Re: HELP Lisa dead 150W Power Supply

From: James MacPhail <uo957_at_email.domain.hidden>
Date: Thu, 27 Dec 2001 19:44:30 -0800

Hi Tom,

>unfortunately I have to notice, that the pot R11 2k Ohm is not the cause for
>that little problem I got with the power supply. As I described, I changed
>the whole part platine 99P0108-000 (where this pot is mounted on) and I'm
>still not able to start the unit.

I think Alex was suggesting that the pot be adjusted. Some Lisas won't start up because the power supply has drifted over 5.1 volts, so the crow-bar (over-voltage protection) engages, and the Lisa won't start up. In that case, you hear the tell-tale "click, click, click" but I guess you don't hear that. Alex had this problem with his Lisa and the 1.2 Amp power supply, which is a bit different as you found.

>I have the 150 V at the two 470 microfarad after the rectifier, so the unit
>could work if it wouldn't be permanently inhibited.

Perhaps you should check the safety interlock switch on the back panel?

We have needed a schematic for this (1.8 Amp) power supply for a long time... perhaps you would be willing to draw it?

Happy New Year!


James MacPhail                   "Think not of engineering as art,
uo957_at_email.domain.hidden                 but of art as engineering"
Sigma Seven Systems Ltd.
james_at_email.domain.hidden        <>

LisaList is sponsored by <> and...

Shop and save. <>

      Support Low End Mac <>

LisaList info:          <>
Send list messages to:  <mailto:lisalist_at_email.domain.hidden>
To unsubscribe, email:  <mailto:lisalist-off_at_email.domain.hidden>
For digest mode, email: <mailto:lisalist-digest_at_email.domain.hidden>
Subscription questions: <mailto:listmom_at_email.domain.hidden>
Archive: <>

Using a Macintosh? Get free email and more at Applelinks! 
Received on 2001-12-27 19:49:40

This archive was generated by hypermail 2.4.0 : 2020-01-13 12:15:19 EST