NEC NMV 1700V User manual

17-inch LCD Monitor
NMV 1700V (U170ATA)
Service Manual

CircuitDescriptionIndex
NMV1700V
1.Audiocircuit ----------------------------------------------------------------------------------------------------------------------------1
1.1Audioinput-------------------------------------------------------------------------------------------------------------------------1
1.2Audiooutput-----------------------------------------------------------------------------------------------------------------------1
2.Powersupply----------------------------------------------------------------------------------------------------------------------------1
3.Videoinputcircuit---------------------------------------------------------------------------------------------------------------------1
4.Definition converterLSIperipheralcircuit -------------------------------------------------------------------------------------1
5.Systemreset,LEDcontrolcircuit -------------------------------------------------------------------------------------------------1
6.E2PROMforPNP----------------------------------------------------------------------------------------------------------------------1
7.E2PROM----------------------------------------------------------------------------------------------------------------------------------2
8.CPUcircuit ------------------------------------------------------------------------------------------------------------------------------2
8.1Dection ofPOWERswitchstatus--------------------------------------------------------------------------------------------2
8.2Displaymodeidentification----------------------------------------------------------------------------------------------------2
8.3Usercontrol------------------------------------------------------------------------------------------------------------------------4
8.4Controlofidentification converterLSI(IC14)---------------------------------------------------------------------------5
8.5I2Cbuscontrol---------------------------------------------------------------------------------------------------------------------5
8.6PowerON sequence--------------------------------------------------------------------------------------------------------------6
8.7PowerOFF sequence ------------------------------------------------------------------------------------------------------------7
8.8ListofCPUassignments--------------------------------------------------------------------------------------------------------8
TableofContents

Page1CircuitDescription
NMV1700V
1. Audio circuit (Circuit diagramsMain PWB1/1 JACKPWB1/1)
1.1Audioinput
Theaudiosignalinputreceivedfromtheaudioinputterminal(JK011)isappliedtothepre-amplifierI006 of
2(L-CH)and 29 (R-CH)through thelow-pass filterconsisting ofR047,R049,R048,R050,C062 and C063.
Inthispre-amplifier,controlsofVolume,Balance,Bass,and Trebleareconducted.Theaudiosignalcontrolled
atthepre-amplifierisenteredinand amplifiedattheAMPI007of9(L-CH)and1(R-CH).Since then,thesignal
istotheoutputjack.
1.2Audiooutput
Theaudiosignalisoutputfromtheoutputterminal(P012)ofthejacktothespeakersystem.
2. Powersupply (Circuit daigramsMAINPWB8/10, 9/10, 10/10)
1.I322:DC-DCconverter
A5VpowersupplyforLCDmodule,CPU,and logicisgeneratedfromthe19Vsource.
2.I323:3-terminalregulator
A3.3VpowersupplyforScalerICI315,LVDSICI319,I320 isgeneratedfromthe5Vsource.
3.I330:3-terminalregulator
A3.3VpowersupplyforSDRAMICI316,I317,I318 isgeneratedfromthe5Vsource.
4.I324:3-terminalregulator
A2.5VpowersupplyforScalerICI315 isgeneratedfromthe5Vsource.
Q307,I321 ON/OFF controlforLCDModule
ON/OFF controlisperformedforpowerON/OFF and alsoforthepowersaving sequence.
3. Video inputcircuit (Circuit diagramMAINPWB4/10)
TheanalogvideosignalinputenteredfromP304,theAC-coupledvideosignalisusedtoclamptheblacklevelat
0V).
4. Definition converterLSIperipheralcircuit (Circuit diagramMAINPWB)
I315 gm5020 isthedefinition converterLSI.
Theanalog R,G,Bsignalinputenteredfromthevideoinputcircuit isconvertedintothedigitaldataofvideo
signalthrough theincorporatedA/Dconverter.Basedon thisconversion,thisdevice performsinterpolation
during pixelextension.Thesource voltageforthisdevice is3.3V,2.5Vand thesystemclockfrequencyis
24MHz.Thewithstand voltagelevelfortheinputsignalvoltageifI315 is3.3Vand 5V.
5. Systemreset, LEDcontrolcircuit (Circuit diagramMAINPWB3/10)
5.1Systemreset
Systemresetisperformedby detecting therisingand falling ofthe5Vsource voltageatI301.
5.2LEDcontrolcircuit
Green/amberislit withthecontrolsignaloftheLEDGREENand LEDAMBERsignalpin15,12 fromI306
(Circuit diagramMAINPWB2/8).
6. E2PROMforPnP(Circuit diagramMAINPWB4/10)

