Re: Lisa 2/5 I/O board troubleshooting.

I have the exact same problem. My computer boots when power is turned on. I don't have to press the power button. I always get the COPS chip error. I have replaced the COPS socket, and chip. I also checked all of the tracings, and could not find any broken ones. I replaced the resistor that you had a broken tracing on to see if it would help, but no luck. The tracing on mine is good.

On Monday, October 23, 2017 at 9:11:05 PM UTC-7, compu_85 wrote:
>
> Hi,
>
> I just got a 2nd Lisa, a 2/5. The prior owner got the system in 1997. At
> that time he removed the battery, and then packed it away... and didn't
> touch it for 20 years.
>
> The system does not power up with the original I/O card. There was some
> light corrosion on the board in the battery area, I scrubbed it with some
> water and vinegar and things are much cleaner now.
>
> If I remove the COPS chip, the system powers up as soon as the power cord
> is plugged in. If I put in the I/O card from my 2/10 the power button
> responds normally and the system seems basically functional, though the
> built in parallel port doesn't see an attached disk.
>
> Here's some pointers James gave several years ago:
>
> "If you've found the power switch signal is reaching the COP421 at pin
> 20, but it isn't turning on the power: check the COP has power (pin 9
> should be approx. 5V), and check it is not held reset (pin 4 not
> below 2.5V), and that pin 1 is truly connected to ground.
>
> If you have a moderately high impedance probe, check the COP
> oscillator is running (approx. 3.9 MHz at pins 2,3). If not, check
> the parts/circuit connected to pins 2 & 3.
>
> If it all looks good, and the COP oscillator isn't running or pin 24
> still refuses to switch, then the COP might be bad, but triple-check
> it is making good contact in the socket. "
>
> If I put the COP from the 2/5 on my 2/10 I/O card, and put the card in the
> 2/5 it powers up normally. The mouse doesn't work though.
>
> I verified all pins on the COP are connected... no broken traces and the
> chip socket contacts seem ok.
> The COP has +5V on pin 9, reset on pin 4 comes up to 5V when the PSU is
> plugged in, ground on 1 is OK. The power button signal is getting to pin
> 20.
>
> My Fluke 115 can't measure frequencies of ~ 2mhz. Pin 20 has about .15v on
> it, and doesn't change when the power button is pressed.
>
> Any suggestions of where I should look next?
>
> Thanks!
>
> --
> Jason Perkins
> 313 355 0085
>

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