#Broken A2000 Motherboard
9 messages in this thread
The CIA chips should have nothing to do with your +5v and +12v problems. The
first thing I would check is the connections to those LEDs in the Analyzer.
Those connector pins are connected to the power supply.
Do you print from the serial port? (Now that I'm replying in AP, I can't back
up and look at your original message to see whether you said.) Have you tried
running the test programs that came with the analyzer?
You should have all the schematics in the back of your A2000 manual. If not,
you can get larger versions for $30 from Software Hut, misleadingly advertised
as "Service Manual." (They are, except for size, almost identical to the ones
in the A2000 manual. A strange exception is that one pin that is called
"DACK0" in the A2000 manual is called "SHITHEAD" in the Commodore System
Schematics A2000 Rev. 6 (Nov. '91) from Software Hut!)
Lucky you got spare 8520s. I messed U300 up Saturday, so I don't get the
proper signal out of PB3 (pin 13), but I understand the only source of
replacements any more is other Amigas. 🙁
Bart
>>pin that is called "DACK0" in the A2000 manual
I have scoured the schematics in my AmigaR 2000 manual, including the AmigaR
2000 Update pages and can find no such critter. Could you point me to the
right page and location?
//daniel
\X/ AP 1.77
(Drat! I'm sure there was a "Load from Clipboard" option in my previous
version of AutoPilot. "Help" doesn't help either.) Anyway, instead of "DACK0"
I should have said "_DACK 0 at pin B19 of connector CN700 in appendix F, page 9
(F-9), showing the IBM expansion busses." Sorry for the omission.
Bart
We must have different manuals. I can't find that critter anywhere. In fact,
I can't even find CN700.
//daniel
\X/ AP 1.77
My manual is copyright 1985, 1986, 1987, nine chapters and appendices A-F.
Appendix F is Schematics, comprising 12 of them. #1, U100 (the 68000); #2,
audio, with Paula; #3, serial, with U301; #4, power (CN400) + ?; #5, memory;
#6, the Amiga expansion bus; #7, the IBM 8-bit and 6-bit expansion busses. #7
is the one I referred to.
Bart
Like I said, we must be looking at different manuals. Although the copyright
information, chapter numbering and appendix lettering is the same, the pages
within appendix F seem to be different. The pages in my Appendix F are:
F-3 U1 (68000), U6-U9, U26, U27.
F-4 U10-U11 (the 8520s), keyboard, parallel, serial, floppy connectors.
F-5 OSC 1 (28.63636 MHz) and the clock circuitry.
F-6 U30, U31, U34-U49 (DRAM).
F-7 U50 (8361 Agnus), U51-U54.
F-8 U55 (Paula), Audio, Joystick/Mouse ports.
F-9 U76 (8362 Denise), J8 (Modulator), J9 (RGB-Male).
F-10 J19 (MMU Connector), U58-U64, J20-J24.
F-11 U5 (PAL 20L8), U65 (OKI 6242B).
F-12 J25-J28 & J29-J32 (IBM buswork), J2 (Power supply distribution).
And nowhere a CN700 or Sh*thead.
Thanks anyhow. I guess if I've not had problem(s) thus far, then it's not
important.
//daniel
\X/ AP 1.77
In reference to the connector cn700 (IBM 8 bit expansion bus connector), what
information are you looking for?
// Mike COMPUSERVE: 71261,3013
\X/ (Via AutoPilot 1.77) PORTAL: MikeEgan@cup.portal.com
_DACK 0 at pin B19 of connector CN700.
//daniel
\X/ AP 1.77
Surprising differences! On my board and in my manual the 68000 is U100 rather
than U1, Paula is U200, Denise U201, etc. I didn't know the different
revisions differed that much. (I have an early Rev. 6–I recall seeing "Feb
1989" stamped someplace inside the cover.)
Anyway, it's the full-size schematics I bought as a "service manual" that have
the "****head" connection, not the user's manual.
Bart