Page2Circ uitDescription
NMV1700V
7. E2PROM(Circuit diagramMAINPWB3/10)
DatatransferbetweenI305 (AT24 C16)and CPU(Circuit diagramMAINPWB2/8(I302)iseffectedthrough
theIICbusSCL(pin15)and SDA (pin16)ofI302.Thedatatobetransferredtoeachdevice arestoredinI305.
l I315controldata.
l OSDrelatedsetting data.
l Othercontroldataforservice menu.
8. CPUcircuit (Circuit diagramMAINPWB3/10)
I302 (87C51RD2)functionsastheCPU.
Thesource voltageforthedevice is5.0Vand thesystemclockfrequencyis24MHz.
8.1Detection ofPOWERswitchstatus
TheCPUidentifiestheONstatusofthetwopowersupplies.Theidentification ismadewhenthepowersupply
isturnedoff.Forexample,ifthepowersupplyisturnedoff withthePOWERswitch,thePOWERswitchmustbe
turnedon whenactivating thepowersupplyagain.If thepowersupplyisturnedoff by pulling outthepower
cord,thenthispowersupplycanbeturnedon by connecting thepowercord,withoutpressing thePOWER
switch.
8.2Displaymodeidentification
8.2.1Functions
(1)Displaymodeidentification
l Thedisplaymodeofinputsignalisidentifiedbasedon Table1.
l Whenthemodehasbeenidentifiedthrough themeasurementofhorizontaland verticalfrequencies,thetotal
numberoflinesisdeterminedwithaformulaof“Horizontalfrequency/Verticalfrequency=Totalnumber
oflines.“Finalidentification canbemadeby examining thecoincidence oftheobtainedfigurewiththe
numberoflinesforthemodeidentifiedfromthefrequency.Theboundarynumberoflinesineachmodeis
showninTable2.
l Whenthedetectedfrequencyifthesyncsignalhaschanged,thetotalnumberoflinesshouldbecountedeven
through it isrgeidentifiedfrequencyinthesamemode.
(2)Powersavemode.
Thispowersavemodeisassumedwhenthefrequencyofthehorizontal/verticalsignalisasspecifiedbelow.
l Verticalfrequency:50 ~86 Hz
l Horizontalfrequency:24 ~92 KHz
lVTOTAL:1200 ormore.
(3)Powersavemode.
Thepowersavemodeisassumedwhenthehorizontal/verticalsignalsareasspecifiedbelow.
l If thereisno horizontalsyncsignalinput.
l If thereisno verticalsyncsignalinput.
l If thehorizontalsyncsignalisoutsidethemeasuringrangeofgm5020.

Page3CircuitDescription
NMV1700V
l If theverticalsyncsignalisoutsidethemeasuringrangeofgm5020.
Polarity
Mode
Resolution
H-freq
(KHz)
Band Width
(MHz) H V
1. VGA 720 x 400 70Hz
31.47
28.322 -+
2. VGA 640 x 480 60Hz
31.47
25.175 - -
3. MAC 640 x 480 66Hz 35 32.24 - -
4. VESA 640 X 480 72Hz
37.86
31.5 - -
5. VESA 640 X 480 75Hz 37.5 31.5 - -
6. VESA 800 x 600 56Hz
35.16
36 + +
7. VESA 800 x 600 60Hz
37.88
40 + +
8. VESA 800 x 600 75Hz
46.88
49.5 + +
9. VESA 800 x 600 72Hz
48.08
50 + +
10. MAC 832 x 624 75Hz
49.72
57.283 - -
11. VESA 1024 x 768 60Hz
48.36
65 - -
12. VESA 1024 x 768 70Hz
56.48
75 - -
13. VESA 1024 x 768 75Hz
60.02
78.75 + +
14. VESA 1280 x 1024 60Hz 64 108 + +
15. VESA 1280 x 1024 75Hz 80 135 + +
16. VESA 1152 x 864 75Hz 67.5 108 + +
17. VESA 1280 x 960 60Hz 60 108 + +

