1A5/Repairs: Difference between revisions
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Design mistake. The UNCAL lamp is powered by "+ | Design mistake. The UNCAL lamp is powered by "+100 V DCPLD A" which shifts the trace | ||
about 0.1 division. It should be powered from the basic + | about 0.1 division. It should be powered from the basic +100 V rail. | ||
Serial Number B124386 | Serial Number B124386 | ||
=== | ===Symptom: Vc has long asymptotic tail=== | ||
DATE: 20220520<br/> | DATE: 20220520<br/> | ||
NOTE: Old symptom, just noticed now<br/> | NOTE: Old symptom, just noticed now<br/> | ||
CAUSE: Leakage in C114, | CAUSE: Leakage in C114, 1 μF 25 V NP aluminum electrolytic<br/> | ||
ACTION: Replace with | ACTION: Replace with 1 μF 25 V X7R ceramic a la Type W<br/> | ||
FIXED | FIXED | ||
=== | ===Symptom: Clear V/CM knob skirt is cracked and slipping=== | ||
DATE: 202205<br/> | DATE: 202205<br/> | ||
NOTE: Old symptom, just slowly getting worse<br/> | NOTE: Old symptom, just slowly getting worse<br/> | ||
| Line 19: | Line 19: | ||
ACTION: Redraw with Sharpie<br/> | ACTION: Redraw with Sharpie<br/> | ||
===Symptom: Cannot pull out V/Div knob in 500 and 50 mv/div positions=== | |||
Reason: Variable V/div knob mounted too far towards the main knob. | |||
[[Category:Instrument repair reports]] | [[Category:Instrument repair reports]] | ||
Latest revision as of 06:23, 10 February 2024
Design mistake. The UNCAL lamp is powered by "+100 V DCPLD A" which shifts the trace about 0.1 division. It should be powered from the basic +100 V rail.
Serial Number B124386
Symptom: Vc has long asymptotic tail
DATE: 20220520
NOTE: Old symptom, just noticed now
CAUSE: Leakage in C114, 1 μF 25 V NP aluminum electrolytic
ACTION: Replace with 1 μF 25 V X7R ceramic a la Type W
FIXED
Symptom: Clear V/CM knob skirt is cracked and slipping
DATE: 202205
NOTE: Old symptom, just slowly getting worse
NOTE: Part #74 in mechanical diagram, 366-0418-00
ACTION: Super-glue plastic hub to metal hub
OOPS: Super glue dissolved a mark
ACTION: Redraw with Sharpie
Symptom: Cannot pull out V/Div knob in 500 and 50 mv/div positions
Reason: Variable V/div knob mounted too far towards the main knob.