Help with parts on an apple lisa 2/5 power supply

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Last seen: 15 years 11 months ago
Joined: May 14 2006 - 14:16
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Help with parts on an apple lisa 2/5 power supply

I have tested the parts I could. some other ones have not been tested but I suspect they do not work. the fallowing numbers are in reference to (1.2amp)
I would like if someone could direct me to a good place to get these in the usa and what the equivalent catalog number would be. Im not that good with some of these parts, I am usually just used to electrolytic caps and plain resistors, some of these parts Im not familiar with and don't want to get the wrong type of cap or etc. I know this is kinda a dumb question but I don't put it past myself to mess something simple up.


Thank you for all your help

pmjett's picture
Last seen: 5 years 6 months ago
Joined: Sep 4 2005 - 22:47
Posts: 181

What laundry list. I don't see anything weird in here, although I haven't found c26 on the schematic yet. Maybe that's the admantium widget. You've got scads of places in the US that you might order these parts. I happen to like Mouser Electronics, but Digi-key is just as good. It pays to compare between the two, as prices vary.

here's the parts in a nutshell. I'm not an EE, so these are my best guesses from tinkering with stuff.

c1-c4 metalized film polyester caps will work great. I'd pick ones with as high a temp range as you can get, and obviously 250 WV or higher. Whatever you can physically fit on the circuit board
An example mouser part number: 5989-400V.22-F (0.22 uF 400V)

R8 without looking at the board you have, you could use anything that will physically fit that has 2W or higher power rating. Vitreous enamel and silicon wirewound, metal oxide, etc.
example mouser part: 283-0.5-RC (0.5 ohm, 3W metal oxide)

CR2: 400V 15A triac, the "exact" replacement is available through
Digi-Key. Mouser has similar triacs. I found a 511-BTB16-600B (600V, 16A) that should work- the other specs look close.
Digi-key part number: MAC15A6OS-ND

R14,15 I see no reason why 1/2W carbon film resistors won't work here
Mouser example: 660-CF1/2L913J

C7 good ol' electrolytic capacitor. Pick a higher WV if you have room, and the best temp range you can get. Look at the datasheets (accessible directly from search results at either vendor) to determine if the part is going to fit.
Mouser example: 140-HTRL35V1000-RC or 140-XRL35V1000-RC

C25,C30,C32,C34,C35 again, without looking at the supply, I'd say go for metalized film polyester caps
Mouser example part: 5989-250V.1-F (0.1uF 250V)

I can't find C26. I've looked several times. Generally, replace it in kind as far as type. So, if it's a ceramic disc (as in flat brown disc-thingy) then use that. If looks like a flat vitamin, go for the polyester film. Obviously if it's electrolytic (and shown polarized on the schematic) use that. If you know where it is on the schematic, then read off the specs and go for it.

I think that Mouser's search is a little more intuitive, just start clicking the general part description; remembering that resistors, caps, etc are general called "passive components" on their site. Then it narrows to a parametric selection. Digi-key (for me) seems to work better if you just type some basic description words into the search box, and then click your way to a parametric selection. So I typed "0.1 metal capacitor" into their search box and got a selection for polyester film or polypropylene film, clicked on polyester and then I had a parametric selection from there. YMMV.

Hope this is a start. I'd like to hear next week that you have a working Lisa switching power supply!


Last seen: 15 years 11 months ago
Joined: May 14 2006 - 14:16
Posts: 24
Thank you so much this is so

Thank you so much this is so much help I just wanted to double check with someone. I have had a hard time finding them so I figured I might be looking in the wrong spot.

Last seen: 15 years 11 months ago
Joined: May 14 2006 - 14:16
Posts: 24
hmm i must have missed somthing testing earlier

After some more testing I found that the power might be good I did replace 6 caps. Now I have to figure out what is wrong. when I turn on my lisa the light now comes on everytime, never happened before. but no beep or picture. I have tried two different cpu boards and two different mem boards. No picture on the external connected monitor. Earlier tonight I did see a white flash or two on the monitor so I think that the tube on the monitor is still good. Could the video card ( the one behind the picture tube) need fixed? any sugestions? On a side note someone I have been in contact with might have a lisa still in a box hardly used if at all. don't know what model or anything but might be getting it Smile if they are not trying to pull my leg Smile


Last seen: 3 years 3 months ago
Joined: Feb 22 2021 - 20:03
Posts: 1
Apple lisa power supply parts

I need some help in find a replacement part for c23 and c24 on the power supply mother board?  I will attach a picture below.

macnoyd's picture
Last seen: 1 day 7 hours ago
Joined: Oct 15 2012 - 08:59
Posts: 839
About as cheap as you'll find ...

About as cheap as you'll find, assuming it's a 3 watt.

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