Page4 CircuitDescription
NMV1700V
Table1
Table2thenumberofthelines,Vsyncdistinction
9.3UserControl
Indication resolution The number of the
distinction lines Distinction Vsync The fixed mode
640 x 480 487 < LINE <607 fV <63 Hz 2
63 Hz < fV <68 Hz 3
68 Hz < fV <74 Hz 4
74 Hz < fV <78 Hz 5
800 x 600 607 < LINE <777 fV <58 Hz 6
58 Hz < fV <63 Hz 7
63 Hz < fV <73 Hz 9
73 Hz < fV <78 Hz 8
832 x 624 640 <LINE -10
1024 x 768 768 < LINE <870 fV <63 Hz 11
68 Hz < fV <73 Hz 12
73 Hz < fV <78 Hz 13
1152 x 864 870 < LINE <1031 16
1280 x 960 960 < LINE <1027 17
1280 x 1024 1027 < LINE 14,15
9.3.2Functions
Controliseffectedforthepush-switchestobeusedwhentheuserchangestheparameters,inordertomodifythe
respectivesetting values.Whethertheswitchhasbeenpressedisidentifiedwiththeswitchinputlevelthatis
turned“L”.
Eachswitchinputportispulledup atoutsideofASIC
EachparameterisstoredintheEEPROM,thecontentsofwhichareupdatedasrequired.
.
Port Pin No.
I/O
Signal name
Function Remarks
GPI04
I315, M1
1MENU
EXIT/ENTER switch input
ENTER/Withdraw
from OSD
GPI05
I315, L1
1DOWN switch input ( ) key
GPI06
I315, G18
1-switch input ( ) key
GPI07
I315, G19
1+switch input ( ) key
GPI0
I302, 15
1 POWER soft power switch input ( power ) key

Page5CircuitDescription
NMV1700V
9.3.1RelatedportsofI315 and pinofI302
8.4.2Fun ction s
Majorfunction ofI315 areasfollows:
(1)Ex pansion ofthedisplayscreen.
(2)Timing controlforvarioussignaltypes.
Port Pin No. I/O Signal name Function
P3.5 17 IIICCLK IIC bus clock
P3.4 16 I/O IICDATA IIC bus data
(3)Power -supplysequence (LCDpanel).
8.5I2Cbuscontrol
8.5.1RelatedportsofI302
8.5.2I2C-control ledfun ctio ns
8.4Controlofdefinitio n converterLSII315
Pin No.
I/O
Signal name
Function
R3 IIRQ gmZan1 interrupt signal
P1 OHCLK gmZan1 serial clock
P3, P4,
R1, R2
I/O HDATA gmZan1 serial data
P2 OHFS gmZan1 serial select
8.4.1Portsrelatedtocontrol

Page6 CircuitDescription
NMV1700V
Thefollowing functionalcontrolsareeffectedby I2C.
(1)ControlofEEPROMI305fforparametersetting.
(2)Controlofaudiopreamplifier.
POWER
LED
LVCC
(Audio_EN)
Panel_VCC
PCLK/DATA
Backlight_EN

Page7CircuitDescription
NMV1700V
8.6PowerON sequence
WhenthePOWERswitchispressed,thePOWEROFFsignalisturned“H”.Whenthis“H”potentialisdetected,
theCPUbeginstoestablishtherespectivepowersuppliesaccording tothesequence shownbelow.
8.7PowerOFF sequence
WhenthePOWERswitchispressedwhilethepowersupplyisON,thePOWERONsignalisturned“H”.When
this“H”potentialisdetected,theCPUbeginstoturnoff therespectivepowersuppliesaccordingtothesequence
shownbelow.
POWER
LED
LVCC
(Audio_EN)
Panel_VCC
PCLK/DATA
Backlight_EN

