Daewoo Dtf 2950 Service Manual

							CP-850FX Service Manual 
 
Europe R&D 
10 S19 287.25 160.00 303.25 287.25 
S20 294.25 -  - 294.25 
S21 303.25 303.25 - 303.25 
S22 311.25 311.25 311.25 311.25 
S23 319.25 319.25 319.25 319.25 
S24 327.25 327.25 327.25 327.25 
S25 335.25 335.25 335.25 335.25 
S26 343.25 343.25 343.25 343.25 
S27 351.25 351.25 351.25 351.25 
S28 359.25 359.25 359.25 359.25 
S29 367.25 367.25 367.25 367.25 
S30 375.25 375.25 375.25 375.25 
S31 383.25 383.25 383.25 383.25 
S32 391.25 391.25 391.25 391.25 
S33 399.25 399.25 399.25 399.25 
S34 407.25 407.25 407.25 407.25 
S35 415.25 415.25 415.25 415.25 
S36 423.25 423.25 423.25 423.25 
S37 431.25 431.25 431.25 431.25 
S38 439.25 439.25 439.25 439.25 
S39 447.25 447.25 447.25 447.25 
S40 455.25 455.25 455.25 455.25 
S41 463.25 463.25 463.25 463.25 
 
						

							CP-850FX Service Manual 
 
Europe R&D 
11 1.3  ATSS SORTING METHOD
 
 
The TV set sweeps all the TV bands from beginning of VHF to end of UHF. The TV controlling 
software for each program checks if a VPS CNI code is transmitted (this system exists for 
German, Swiss and Austrian transmissions). 
If no VPS CNI code is found, then the system checks if a CNI code is transmitted as part of the 
teletext transmission ( Packet 8/30 format 1 and format 2). If such a code ( VPS or teletext ) is 
found and if this code is in the ATSS list, the program is automatically named. 
If the transmission does not have VPS CNI, and no teletext service is available, then there is no 
possibility of the program being automatically named. 
The programs found are then sorted in 4 groups : 
 
Group I : It contains all the programs from the selected country and named by the TV controlling 
software. Within this group the sorting order is fixed by the ATSS list. 
Group II : It contains all the programs with a strong signal strength which are not listed in group I. 
Group III : It contains all the programs with a weak signal strength which are not listed in group I. 
Group IV : If two or more programs with the same code are found, only the strongest ( or if they 
have the same level the one with the lowest frequency) is listed in group I, II or III. The others are 
listed in group IV. 
 
1.3.1 GENERAL CASE 
 
Program 
number Group Skip
1   
2 Group I  
...   
n   
n+1   
... Group II  
m   
m+1   
... Group III  
p   
p+1   
... Group IV 9 
q   
q+1   
... not used 9 
99   
0   
  
1.3.2 SPECIAL CASE 
 
Program 
number Group Skip
1   
... Group II  
m   
m+1   
... Group III  
p   
p+1   
... Group IV 9 
q   
q+1   
... not used 9 
99   
0   
 
Special case : Country selection = Others 
 
 
 
						

							CP-850FX Service Manual 
 
Europe R&D 
12  
Note : If two programs with the same name but a different code are found these two programs 
are listed in group I, II or III . 
 
The sorting order within group II, III, and IV is based on the channel frequency. The program with 
the lowest frequency is allocated the first rank in its group, and so forth until the last program of 
the group which has the highest frequency. 
 
Special case : France 
If France is selected, the TV controlling software first sweeps all TV bands with France system 
selected ( positive video modulation) and then a second time with Europe system selected 
( negative video modulation). 
 
Special case : Switzerland 
If Switzerland is selected the TV controlling software first sweeps all TV bands with Europe 
system selected (negative video modulation) and then a second time with France system 
selected ( positive video modulation). 
 
Special case : GB 
Note for satellite receiver users : Before starting ATSS turn on your satellite receiver and tune to 
“ SKY NEWS “. 
If GB is selected the TV controlling software seeks for programs only in UHF ( C21 to C70 ). The 
sorting order is : 
1 - BBC1 
2 - BBC2 
3 - ITV 
4 - CH4 
5 - CH5 
6 – NEWS (Sky News) 
 
If two or more “ identical “programs ( same name but different code e.g. BBC1 and BBC1 
Scotland ) are found the following programs in the list will be shifted up. (1 - BBC1, 2 - BBC1, 3 - 
BBC2, 4 - ITV, 5 - CH4, 6 - CH5, 7 - NEWS, ..) 
 
If one of the programs above is not found, the associated program number remains empty 
( freq.=467.25 MHz - Skip selected - no name – system = GB). 
example A : 1 - BBC1, 2 - BBC2, 3 - ITV, 4 - -----, 5 - CH5, 6 - NEWS, ... 
example B ( if 2 BBC1 found ) : 1 - BBC1, 2 - BBC1, 3 - BBC2, 4 - ITV, 5 - -----, 6 - CH5, 7 - 
NEWS, ... 
 
