperationsrequiretheuseoftoolsspeciallydesignedforthe

cialtoolsshouldbeusedwhenandasrecommended.

ItisimportanttonotethatthismanualcontainsvariousCAUTIONSandNOTICESwhichshouldbecarefullyreadin

sibilityexiststhat

soimportanttounderstandthattheseCAUTIONSandNOTIC

uldnotpossiblyknow,evaluateandadvisetheservicetradeofallconceivablewaysin

whichservicemightbedoneorofthepossiblehazardousconsequencesofeachway.

Consequently,ingly,aservicerwhousesaservice

procedureortoolwhichisnotrecommendedbyDELLmustfirstsatisfyhimselfthoroughlythatneitherhissafetynor

thesafeoperationoftheequipmentwillbejeopardizedbytheservicemethodselected.

Hereafterthroughoutthismanual,DELLCompanywillbereferredtoasDELL.

WARNING

Useofsubstitutereplacementparts,whichdonothavethesame,specifiedsafetycharacteristicsmaycreateshock,

fire,orotherhazards.

Undernocircumstancesshouldtheor

assumesnoliability,expressorimplied,arisingoutofanyunauthorizedmodificationofdesign.

Servicerassumesallliability.

FORPRODUCTSCONTAININGLASER:

IRECTEXPOSURETOBEAM.

CAUTION-Useofcontrolsoradjustmentsorperformanceofproceduresotherthanthosespecifiedhereinmayresultin

hazardousradiationexposure.

CAUTION-Theuseofopticalinstrumentswiththisproductwillincreaseeyehazard.

TOENSURETHECONTINUED

RELIABILITYOFTHISPRODUCT,USEONLYORIGINALMANUFACTURER'SREPLACEMENTPARTS,WHICHARE

LISTEDWITHTHEIRPARTNUMBERSINTHEPARTSLISTSECTIONOFTHISSERVICEMANUAL.

TakecareduringhandlingtheLCDmodulewithbacklightunit

-Mustmountthemoduleusingmountingholesarrangedinfourcorners.

-Donotpressonthepanel,edgeoftheframestronglyorelectricshockasthiswillresultindamagetothescreen.

-Donotscratchorpressonthepanelwithanysharpobjects,suchaspencilorpenasthismayresultindamagetothepanel.

-ProtectthemodulefromtheESDasitmaydamagetheelectroniccircuit(C-MOS).

-Makecertainthattreatmentperson’sbodyisgroundedthroughwristband.

-Donotleavethemoduleinhightemperatureandinareasofhighhumidityforalongtime.

-Avoidcontactwithwaterasitmayashortcircuitwithinthemodule.

-Ifthesurfaceofpanelbecomesdirty,pleasewipeitoffwithasoftmaterial.(Cleaningwithadirtyorroughclothmay

damagethepanel.)

2

icalInstruction

DELLD2721H

1

1DisassemblyProcedures:

S1

Turnoffpower

S2

Unplugexternalcablesfromproduct

S3

remove

UseaPhilips‐headscrewdriverto

(No.1~4

mechanisms.

6screwsforunlocking

No.5~6screw

screw

size=M4x5;

size=M4x10;

Torque=5~6kgfxcm.)

Torque=7.5~8.5kgfxcm

S4

Use

pull

your

outthe

finger

stand.

topushthebutton,then

25

Use

1screw

aPhilips‐

forunlockingmechanisms.

headscrewdrivertoremove

S5

(Screwsize=M3x6;Torque=4.5~6.5kgfxcm)

S6

Wedge

between

your

on

the

fingers(orplasticpicks)

monitor

thecorners

rear

ofthe

cover

bottom

andthemiddlebezel

up

toreleasetherearcover,

sideof

then

the

pull

preference

carefully

cover.

for

the

unlocking

rearcover

mechanisms

inorderofarrow

ofrear

S7

Put

the

iton

rear

aprotective

cover.

cushionandremove

S8

Use

(No.1~15

17screws

aPhilips‐head

forunlocking

screwdriver

mechanisms.

toremove

No.16~17

screw

screw

size=M3x4;

size=M3x3;

Torque=4.5~6.5kgfxcm

Torque=4.5~6.5kgfxcm.)

