Facit 4440 TWIST, Service Instruction

Page 1: ..._ SERVICE I fx 1 4I K f _ 1 4440 TWIST VIDEO TERMINAL Editi0n 1 Pub1 N0 1160 84 14 12 1 Eng MAY 1984 K F Facit AB Service Support Department S 597 00 TVIDABERG SWEDEN...

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Page 3: ...I O N G E MICRO PROCESSOR CONTROL UNIT I DISPLAY REFRESH MEMORY SYNCHRONIZATION GENERATOR O VIDEO GENERATOR INPUT OUTPUT INTERFACE KEYBOARD SYSTEM MONITOR ASSEMBLY MONITOR CONTROL BOARD Line output s...

Page 4: ...Facit TWIST Video Terminal consist of five major physical subassemblies the Main Logic Board MLB the Data Graphic Display tube DGD the Monitor Control Boards MCB the Power Supply PSU the Keyboard KBD...

Page 5: ...ansparancy mode grounding before the connection to any data I I source is made I Power On To perform this check you need a Test gear such as Facit Text Generator or simular o iallow for a few minutes...

Page 6: ...and that the circuit board is positio ned correctly so that all keytops moves free from the top cover F 4 Access to the MLB is gained as follows Q e 1 Swltch ff the U lt a d dlSC Cf fV m the MWMWMWMWW...

Page 7: ...ECT 8k RAM W6 F R FUTURE USE SE LECT 8 k RAM W4 SERVICE USE 0NLY SEE T BLE I I 5 _____ W7 F R sv AND SE RVICE USE ON LV SEE nw___ H4 W7 TABLE TQSt EAR0MR g3e t Mode e Inhib t ece v e 2 lgna S I 1252 2...

Page 8: ...t fo ga everse mgde 5 2 1 _ USER ____ STATU 5 sw ___ 9 _____ 3 1 _ ug rtu indi rtia u cates verse if u B QCk m _v1d Da tu _ m d ode 15 tha in s dgs aand Se 1cates t in rg frmat gul i ettis 1 9 h S 0 2...

Page 9: ...erse video as a b lklg be 9 ef t 0 10 dl 9 the d SD y followed by the corresponding alpha character ff h RAM Staftlng ddP SS f0P e h of the e g Control A Hex 01 15 di5p1ayed as A _ display rows and va...

Page 10: ...t1mi 9 S15 p 9 uSi 9 8 55 and o ign amm he P rtra eneratora s req by the m d d DMU ed tu n both 2 6 VIDEQ GENEIUNT R W The Syuz 1 0 erH r 4 Creg ge t0ra 3 eg the e 9 d Out ractercharacte appropri 1sp1...

Page 11: ...R19 a b c and C17 pro terminal Main Logic Board The keyboard logic vides flashover protection for the line output 15 based 0 the 53701 mlCP0Processor used on a transistor and helps to stabilize the pi...

Page 12: ...uencies so that the lower transistor amplifies only the field frequency component of the waveform and the upper tran sistor only the line frequency component Both parabolic waveforms are taken from th...

Page 13: ...GENER L This section suggests methodes for determining which circuit is faulty in a malfunctioning unit The primary objective is to determine which sub assembly Main logic board Power supply Moni t0r...

Page 14: ...EPROM s urn on the terminal SYNC TEST basic test to verify that the CRTC he terminal will display is alive 4440 TEST MODE I O HANDSHAKE TEST this test will test the The following test modes are availa...

Page 15: ...9u w491 l 01 1 SIMl Slwo d 2 91 s SQJd SQQ V9 O 2 HO H33 1 S lwoava xo isalwoava lsglw HV3 Z 91 s SQJd HL 3Lf L_ 8 980 EL 3083 OLQ 3 lsglwv lgglwva lsglwv H L QX s SQJd F K f U LN3 1NIU f_ S __ J k x...

Page 16: ...JK JK J W f__ f r N r N 1 2 3 __ J _ PRIN NTE ___J I o J 1 K Press F6 In Landscape Mode Vertical alignment test In Portrait Mode A frame to adjust the screen geometry Press F8 In Landscape Mode Screen...

Page 17: ...y using conventional methods A faulty key switch module is not recognized during this test The figure below shows the contact arm in nonactive position With the key in active po sition the measured re...

Page 18: ...y Di Seefineet cab 1 e rn X21 from the MLB Connect a frequency coun ef S m f _ __t ter to jumper W5 adjust VR7 to 6OH Xi o sHz Z __ _ ____Jy 5 _ _ l l_s _ ___ g ii Q _V _ X _ 4b Turn the potentiometer...

Page 19: ...the Line Linearity coil for maximum 1 d d t t d If d I picture width L1 Then carefully readgust an Scape a por ra m S Vy 15 Sy this control for correct linearity between 9e met y pr b1em SUG 5 pl Ca 1...

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