From: Marko Mäkelä (marko.makela_at_hut.fi)
Date: 2002-11-10 10:21:09
On Sat, Nov 09, 2002 at 12:13:22PM -0600, David Wood wrote:
> Does this occur when the PC is -and- is not hooked to the cn232?
I didn't ask, but I think yes, it occurs in both cases. The device works
properly in port #2. I haven't measured the current consumption of the
C2N232 lately, but I think it would be in the order of some tens of
milliamperes. Connecting something to the RS-232 port shouldn't matter,
since all RS-232 contacts (except ground) are routed via a DS14C232CM or
MAX232CSE. It could still be a ground loop, but the device does work
in the other port.
On Sun, Nov 10, 2002 at 12:44:21AM -0500, William Levak wrote:
> It sounds like you have a short on the cassette port. Probably one
> of the transistors that drive the port (Q4, Q5, Q6), the voltage
> regulator (VR2), or capacitor (C70). Since the operating conditions are
> different, a marginal component may behave differently.
>
> There may also be a marginal short on the connector or circuit traces.
>
> Another, simpler possibility is that the connector does not line up
> correctly with the card edge.
Thanks for the suggestions, I'll pass them on. One thing that occurred to
me from the schematic diagram
(http://www.funet.fi/pub/cbm/schematics/computers/pet/2001N/320349-3.gif)
are the cassette jumpers. Could they have been set inappropriately?
Marko
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