 
						

							CP-850FX Service Manual 
 
Europe R&D 
13 2 SAFETY INSTRUCTION
 
WARNING: Only competent service personnel may carry out work involving the testing or repair 
of this equipment. 
 
X-RAY RADIATION PRECAUTION 
 
1.  Excessive high voltage can produce potentially hazardous X-RAY RADIATION. To avoid 
such hazards, the high voltage must not exceed the specified limit. The nominal value of the high 
voltage of this receiver is 25-26 KV (20”-21”) or  26 KV (25” - 28”) at max beam current. The high 
voltage must not, under any circumstances, exceed 27.5 KV (20”), 29KV (21”), 29.5 KV (25) or 
30 KV (28). Each time a receiver requires servicing, the high voltage should be checked. It is 
important to use an accurate and reliable high voltage meter. 
2.  The only source of X-RAY Radiation in this TV receiver is the picture tube. For continued 
X-RAY RADIATION protection, the replacement tube must be exactly the same type tube as 
specified in the parts list. 
 
SAFETY PRECAUTION 
 
Potentials of high voltage are present when this receiver is operating. Operation of the receiver 
outside the cabinet or with the back board removed involves a shock hazard from the receiver. 
Servicing should not be attempted by anyone who is not thoroughly familiar with the precautions 
necessary when working on high voltage equipment. 
Discharge the high potential of the picture tube before handling the tube. The picture tube is 
highly evacuated and if broken, glass fragments will be violently expelled. 
If any Fuse in this TV receiver is blown, replace it with the FUSE specified in the Replacement 
Parts List. 
When replacing a high wattage resistor (metal oxide film resistor) in the circuit board, keep the 
resistor 10 mm away from circuit board. 
Keep wires away from high voltage or high temperature components. 
This receiver must operate under AC 230 volts, 5O Hz. NEVER connect to a DC supply or any 
other voltage or frequency. 
 
PRODUCT SAFETY NOTICE 
 
Many electrical and mechanical parts in this equipment have special safety-related 
characteristics. These characteristics are often passed unnoticed by a visual inspection and the 
X-RAY RADIATION protection afforded by them cannot necessarily be obtained by using 
replacement components rated for higher voltage, wattage, etc. Replacement parts which have 
these special safety characteristics are identified in this manual and its supplements, electrical 
components having such features are identified by designated symbol on the parts list. Before 
replacing any of these components, read the parts list in this manual carefully. The use of 
substitutes replacement parts which do not have the same safety characteristics as specified in 
the parts list may create X-RAY Radiation. 
 
 
						

							CP-850FX Service Manual 
 
Europe R&D 
14 3 ALIGNMENT INSTRUCTIONS
 
3.1 MICROCONTROLLER CONFIGURATION : SERVICE MODE
 
To switch the TV set into service mode please see instruction below. 
1 - Select PR. number 91 
2 - Adjust sharpness to minimum and exit all menus. 
3 – Within 2 seconds press the key sequence : RED - GREEN - menu 
 
The software version is displayed beside the word Service, e.g. “SERVICE V1.00”. 
To exit SERVICE menu press menu key or Std By key. 
3.2 SERVICE MODE NAVIGATION
 
Pr Up/Down remote keys   : cycle through the service items available. 
Vol -/+ remote keys   : Dec./Increment the values within range – Cycle trough option bits. 
OK key      : Toggle bits in option byte 
 
Order Item Default setting 
Note:All settings are approximate 
1 HOR CEN  -154 
2 RED GAIN  412 
3 GRN GAIN  363 
4 BLUE GAIN  380 
5 RED BIAS  226 
6 GRN BIAS  210 
7 AGC LEVEL  56 
8  G2 – SCREEN  32 
9 AFT  32 
10 AVL  OFF 
11 OPTION1  0011 1000 [0x38] 
12 OPTION2  0000 0110 [0x06] 
13 OPTION3  1111 1111 [0xFF] 
14 PARABOLA  346 
15 HOR WIDTH  -71 
16 CORNER T  -100 
17 CORNER B  -30 
18 HOR. PARAL  2 
19 V. LINEAR  16 
20 EW TRAPEZ  12 
21 S CORRECT  130 
22 VERT CENT  -14 
23 VERT SIZE  40 
24 SHIPPING  OFF 
3.3  MICROCONTROLLER CONFIGURATION : OPTION BITS 
There are three option bytes available (16 bits in all). These option bits are available from 
Service mode. First find the OPTION1 or OPTION2 control, and then use the Volume 
PLUS/MINUS buttons on the remote control keypad to locate the bits, and OK key to toggle them. 
The table below shows the two option bytes available; 
 
