Re: Sick AppleColor composite monitor

[Rubywand <rubywand@swbell.net>]

Seedbat@webtv.net writes ...
> 
> Hello all.
> 
> The composite monitor I use with my IIc went haywire the other night.
> Though it still displays, the sides of the picture are angular and rise
> slowly, distorting the entire screen along the way.
> 
> I switched the cable, switched to another IIc, a IIe, and nothing
> changed. Of course I tried all the external adjustments as well.
> 
> When I opened it up, there was a light buildup of carbon on the inside
> of the case (a small amount) right above where the plug goes into the
> CRT (the anode?). Otherwise, everything "looked" intact and unfried.
> 
> Using an insulated tool, I tinkered with the horizontal hold and
> subhorizontal tab to try to stablize the image--no luck. Same goes for
> all the other adjustments. BTW, all the adjustments turned smoothly.
> 
> If it's any help, the monitor was made in 1986; the CRT is a Toshiba.
> 
 ....

     You've done a lot of the 'usual checks'-- like, you did not find a
scratchy control.

     Sometimes, you can cure weird problems by (with everything unplugged and
OFF) unplugging the CRT socket and re-spronging the socket pins.
("Re-spronging" is a technical term which means that you take a pointy thing
and use it to push together the pin grabber connectors in each socket hole. Use
a pointy thing with an insulated handle.)

     As you know, high voltages are likely to be present at some socket holes
and some CRT pins.  Work on an open non-conductive surface, wear goggles, avoid
touching two conductive points at once, keep heavy tools away from the CRT,
...  - for more safety tips, see
http://home.swbell.net/rubywand/Csa2MONITOR.html .

     The re-spronged socket should make firm contact with the CRT pins and may
fix the problem.


     Having stuff slip upward on the sides sounds like a vertical deflection
messup. A vertical control could be blown. (Non-scratchiness does not eliminate
a blown place or break at the edges of a contol's carbon strip.)  If a vertical
control seems to do nearly nothing when it is changed, that could be the one
which is blown.

     Another possibility is a loose or blown component in the vertical
deflection circuit. This may show as a messed up capacitor or broken resistor.



Rubywand