Re: Lisa not powering up

hi tom,

the PSU, which clicks permanently, when pushing the start-button is in fact very likely a shortcut or something needs too much current, which is similar to a shortcut (see #3)
There is a "current-sense"-function in the PSU, which shuts off the PSU's low voltage output, if there is too much current or extremely too much current = shortcut.

first: change the PSU and try again

greetings TOM from Bavaria, the center of Europe, the country of the Alps, the marvellous castles of Koenig Ludwig and last but not least: The original Octoberfest

> several attempts should be made:
>
> 1. power button not working?
> solder two wires to the power button and shortcut them "external"
> to power up
>
> 2. psu not working?
> you own 3 Lisas, don't you? so you perhaps could switch the power
> suppy for testing
>
> 3. (I/O- or) CPU- or Mem-Card needs to much current? Or another
> part (e.g. internal hard-disk, if your Lisa has one)
> see 2 / and plug off the hard-disk
>
> 4. not reliable contact (or several contacts) between the
> motherboard and the boards?
> often the array-plugs are corroded or simply a little bended, you
> should test with a low-ohm-meter with inserted boards
> by the way: the motherboard is the horizontal board, which contains
> the plugs for mouse etc. and the reset-button and the ports.
> is this the board you mean, when you wrote "badly corroded
> motherboard "? only to be shure, that we talk about the same.
>
> 5. not reliable contact (or several contacts) between the
> motherboard and the internal plugs?
> see 4
>
> 6. not reliable contact (or several contacts) between the psu and
> the internal plugs?
> see 4
> here a picture of one of those internal plugs (don't know the right
> expression for that)
> www.scharpf-web.de/w/ProtoStecker.JPG
>
> keep me informed
>
> greetings TOM from Bavaria, the center of Europe, the country of
> the Alps, the marvellous castles of Koenig Ludwig and last but not
> least: The original Octoberfest

Am 15.01.2014 um 03:18 schrieb Tom Frikker:

> However, when I connect the drive and try to start the machine, my
> power supply clicks repeatedly as long as I hold down the button.
> Is this a voltage adjustment issue?

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