 
						

							CP-850FX Service Manual 
 
Europe R&D 
15 3.3.1 OPTION 1 
 B7 B6 B5 B4 B3 B2 B1 B0 
1 
TOP 
Teletext 
OFF 
FASTEXT 
(FLOF) 
OFF 
TUBE 
4:3 
Headphone 
Volume/Bal
ance control 
OFF 
Dolby 
Virtual 
OFF 
SVHS3 
disable 
0 
TOP 
Teletext 
ON 
FASTEXT 
(FLOF) 
ON 
TUBE 
16:9 
Headphone 
Volume/Bal
ance control 
ON 
Dolby 
Virtual 
ON 
SVHS3 
enable 
Tuner options 
 
00 = Philips 
01 = not used 
10 = ALPS 
11 = PARTSNIC 
3.3.2 OPTION 2 
 B7 B6 B5 B4 B3 B2 B1 B0 
1 
JVC 
remote 
control 
AVL 
control 
OFF 
PICTURE 
TILT ON 
Program 
list 
enabled 
0 
Fixed to 
‘0’ Daewoo 
Remote 
control 
AVL 
control 
ON 
PICTURE 
TILT OFF 
Program 
list 
disabled 
See table below 
3.3.3 OPTION 3 
 B7 B6 B5 B4 B3 B2 B1 B0 
1 
Local 
keyboard : 6 
keys 
OSD 
display 
“AV” in 
extern 
mode 
AV3 
Enabled
 
Full 
ATSS 
0 
Must be set to “1” for future 
compatibility 
Local 
keyboard : 5 
keys 
Must be 
set to “1” 
for future 
compatibi
lity ( See 
CP830 
NEC) 
OSD 
display 
“EXT” in 
extern 
mode 
(JVC 
only) 
AV3 
Disable
d 
(NEC 
only) 
Basic 
ATSS 
 
Beam Current 
(mA) Tube 
Nominal Max 
B2 B1 B0 
 0.95 1.10 0 0 0 
 1.00 1.15 0 0 1 
 1.05 1.20 0 1 0 
 1.10 1.25 0 1 1 
 1.20 1.35 1 0 0 
LG PHILIPS CRT 1.25 1.40 1 0 1 
SAMSUNG SDI CRT 1.30 1.45 1 1 0 
 1.35 1.50 1 1 1 
 
All values modified are immediately memorised in eeprom. 
 
						

							CP-850FX Service Manual 
 
Europe R&D 
16 3.4  TV SET ALIGNMENT
 
3.4.1  LOCAL OSCILLATOR ALIGNMENT 
Tune a colour bar pattern. The frequency of the signal carrier must be accurate ( Max +/- 10KHz 
deviation from the nominal channel frequency). 
Find “AFT” item in service mode. 
Adjust the coil L150 to bring the cursor to central position : 32. 
3.4.2 G2 ALIGNMENT 
- Tune a colour bar pattern. 
- Find the “G2 – SCREEN” item in service mode. 
- Adjust screen volume ( on FBT ) to bring the cursor to central position : 32. 
3.4.3 WHITE BALANCE 
- Select a dark picture and adjust RED BIAS and GRN BIAS to the desired colour temperature. 
- Select a bright picture and adjust RED, GRN and BLUE GAIN to the desired colour temperature. 
3.4.4 FOCUS 
Adjust the Focus volume ( on FBT ) to have the best resolution on screen. 
3.4.5 VERTICAL GEOMETRY 
Adjust V. LINEAR (linearity), S CORRECT (S. Correction), VERT SIZE (Vertical amplitude), 
VERT CENT (vertical centring) to compensate for vertical distortion. 
 
 
 
3.4.6 HORIZONTAL PICTURE CENTRING 
Adjust HOR CEN (Horizontal centre) to have the picture in the centre of the screen. 
3.4.7  EAST / WEST CORRECTION 
Adjust the PARABOLA, HOR WIDTH, CORNER, HOR PARAL, EW TRAPEZ, to compensate for 
geometrical distortion. 
 
HOR PARAL 
 
 
						

							CP-850FX Service Manual 
 
Europe R&D 
17
 
HOR WIDTH 
adjust for 93% overscan. 
 
  
PARABOLA 
 
CORNER B & CORNER T 
 
 
 
EW TRAPEZ 
3.4.8 AGC 
- Make sure option bits are correct for the tuner fitted on the chassis (See above how to change 
option bits). 
- Adjust the antenna signal level at 62 dBμV± 1 
- Tune a colour bar pattern. 
- Find the “AGC” item in service mode. 
- Press the key “OK” on the remote keypad and wait until AGC level stabilise to the optimum 
value. 
- Alternatively, use “Vol Up/Dwn” keys to adjust manually to the desired Tuner Take Over Point 
(TOP). 
 
