Vision If Board; Audio Board; Power Board Faults - Sinclair Microvision MTV1 Service Manual

Vision IF board

Vision smearing
No or poor vision
High gain
AGC faulty
No sync
Tuner bias incorrect
No –33V rail
High current
If the vision IF board is dead beyond resurrection (due to failure of the Sinclair chip(s)) it may still
be possible to make use of the chassis: see the later section Converting the MTV1 into a monitor.

Audio board

No detector
No audio
Distortion

Power board faults

No raster
Low or no EHT
No video
No sync
No frame
Frame faulty (inc shift)
Focus faults
Sinclair MTV1 service manual
ST1, many of coils O/C will cause smearing
L203, ST1, C201, C219, C218, C215, L205,
C214, ST2
ST1
C216, R203, R205, RV20[illegible]
C216, ST1
ST2
ST2
ST2, C213, ST1, C201, C209, C214
C305, TAA661, C307, C303, C314, C306
TBA820, R310
Ceramic filter faulty
Misalignment
ST3, TR410 S/C, D413 S/C, D421, TR401, C29,
TR409,TR406, TR407, D19
C430, C432, D411
TR491, ST3
R403, C415
D408, TR403, D409, TR402, C405, TR403,
C417
D704, RV401, R702
D410, C431
V2.1
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