Page 8 Circuit Description
NMV 1700V
Port Pin No. Signal Name Initial Setting Function Remark
~ NC ~ ~
P1.0 HDATA0 ~ gm50 0 4bit interface data
P1.1 !HDATA1 ~ gm50 0 4bit interface data
P1. "HDATA ~ gm50 0 4bit interface data
P1.3 #HDATA3 ~ gm50 0 4bit interface data
P1.4 $HCLK ~ gm50 0 4bit interface Clock
P1.5 %HFS ~ gm50 0 data enable
P1.6 &Bank ~ ~
P1.9 'PWM ~ Pulse width modulation
~ RST L Reset CPU Active H
P3.0  RXD H Receive data
~ NC ~ ~
P3.1 ! TXD H Transmit data
P3. " IRQ ~ gm50 0 interrupt signal
P3.3 # PWR_SW ~ ON/OFF monitor power
P3.4 $ SDA H IIC Bus Data
P3.5 % SCL ~ IIC Bus Data Active L
P3.6 & P3.6 H External Memor
y
Write Enable
P3.7 ' DDC_GND L Detect Dsub cable plug-in
~  XTAL ~ Crystal signal out
~  XTAL ~ Crystal signal in
~ GND ~ ~
~ ! NC ~ ~
P .0 " A8 ~ High-order address byte
P .1 # A9 ~ High-order address byte
P . $ A10 ~ High-order address byte
P .3 % A11 ~ High-order address byte
P .4 & A1 ~ High-order address byte
P .5 ' A13 ~ High-order address byte
P .6 ! A14 ~ High-order address byte
P .7 ! A15 ~ High-order address byte
~! PSEN# H Program store enable
~!! ALE ~ Address latch enable
~!" NC ~ ~
~!# EA# H External Access Enable
P0.7 !$ D7(USB_ON) H USB HUB
p
ower Enable
(
o
p
tion
)
P0.6 !% D6(MUTE) H Audio MUTE Enable
P0.5 !& D5(LVCC) L Audio suspend Enable
P0.4 !' D4(LEDGRN) H LED Green ON
P0.3 " D3
(
LEDAMBER
)
L LED AMBER ON
P0. " D (BKLT_EN) ~ Inverter Back light Enable
P0.1 " D1
(
LVDS ON
)
H LVDS IC Enable
P0.0 "! D0
(
PANEL EN
)
H Panel power Enable
~"" VCC ~ VCC
8.8 List of CPU Pin Assignments

IndexTroubleShooting
NMV1700V
1.Nodisplayofscreen(Screenisblack,colorofLEDisamber)------------------------------------------------------------1
2.Nothing displayson screen(Screenisblack,colorofLEDisgreen) ----------------------------------------------------2
3.Checkingthebacklightunit --------------------------------------------------------------------------------------------------------5
4.Abnormalscreen-----------------------------------------------------------------------------------------------------------------------6
5.AbnormalAutoadjustment----------------------------------------------------------------------------------------------------------8
5.1NO OSMdisplay------------------------------------------------------------------------------------------------------------------8
5.2OSDAdjustproblem-------------------------------------------------------------------------------------------------------------8
6.Abnormalplug andplayoperation ------------------------------------------------------------------------------------------------9
6.1AbnormalDDC2------------------------------------------------------------------------------------------------------------------9
7.Checking theinterfacecircuit ofsyncsignal--------------------------------------------------------------------------------- 10
7.1Checkingthecontrolcircuit ofhorizontalsyncpulse----------------------------------------------------------------- 10
7.2Checkingthecontrolcircuit ofverticalsyncpulse-------------------------------------------------------------------- 10
8.Checking theresolution changeICmovement------------------------------------------------------------------------------- 11
9.Nopoweron--------------------------------------------------------------------------------------------------------------------------- 12
10.Checking theDC/DCconvertercircuit----------------------------------------------------------------------------------------- 13
11.CheckingtheoperationofCPU-------------------------------------------------------------------------------------------------- 14
12.Checkingtheaudiocircuit --------------------------------------------------------------------------------------------------------- 15
TableofContents

TroubleShootingPage1
NMV1700V
1.Nodisplayofscreen (Screen isblack,colorofLEDisamber)
Does OSM display when you push
PROCEED button.
Yes
Check if the sync signal from Computer
is output and if the video cable is
connected normally.
No
Preceed "No OSM display"section.
OK
Proceed "Checking the resolution change
IC movement" section.
NG Input the sync signal of computer, or
change the cable.
When a signal isn't
being inputted, it is
indicated with "VIDEO
INPUT". It is indicated
with "OUT OF RANGE"
at the time of the
frequency that it can't be
distinguished.