						

							CP-850FX Service Manual 
 
Europe R&D 
18 4 IC DESCRIPTION
 
4.1  TELETEXT DECODER WITH EMBEDDED 8-BIT CONTROLLER
 
TVText Pro is a 8-bit controller based on a enhanced 8051 core with embedded teletext, On 
screen Display and TV controller functions. 
4.1.1  BLOCK DIAGRAM OF THE SDA55XX 
 
 
 
4.1.2 DESCRIPTION 
The SDA 55xx is a single chip teletext decoder for decoding World System Teletext data as well 
as Video Programming System (VPS), Program Delivery Control (PDC), and Wide Screen 
Signalling (WSS) data used for PAL plus transmissions (line 23). 
The device provides an integrated general-purpose, fully 8051-compatible Microcontroller with 
television specific hardware features. The microcontroller has been enhanced to provide 
powerful features such as memory banking, data pointers and additional interrupts etc. 
The on-chip display unit for displaying Level 1.5 teletext data is also used for customer defined 
on-screen displays. Internal XRAM consists of 16 Kbytes. Device has an internal ROM of 128 
Kbytes. 
The SDA 55xx supports a wide range of standards including PAL, NTSC and contains a digital 
slicer for VPS, WSS, PDC, TTX and Closed Caption, an accelerating acquisition hardware 
module, a display generator for Level 1.5 TTX data and powerful On screen Display capabilities 
based on parallel attributes, and Pixel oriented characters (DRCS). 
 
The 8-bit Microcontroller runs at 360 ns. cycle time (min.). Controller with dedicated hardware 
does most of the internal TTX acquisition processing, transfers data to/from external memory 
 
						

							CP-850FX Service Manual 
 
Europe R&D 
19 interface and receives/transmits data via I 2 C-firmware user-interface. The slicer combined with 
dedicated hardware stores TTX data in a VBI buffer of 1 Kilobyte. The Microcontroller firmware 
performs all the acquisition tasks (hamming-and parity-checks, page search and evaluation of 
header control bits) once per field. Additionally, the firmware can provide high-end Teletext-
features like Packet-26-handling, FLOF, TOP and list-pages. 
 
4.1.3  IC MARKING AND VERSION 
Chassis IC 
marking OSD languages ATSS countries Text  
CP850FX SDA555X
FL BULGARIAN, 
CZECH, GERMAN, 
DANISH, SPANISH, 
FRENCH, FINNISH, 
ENGLISH, GREEK, 
HUNGARIAN, 
ITALIAN, 
NORWEGIAN, 
DUTCH, POLISH, 
ROMANIAN, 
RUSSIAN, 
SWEDISH, 
SLOVAKIAN. Austria, Belgium, 
Switzerland, Czech 
Republic, Germany, 
Denmark, Spain, 
France, Finland, GB, 
Greece, Hungary, Italy, 
Ireland, Norway, 
Netherlands, Portugal, 
Poland, Sweden, 
Slovak Republic, 
Others PAN-EUROPEAN 
LATIN, CYRILLIC, 
GREEK. 
 
4.1.4 PINNING 
PSDIP 52-pin Pin Name Type Short Description 
1  SCL  IN/OUT Software driven I2C bus Clock line 
2  SDA  IN/OUT Software driven I2C bus Data line 
3  S/SW2  IN  Slow switching control for SCART 2. 
4 S/SW2 IN (See Microcontroller I/O pin configuration) 
5  S/SW1  IN  Slow switching control for SCART 1. 
6 S/SW1 IN (See Microcontroller I/O pin configuration) 
7 n.c.   
8  Reset Out  OUT  Driven by controlling software to reset video IC’s. 
9  VDD2.5  IN  Supply voltage 2.5V 
10 VSS IN Ground (0V) 
11 VDD3.3 IN Input/Output 3.3V 
12  CVBS  IN  CVBS input for the acquisition circuit 
13  VDDA2.5  IN  Supply voltage for analog components 
14  VSSA  IN  Ground for analog components 
15  AFT  IN  ADC input, AFT input 
16  AGC  IN  ADC input, for AGC alignment only 
17  KEY  IN  ADC input, local key sensing 
18 OCP IN Switch Off the set when the voltage goes below a 
trigger level 
19 HS IN Horizontal sync for OSD/Txt synchronisation 
20  VS  IN  Vertical sync for OSD/Txt synchronisation 
21 MODESW OUT High : Negative video modulation (B, G, D, K,I) 
Low : Positive video modulation (L / L’) 
22  L/L’  OUT  High : L’, Low : L