Goblin intervention

Resume

Reference overhaul case on an M645 1000s, with diagnosis shifted from electronics to a mechanical lever-return cause.

Symptomes

On arrival:

• Whatever shutter speed was selected, the cycle happened almost all at once.
• The curtains seemed to leave nearly together.
• Bulb / B did not work.
• The body was unusable as received.

After an initial partial electronic repair:

• A small percentage of releases still ended in immediate closing.
• The problem sometimes appeared after rest.
• The problem sometimes appeared on the second release.
• Behavior was intermittent, and therefore misleading.

Diagnostic

Work done before the final diagnosis:

• replacement of C2: 470 uF / 6.3 V
• replacement of C1: 2.2 uF tantalum
• solder rework on an old and fragile PCB
• repair of a ground link via strap / bridge to a ground screw
• cleaning of accessible contacts

Intermediate conclusion: the C1 / C2 recap and electronic rework were necessary, but they did not explain the last failures by themselves.

Accepted root cause: a mechanical return issue on a small lever in the MS clutch / 1st curtain brake area.

Actions

Targeted cleaning with naphtha essence F, using a toothpick, cotton swab, and lint-free paper.

Useful sequence:

1. Dissolve old residue.
2. Operate the mechanism.
3. Absorb residue.
4. Repeat until the lever returns dry and sharply.

Critical point: a misplaced micro-drop of oil in this area made sticking worse; do not oil randomly in the clutch / brake area.

Resultat

Goblin is now considered a trusted body, usable without special reservation unless a new symptom appears.

A retenir

• The hard problem was not a mysteriously dead electronic component.
• The real final cause was dirty / sticky return mechanics.
• If a similar symptom appears again, the first area to revisit is the small lever in the MS clutch / 1st curtain brake area.