Page2 TroubleShooting
NMV1700V
2.Nothing displays on screen (Screen isblack,colorofLEDisgreen)
Is backlight lit?
OK
Does computer output RGB video signals?
NG Refer "Checking the backlight unit" section
OK
Check OSM menu is displayed on screen
when you push the "PROCEED" key.
NG
1) Change pattern of video signal output on the
host.
2) Reconnect the video cable.
3) Change the video cable.
Check the video cable for failure. Check the host for
output signal with all black only.
OK NG
Proceed "Abnormal screen" section.
Check if the LCD video signal cable is connected
between the MAIN PWB and LCD module.
OK
NG
Next Page
Failure Point
The Cable is disconnected.

TroubleShootingPage3
NMV1700V
Continue
Check if the voltage on I323, I330
pin 3 that is high level DC at 5V.
Check the 3.3 V power are supplied on I323, I330 pin 2.
OK
NG
OK NG
Failure point
1) Printed wire broke between I322 and I323, I330
2) I322 failure.
Failure point
I323, I330 Failure
Is a dot clock being outputted under the
condition that a LCD module is
connected to L322 pin 2?
OK NG
Failure point
1) I315 failure
2) Printed wire broke between I315 and L322 pin 2.
Check the H-sync pulse of negative polarity
is output on RN314 pin 8 at TTL level.
OK NG
Failure point
1) I315 failure
2) Printed wire broke between I315 and RN314 pin 8.
Check the V-sync of negative polarity
are output on RN314 pin 7.
OK NG
Next Page
Failure point
1) I315 failure
2) Printed wire broke between I315 and RN314 pin 7.

Page4 TroubleShooting
NMV1700V
Continue
Check the data enable of positive polarity are output on RN314 pin 6.
OK NG
Failure point
1) I315 failure.
2) Printed wire broke between I315 and RN314 pin 6.
Check the data signal output on I315 R, G, B
data pin.
OK NG
Failure point
1) I315 failure.
Failure point
1) The cable broke between P304 and LCD
module.
2) LCD module failure.
Check I319, I320 all LVDS signal pins.
OK NG
Failure point
1) I319, I320 failure.
2) Printed wire broke between I319, I320 and P307.

TroubleShootingPage5
NMV1700V
3.Checking the back lightunit
Is +19V supplied to F301 pin 1.
OK
NG
OK
NG
Failure point
An AC adapter is changed to the normal goods.
Is +19V supplied to P308 pin 3, 4 to inverter
PWB?
OK
NG
Are connected AC adapters normal goods?
Failure point
Inverter cable disconnection.
Failure point
Printed wire broke between
P312 pin 1.
Check the BKLT_EN signal of the rectangle input I327 pin 3 at TTL high level
OK
NG Is a "H" level being output in the TTL level from I306 pin 14
Or, is BKLT_EN signal of the rectangle being output?
NG
Failure point
Printed wire broke between
I306 pin 14 and I327 pin 3.
Check the PWM signal of the input from I315 pin M4 (R374 pin 2) is a PWM signal.
OK
NG
Failure point
1) Printed wire broke between
I315 pin M4 and R374 pin 2.
2) I315 failure.
Failure point
1) Inverter cable disconnection.
2) Inverter of LCD module failure.