DELLD2721H

2

Tearoff2piecestapesand3piecesaluminum

foil(pic.7.1)

S9

DisconnectthebacklightcableandLVDScable

fromtheconnectorsofpanel(pic.7.2).

Takeoffthekeyboardfromthebezel,then

disconnectthecablefromthekeyboard

(pic.7.3).

S11

Tearoffthetape(Pic.10.1).

UseaPhilips‐head/hexagonscrewdriverto

remove7screwsand2hexagonscrewfor

unlockingthemainboardandpowerboard

(Pic.10.2and3).

Pleasemakesurescrewdrivernottouchwith

componentsonboard）

(No.1~5+7screwsize=M3x6;Torque=4.5~6.5kgfxcm

No.8~9screwsize=H4.7x5(Hexagonscrew);Torque=

4~5kgfxcm

Pic.7.1

Pic.10.1

Pic.7.2

Pic.10.2

Pic.7.3

S10

Liftupthebracketchassismoduleandputit

payattention

toESDprotection(wearESDringandsoon).

Pic.10.3

S12

TakeoffthePCBfromtheshieldingcover

andputinonaprotectorcushion.

Thendisconnectcablesfromthemainboard

andthepowerboard.

26

DELLD2721H

3

S13

Liftupthetopsideofthebezel,thenpull

downtotakeoffthebezel.

27

2024年3月30日发(作者：节哲彦)

]

27"LCDColorMonitor

DellD2721H

Service

Service

Service

HorizontalFrequency

30kHzto83kHz

SAFETYNOTICE

CAUTION:USEASEPARATEISOLATIONTRANSFOMERFORTHISUNITWHENSERVICING

ANYPERSONATTEMPTINGTOSERVICETHISCHASSISMUSTFAMILIARIZEHIMSELFWITHTHECHASSSAND

BEAWAREOFTHENECESSARYSAFETYPRECAUTIONSTOBEUSEDWHENSERVICINGELECTRONICEQUIPME

NTCONTAININGHIGHVOLTAGES.

1

ImportantSafetyNotice

Properserviceandrepairisimportanttothesafe,reliableoperationofallDELLCompany

viceproceduresrecommendedbyDELLanddescribedinthisservicemanualareeffectivemethods

theseserviceoperationsrequiretheuseoftoolsspeciallydesignedforthe

cialtoolsshouldbeusedwhenandasrecommended.

ItisimportanttonotethatthismanualcontainsvariousCAUTIONSandNOTICESwhichshouldbecarefullyreadin

sibilityexiststhat

soimportanttounderstandthattheseCAUTIONSandNOTIC

uldnotpossiblyknow,evaluateandadvisetheservicetradeofallconceivablewaysin

whichservicemightbedoneorofthepossiblehazardousconsequencesofeachway.

Consequently,ingly,aservicerwhousesaservice

procedureortoolwhichisnotrecommendedbyDELLmustfirstsatisfyhimselfthoroughlythatneitherhissafetynor

thesafeoperationoftheequipmentwillbejeopardizedbytheservicemethodselected.

Hereafterthroughoutthismanual,DELLCompanywillbereferredtoasDELL.

WARNING

Useofsubstitutereplacementparts,whichdonothavethesame,specifiedsafetycharacteristicsmaycreateshock,

fire,orotherhazards.

Undernocircumstancesshouldtheor

assumesnoliability,expressorimplied,arisingoutofanyunauthorizedmodificationofdesign.

Servicerassumesallliability.

FORPRODUCTSCONTAININGLASER:

IRECTEXPOSURETOBEAM.

CAUTION-Useofcontrolsoradjustmentsorperformanceofproceduresotherthanthosespecifiedhereinmayresultin

hazardousradiationexposure.

CAUTION-Theuseofopticalinstrumentswiththisproductwillincreaseeyehazard.

