| IIC dead after 30 years no boot chessmate screen [message #394731] |
Wed, 20 May 2020 10:21  |
|
|
Originally posted by: ettore.pelliccioni
Hi,
After 30 years, i bring from my parents house my lovely apple iic, i admit that a feel nostalgy on this time, and wish to show to my children this computer working again.
When i try to turn on, no boot from floppy, neither beep get video from composite out, the video show like a chessmate screen, . I test psu, seems ok, reseat chips, get out rom and cpu same behavior.
Somebody have get a similar issue before?
Thanks in advance.
|
|
|
|
|
|
|
|
| Re: IIC dead after 30 years no boot chessmate screen [message #394749 is a reply to message #394731] |
Wed, 20 May 2020 18:01  |
|
|
Originally posted by: Ettore Pelliccioni
These is a screenshot:
https://ibb.co/HGx3W3t
this image get also without cpu & rom in sockets. No reach to run auto test..
Regards.
El miércoles, 20 de mayo de 2020, 10:21:58 (UTC-4), Ettore Pelliccioni escribió:
> Hi,
>
> After 30 years, i bring from my parents house my lovely apple iic, i admit that a feel nostalgy on this time, and wish to show to my children this computer working again.
>
>
> When i try to turn on, no boot from floppy, neither beep get video from composite out, the video show like a chessmate screen, . I test psu, seems ok, reseat chips, get out rom and cpu same behavior.
>
> Somebody have get a similar issue before?
>
> Thanks in advance.
|
|
|
|
|
|
| Re: IIC dead after 30 years no boot chessmate screen [message #394752 is a reply to message #394750] |
Wed, 20 May 2020 19:30 |
|
|
Originally posted by: Frank M.
It's strange. the //c self-test does not look like that. Also odd that the 'chess board' is evenly spaced in widescreen mode (the //c is standard def ie 3:4). Are you sure it's not a problem with the tv or monitor that you're using? Some newer TVs don't like Apple's non-standard output. Could also be NTSC vs PAL?
|
|
|
|
| Re: IIC dead after 30 years no boot chessmate screen [message #394756 is a reply to message #394731] |
Wed, 20 May 2020 21:22 |
|
|
Originally posted by: James Davis
On Wednesday, May 20, 2020 at 7:21:58 AM UTC-7, ettore.p...@gmail.com wrote:
> Hi,
>
> After 30 years, i bring from my parents house my lovely apple iic, i admit that a feel nostalgy on this time, and wish to show to my children this computer working again.
>
>
> When i try to turn on, no boot from floppy, neither beep get video from composite out, the video show like a chessmate screen, . I test psu, seems ok, reseat chips, get out rom and cpu same behavior.
>
> Somebody have get a similar issue before?
>
> Thanks in advance.
I have heard that the capacitors are the first thing to go bad in hot storage!
|
|
|
|
| Re: IIC dead after 30 years no boot chessmate screen [message #394760 is a reply to message #394731] |
Wed, 20 May 2020 23:37 |
sicklittlemonkey
Messages: 570
Registered: October 2012
Karma: 0
|
Senior Member |
|
|
On Thursday, 21 May 2020 00:21:58 UTC+10, ettore.p...@gmail.com wrote:
> When i try to turn on, no boot from floppy, neither beep get video from composite out, the video show like a chessmate screen, . I test psu, seems ok, reseat chips, get out rom and cpu same behavior.
This is common. The checkerboard pattern is the power-on value of the RAM and varies from machine to machine. Power on video state is hires graphics.
No beep means the CPU is stuck, so it doesn't get a chance to switch to text mode then beep etc.
Get a logic probe (cheap, only $10-20) and start by checking the clock signal to the CPU. Oh, Mike Willegal has a list that agrees with me.
http://willegal.net/appleii/appleii-repair.htm
The trouble with fixing the //c is the LSI chips, but if it's just RAM you should be OK.
Cheers.
Nick.
|
|
|
|
| Re: IIC dead after 30 years no boot chessmate screen [message #394811 is a reply to message #394731] |
Fri, 22 May 2020 15:11 |
|
|
Originally posted by: Ettore Pelliccioni
El miércoles, 20 de mayo de 2020, 10:21:58 (UTC-4), Ettore Pelliccioni escribió:
> Hi,
>
> After 30 years, i bring from my parents house my lovely apple iic, i admit that a feel nostalgy on this time, and wish to show to my children this computer working again.
>
>
> When i try to turn on, no boot from floppy, neither beep get video from composite out, the video show like a chessmate screen, . I test psu, seems ok, reseat chips, get out rom and cpu same behavior.
>
> Somebody have get a similar issue before?
>
> Thanks in advance.
Hi, friends,
today i get borrow an old Keenwood cs-1021 20MHZ osciloscope , and can
test signals on motherboard.
I see clock signal good, 5v good but, on the CPU 65C02 see that RESET pin (40) signal on CPU always is in a low state ( 0V ). What you think ?
I remove the CPU 65C02, and still pin 40 is in low state.
Thanks in advance.
|
|
|
|
|
|
Members
Search
Help
Register
Login
Home