Page6 TroubleShooting
NMV1700V
OK NG
Failure point
1) No R, G and B video signal output from host computer. Check
computer
2) Video signal cable disconnection.
OK NG
Check the R, G, B video signal from computer input on
D-Sub R, G, B connector.
Check the R, G, B input signals on I315 pin E1, D2, C1
respectively that their level is 0.7Vp-p maximum.
Is the pulse of the TTL level being output to I319, I320
from the data line of I315?
Failure point
In the case of the Red signal. (A Green and Blue signal is the same
path, too.)
1) Printed wire broke between D-Sub(R) and I315 pin E1.
2) R339 short.
3) C359 open.
4) R337 open.
OK NG Failure point
1) Printed wire broke between I315 data line and I319, I320.
2) I315 failure.
Check the negative horizontal sync pulse output to
RN314 pin 8 from I315 pin F20 at TTL level.
OK NG
Failure point
1) Printed wire broke between I315 pin F20 and RN314 pin 8.
2) I315 failure
Check the negative vertical sync pulse output to RN314
pin 7 from I315 pin F19 at TTL level.
OK NG
Check the positive DE pulse output to RN314 pin 6 from
I315 pin F18 at TTL level.
OK NG
Check the SHFCLK OUTPUT to L322 pin 2 from I315 pin
G20 at TTL level.
OK NG
Next Page
Failure point
1) Printed wire broke between I315 pin G20 and L322 pin 2.
2) L321 open
3) C583 short
4) C590 short
5) L322 short
6) I315 failure
Failure point
1) Printed wire broke between I315 pin 73 and RN314 pin 7.
2) I315 failure
Failure point
1) Printed wire broke between I315 pin F18 and RN314 pin 6.
2) I315 failure
4.Abnormalscreen

TroubleShootingPage7
NMV1700V
OK NG
Continue
Check I319, I320 all LVDS signal pins.
Check SDRAM IC clk signal output to I318, I316, I317,
pin 35 from I315 pin T3.
Failure point
1) I319, I320 faulure.
2) Printed wire broken between I319, I320 and P307.
OK NG
Failure point
1) R396 open.
2) Printed wire broken between I318, I316, I317 pin 35 and I315 pin
T3..
3) I315 failure.
Check all Data/Address pins signal between I315 and
I316, I317, I318.
OK NG
Failure point
1) Printed wire broke between I318, I316, I317 and I315.
2) I315 failure
3) I318, I316, I317 failure.
Process "Checking the resolution change IC movement"
section.

Page8 TroubleShooting
NMV1700V
5.AbnormalOSMdisplay
OK
NG
Check the input of 3.3Vp-p pulse from I315 pin P3, P4, R1, R2, P2, P1.
Failure point
1) Printed wire broke between I315 pin P3 and I302 pin 5.
2) Printed wire broke between I315 pin P4 and I302 pin 4.
3) Printed wire broke between I315 pin R1 and I302 pin 3.
4) Printed wire broke between I315 pin R2 and I302 pin 2.
5) Printed wire broke between I315 pin P2 and I302 pin 7.
6) Printed wire broke between I315 pin P1 and I302 pin 6.
7) RN301, RN303 open/short.
Proceed "Checking the resolution change IC movement" section.
5.1NOOSMdisplay
5.2OSDAdjustproblem
OK
NG
Check the input TTL level whether was changed when pressed function keys.
Failure point
1) Printed wire broke between P302 pin 3 and I302 pin 15.
2) Printed wire broke between P302 pin 4 and I315 pin G19.
3) Printed wire broke between P302 pin 5 and I315 pin G18.
4) Printed wire broke between P302 pin 6 and I315 pin L1.
5) Printed wire broke between P302 pin 7 and I315 pin M1.
6) C322, C323, C324, C326, C327 short.
7) RN306, RN307, short/open.
8) I315 failure.
Proceed "Checking the resolution change IC movement" section.

TroubleShootingPage9
NMV1700V
6.Abnormalplug and playoperation
6.1AbnormalDDC2
Confirm the output of serial data on I312 pin 6, I310 pin 6 synchronize SCLK at TTL level.
OK
NG
Failure point
I310, I312 failure.
Failure point
1) The host machine isn't communicating in DDC2 mode.
2) The video cable may have failed or may not to have connections for DDC.
3) Between I312 pin 6 and P304 pin 15 may have failed.
4) Between I310 pin 6 and P303 pin 6 may have failed.
5) R335, R326 open.
6) Cable failure.