Memotech Limited MTX 500, Service Manual

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3 If still faulty replace the Modulator.
c)
Cause of Trouble
No video output, i.e. 'fuzzy screen'
Check Point
Pal board J11 and or Modulator
Repair Method
1 Check for pulse on pin 3 of J11 or Pin 3 of
Modulator.
2 Check for short to 5v...or replace Modulator.
3 Check +12v - if absent replace 12v Regulator.
d)
Cause of Trouble
Monitor display faulty
Check Point
Pal board monitor connection cable
Repair Method
1 Check for pulse on Q6 - (2N3906 transistor) if
absent Q6 is faulty.
2 Check for loose connections on monitor cable.
3 Is 47pf present on monitor output on back
panel?
NB: BEFORE YOU START
Always check your monitor and or TV.
Always check your monitor leads and aerial leads.
MTX Service Manual