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Toshiba 27AF43+

SuntharAbout 3 minCRT RGB mod

Toshiba 27AF43+ CRT RGB mod

This tutorial covers the RGB mod for the below models.

  • Toshiba 27AF43
  • Toshiba 27AF44
  • Toshiba 27AF45
  • Toshiba 27AF46

img NES Adventure Island

Please also see other Toshiba AF series mods, as the instructions are more or less the same.

CRT safety

Caution

You can die doing this! So read carefully! CRT TV is not a toy. Do not open a CRT TV. If you don't have any prior knowledge about handling high voltage devices, this guide is not for you. CRT TV contains high enough voltage (20,000+ V) and current to be deadly, even when it is turned off.

READ THIS BEFORE CONTINUING

Plan of attack

READ THIS TO PREPARE

Theory

Sometimes it is nice to know the theory behind the mod. I have put this on a separate page. This shows how the various resistor values are calculated.

READ THE RGB MODDING THEORY

Service manuals

Specs

  • Tube: Orion A68QCU770X66

Schematics

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PCB

Points where the R, G, B and Blank wires should be connected are marked "X". Pink boxes show the resistors, diodes that needs to be removed.

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Performing the mod

STEP 1: Remove the following components

27AF43

Remove RGB resistors to ground

  • R141
  • R142
  • R143

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STEP 2: Connect RGB and blanking wires

Replace the jumpers, W107, W108, W112 with diodes and 0.1uF capacitor as per below image. This will help reduce RGB signal noise.

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Pay attention to the orientation of the diode and where it is placed. RGB mod will fail if correct orientation and placement is not followed.

Connect the R, G, B and blanking wires as per below picture.

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  • Brown wire = blank
  • Red wire = red
  • Blue wire = blue
  • Green wire = green
  • Yellow wire = csync
  • Organge wire = auxillary
  • Grey wire = audio right
  • White wire = audio left
  • Purple = auxillary
  • Black = common ground

STEP 3: Connect Sync, Audio and Ground wire

Connect the SIGNAL, AUDIO RIGHT, AUDIO LEFT, GROUND wires img

STEP 4: Prepare your RGB mux circuit

Below mod uses the RGB mux board. This is optional, but will make your mod easier and stable. You can also create the circuit presented in the schematics above without the board. Please also checkout the precalculated resistor values.

Buy your RGB mux board

M61283FP can handle a peak to peak voltage of 0.7 in the external RGB lines.

Depending on the RGB/OSD stock resistors your CRT has, use the below inline resistors.

TV Model27AF4x27AF4x27AF4x
RGB/OSD stock resistors3.3kΩ3.9kΩ6.8kΩ
Audio LR (R7, R8)1kΩ1kΩ1kΩ
RGB termination (R1, R2, R3)75Ω75Ω75Ω
RGB inline resistors (R4, R5, R6)470Ω560Ω1kΩ
Diode (R9)1N41481N41481N4148
Blanking Resistor (R11)shortedshortedshorted
Add diodes and 0.1uF caps inlineYesYesYes

Sample Toshiba 20AF44 RGB Mux Adapter img

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STEP 5: Attach the female SCART connector to TV

Creating a SCART cutout and mounting it is an art. I have a dedicated section for it.

How to create and mount a SCART female plug?

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Pictures

Patterns

240p SMPTE img

240p Monoscope img

240p Grid img

Set

Yoke Board img

Tube img

Back View/Neck board Board img

Capacitor list

  • C407, C406, C409, C403 are capacitors that must be replaced
  • C523, C408 are good capacitors (105C) and no need to replace
VuFLocationCurrent TempRadiusLocation Description
35100C407856.4mmDeflection
351000C4138512.7mmDeflection
501C406855.3mmDeflection
5010C409855.6mmDeflection
5022C403855.3mmDeflection
10022C430856.41mmDeflection
25022C4268512.6mmDeflection
6.32200C52310510.3mmDeflection
251000C408105Deflection
16010C864, C854858.07mmNeck Board
161000C5508510mmPower
162200C5278512.5mmPower
351000C501, C5148512.7mmPower
5010C539855.6mmPower
25330C1011858.3mmSound
251000C1004, C10098510.3mmSound
351000C10038512.7mmSound
5022C1007855mmSound
10100C9165.08mmTuner
504.7C905, C904854.2mmTuner
5010C907855.6mmTuner
16470C728858mmAV
161000C6298510mmChroma
  • C916, C905, C904 (put these caps at the bottom, if you want to install an XRGB mini adapter)

Capacitor codes and references

Capacitor CodesBoard Function
C4xxDeflection
C5xxPower
C6xx
C7xx
C8xxNeck Board
C9xxTuner
C10xxAudio

Service Menu

NUMSETTINGVALUEFIXED
00OSD25
01
02H VCO3DEFAULT
03H PHASE13
04AFC GAIN6DEFAULT
05V SHIFT2DEFAULT
06H.SIZE24
07V.SIZE31
08V.LIN20
09VS.CORR38DEFAULT
10R.DRV71
11B.DRV71
12R.BIAS142
13G.BIAS142
14B.BIAS142
15BRI.MAX150DEFAULT
16BRI.CENT83
17BRI.MIN50DEFAULT
18CONT.MAX87
19CONT.CENT64DEFAULT
20CONT.MIN16DEFAULT
21COL.MAX90DEFAULT
22COL.CENT65
23COL.MIN00DEFAULT
24TINT55
25SHARP40DEFAULT
26CB DL0DEFAULT
27CR DL0DEFAULT
28CB PED8DEFAULT
29CR PED8DEFAULT
30PARABOLA20
31CORNER33DEFAULT
32TRAPEZIU30
33LEVEL17
34SEP16
35SEP234
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