TOENSURETHECONTINUED

RELIABILITYOFTHISPRODUCT,USEONLYORIGINALMANUFACTURER'SREPLACEMENTPARTS,WHICHARE

LISTEDWITHTHEIRPARTNUMBERSINTHEPARTSLISTSECTIONOFTHISSERVICEMANUAL.

TakecareduringhandlingtheLCDmodulewithbacklightunit

-Mustmountthemoduleusingmountingholesarrangedinfourcorners.

-Donotpressonthepanel,edgeoftheframestronglyorelectricshockasthiswillresultindamagetothescreen.

-Donotscratchorpressonthepanelwithanysharpobjects,suchaspencilorpenasthismayresultindamagetothepanel.

-ProtectthemodulefromtheESDasitmaydamagetheelectroniccircuit(C-MOS).

-Makecertainthattreatmentperson’sbodyisgroundedthroughwristband.

-Donotleavethemoduleinhightemperatureandinareasofhighhumidityforalongtime.

-Avoidcontactwithwaterasitmayashortcircuitwithinthemodule.

-Ifthesurfaceofpanelbecomesdirty,pleasewipeitoffwithasoftmaterial.(Cleaningwithadirtyorroughclothmay

damagethepanel.)

2

icalInstruction

DELLD2721H

1

1DisassemblyProcedures:

S1

Turnoffpower

S2

Unplugexternalcablesfromproduct

S3

remove

UseaPhilips‐headscrewdriverto

(No.1~4

mechanisms.

6screwsforunlocking

No.5~6screw

screw

size=M4x5;

size=M4x10;

Torque=5~6kgfxcm.)

Torque=7.5~8.5kgfxcm

S4

Use

pull

your

outthe

finger

stand.

topushthebutton,then

25

Use

1screw

aPhilips‐

forunlockingmechanisms.

headscrewdrivertoremove

S5

(Screwsize=M3x6;Torque=4.5~6.5kgfxcm)

S6

Wedge

between

your

on

the

fingers(orplasticpicks)

monitor

thecorners

rear

ofthe

cover

bottom

andthemiddlebezel

up

toreleasetherearcover,

sideof

then

the

pull

preference

carefully

cover.

for

the

unlocking

rearcover

mechanisms

inorderofarrow

ofrear

S7

Put

the

iton

rear

aprotective

cover.

cushionandremove

S8

Use

(No.1~15

17screws

aPhilips‐head

forunlocking

screwdriver

mechanisms.

toremove

No.16~17

screw

screw

size=M3x4;

size=M3x3;

Torque=4.5~6.5kgfxcm

Torque=4.5~6.5kgfxcm.)

DELLD2721H

2

Tearoff2piecestapesand3piecesaluminum

foil(pic.7.1)

S9

DisconnectthebacklightcableandLVDScable

fromtheconnectorsofpanel(pic.7.2).

Takeoffthekeyboardfromthebezel,then

disconnectthecablefromthekeyboard

(pic.7.3).

S11

Tearoffthetape(Pic.10.1).

UseaPhilips‐head/hexagonscrewdriverto

remove7screwsand2hexagonscrewfor

unlockingthemainboardandpowerboard

(Pic.10.2and3).

Pleasemakesurescrewdrivernottouchwith

componentsonboard）

(No.1~5+7screwsize=M3x6;Torque=4.5~6.5kgfxcm

No.8~9screwsize=H4.7x5(Hexagonscrew);Torque=

4~5kgfxcm

Pic.7.1

Pic.10.1

Pic.7.2

Pic.10.2

Pic.7.3

S10

Liftupthebracketchassismoduleandputit

payattention

toESDprotection(wearESDringandsoon).

Pic.10.3

S12

TakeoffthePCBfromtheshieldingcover

andputinonaprotectorcushion.

Thendisconnectcablesfromthemainboard

andthepowerboard.

26

DELLD2721H

3

S13

Liftupthetopsideofthebezel,thenpull

downtotakeoffthebezel.

27