[comp.sys.amiga] 2002 pops

darrell.grainger@canremote.uucp (DARRELL GRAINGER) (02/09/90)

 I have the 2002 monitor (for my C128) and have experienced the pop/snap
problem. It is a problem with the design of the monitor which can be 
fixed.
 
 From the Transactor Amiga magazine, Vol 3, Issue 1, page 12:

 There is a heat sink for a voltage regulator on the side of the monitor
near the high voltage transformer. This heat sink is L-shaped metal 
plate about four inches high and five inches long. It angles at the rear
corner for about an inch along the back of the monitor.

 The heat sink has a twist metal tab (see bottom of circuit board) 
holding it to the circuit board. This tab is arcing to the ground foil 
near it. The heat sink acts as a capacitor and once it builds a big 
enough charge it arcs. The high voltage line near the heat sink is what 
causes the heat sink to act like a capacitor.
 
 Here is the solution:
 
1. Clip the shorting metal twist tab from the heat sink. The two screws 
can hold the heat sink adequately. Carefully scrape any carbon traces on
the motherboard created by the arcing.
 
2. Provide extra electrical insulation around the red HV wire. Split 
heat shrink tubing to wrap around the HV wire and use electrical tape to
completely encase the wire with extra layers of insulation.

3. Spray Koloid Clear Acrylic plastic around the wire and the high 
voltage regulator to reduce leaking from high voltage sources.

4. Use TV Corona Dope to plastic coat area of twist tab slot and the 
ground trace.

 This article by Dick Landry, New Brighton, MN

 Article shortened because I'm too lazy to type the whole thing.

Darrell
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