25 Feb
2013
25 Feb
'13
1:28 p.m.
Well, not totally a black screen, just nothing on it.
When u turn the C64 on or off, the screen flickers for an instant, then
blank screen.
This particular also emits a very faint screech or whine.
I prob have a 5-pin to RCA somewhere, will scrounge some more.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Ethan Dicks
Sent: Monday, February 25, 2013 3:13 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Commodore 64 question
On Mon, Feb 25, 2013 at 3:59 PM, Cindy Croxton Electronics Plus
<sales at elecplus.com> wrote:
I have been testing my C64s today, and 1 works
perfectly, joysticks
and game, etc.
Hooked up via DIN cable to 3 RCA to Commodore color monitor,
everything is fine.
Perfect.
My questions are these:
1 of the C64 powers on, but absolutely nothing appears on the screen.
That is the most common failure mode, called "the black screen". Most
common cause is a faulty "PLA" (Programmable Logic Array). It can be
replaced with the PLA from another machine or can be burned from a blank
82S100. Second most common cause is bad DRAM - 4164s. It's usually the
PLA.
1 of the C64 has a totally different pin configuration
for the monitor
and disk drive, only 5 pins for the monitor. The FCC ID, model
number, etc. is exactly the same as the others, but these connections
are different. Any ideas?
The oldest Rev boards have a 5-pin DIN for video - the 5 pins that line up
with an 8-pin DIN carry the same signals, IIRC. They used to make a 5-pin
video cable that worked with both models. I've even used an ancient (1960s)
5-pin DIN *audio* cable with RCA breakouts, but the colors didn't match up
(IIRC, that cable was 2 black, 2 red, but I found the signals I needed in
there).
You will probably need to find/make a 5-pin DIN video cable for that one or
sell it untested.
Not sure about why you'd see a difference with the disk interface.
That should be a 6-pin-DIN on all C-64s (and VIC-20s, where it appeared
first).
-ethan
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Checked by AVG - www.avg.com
Version: 2013.0.2899 / Virus Database: 2641/6130 - Release Date: 02/25/13