Thread
512k sweep/power supply help
ah ok I should have figure.Yes, all three terminals of the transistor are used.
The middle terminal is electrically connected to the tab.
yeah It is a cheap multimeter has worked every other time I have used it, but who knows. I will recheck it with another meter that has a diode check.
Well its when I turn it on so I can not see it, but the other day I had it opened and discharged the crt and it was just sitting there and it sparked
around C35 C36 and Q11 area that one I saw out of the corner of my eye and I could hear it.
Yeah It looks ok I do not think I have a replacement (or 4 1uf disk caps)
is this J1 you are talking about, I did test from the solder up to the yolk for continuity and they all were ok with no resistance. (The pins are not real but are nails I used that fit snug into the other side since I do not know where J1 went after it was removed from the board a long time ago) I did not think these had enough juice to ark to other parallel pins (I assume you mean ark to the corresponding connector and not to parallel pins) I could use some electrical tape to insulate them more and see if that helps.
Also should I try to find a real replacement for the C6 I made and posted about?
I put some more caps (noticed one was a bit swollen at the top not enough to notice unless I looked real close) I had in it, took out the transistor and tested it again it was good, (even the transistor tester that said it was good worked so it must not have been connecting properly)
re did some of the solder and it turned on and seems to be stable (now I have to fix the (floppy and the brightness dail on the front) and it should be useable.
Thank you everyone that posted here to help me. I feel accomplished this week (fixed a lisa and a 512k mac) I must be stuck in the 80's.
re did some of the solder and it turned on and seems to be stable (now I have to fix the (floppy and the brightness dail on the front) and it should be useable.
Thank you everyone that posted here to help me. I feel accomplished this week (fixed a lisa and a 512k mac) I must be stuck in the 80's.
Congrats! That must have taken quite a while...
Thank you, I am still going to get a new analog board as a backup since all these parts were donated from other machines, or made.
So that Q11 transistor was good after all? 
YEAH STUPID $3 MULTIMETER, IT WORKS WELL FOR THAT MUCH.
STUPID $3 MULTIMETER, IT WORKS WELL FOR THAT MUCH.
it does seem to fade slowly still but does stay on. I have a feeling its just the brightness knob as I said above. I have some knobs from the IIc monitor maybe one will work.
I actually fixed the drive today. I used silicone lubricant (the store was closed to get the lithium white lube that is suggested) but I cleaned it first (with alc.) then lubed it with the silicone cleaner/lube spray I had. I worked it in until it became mechanically sound. I also replaced the missing felt pad with one from a disk ][ drive and put it back together and read the first disk I put in it. I am going to wait on the brightness knob since I am getting a brand new analog board (along with a mouse and keyboard) and I am going to use this repaired one as a back up. I did adjust the max bright and it seems to be nice and bright (probably a bit too bright) I will adjust it later. Also I seem to be getting weird feedback from the floppy drive. It does make some cool noises though. Thanks for the links I did see the 400k drives but It seems I have fixed mine I do not know yet if the one in my lisa works but we will see when I get some disks made on my 512k. It should work great for making the disks (lisa websites state the best machines besides lisa's to make disks on are the 128k, 512k, plus since they have the 400k drive)
Are you sure you want to? The cheapest analog board on ebay now is $80.
I found a kind person to send me one for a good price with a keyboard and mouse. not nearly that much. the ones on ebay are way over priced. I was waiting for a mac plus to take one out of but a brand new one is even better.
"Brand new"?
Those do crop up on EBAY about once a year. I know because I purchased such an Apple Service part, never used before, on EBAY in the past. But they are rare. And I must say that I was simply "blessed" the day I bid on it as others clearly did not spot that auction. If they had, I certainly would have been outbid. I only paid $35 for it. But it cost me another $35 to ship to Japan.
But if you mean you are buying a "used, but good condition" analog board, you still have to beware. Because any "used" board technically could have been "abused" as well. In such a case, your situation would not be different from now, and you would still need to replace some parts. At minimum, C1 needs to be replaced on many boards.
no it was a sealed service part (had to take it out of the box to fit in the shipping one with the keyboard) I told him I would feel bad using it but I got such a good deal I could not say no and he said he just wanted it to go somewhere where it would get used.
After you replace the analog board, you should use your HD 20 and a 800k drive for a nice setup!
I have two 3rd party 800 drives and a numeric pad that I am going to put with it too. I just need to get some files on to the HD20 for making my lisa disks, the first way I tried did not work so I will have to try some others.
the new board showed up today and worked great. (I have to adjust the image a bit) I also had to shorten the mouse cable about 5 inched because of a break inside cause one of the axis not to work but now it works great. now I need to figure out how to get me disks made on one of my other macs.
Now tell me, who could have caused so much damage to your Lisa and 512k? Seems like the old owners were sadistic Windows fans or something.
well the lisa I found in a pile of free stuff one day, very lucky I may add, with some kind of sticky pop residue ALL over it, still the faint spackle of silver paint on part of it (the place I got it was used by this guy here who has a van covered with circuit boards that is probably where the Memory and Cpu boards went). the 512k was acting up and that was my fault that the analog board got stuff picked off of it. but I set it right and fixed it whats the best way to adjust the picture, is it ok to do it while it is turned on, and how should I prop it up without the case?
whats the best way to adjust the picture, is it ok to do it while it is turned on, and how should I prop it up without the case?
finally got the HD-20 to boot (Had to dig for some Low D disks for the 512k) I am going to be asking in the trading post about some new 400k disks for the 512k and lisa.
You'll be hard pressed to find 400k disks. But 800k are all you need. Just format them as 400k, since you only need 1 side of the disk. And the nice part is, should you every want to reformat them as 800k, it's a snap! You can also use 720k PC disks, if you can find them.
I figured I could use 800k disks but I was also told (in the trading post) I can use HD disks? I did not think that was possible.
You were told wrong. You cannot use HD disks.
JDW is correct -- using an HD disk is a bad idea. HD and DD media are just barely different enough to cause unreliable operation. Things get a bit better if the media have been bulk-erased (or otherwise made equivalent to a virgin floppy, not merely a reformatted one), but it's still best to avoid the trick altogether, except in emergencies, perhaps.
o you know what I have a bulk tape eraser, I was thinking of using it to see if it would revive some of my dead disks (400/800k ones) I am glad I thought the disks were different and then people told me they were not and it made it all confused.
It can get confusing, indeed, especially since not all of the information on the web is correct. Here's a quick summary:
Mac 400K/800K floppies are the same, magnetically speaking, as PC 720K floppies. The only difference is in the formatting.
400K floppies are written on one side only. Both sides are used in 800K floppies.
Mac 1.4M floppies are the same as PC 1.4M (HD) floppies. These disks have an extra hole to identify the media as HD.
Some people used to drill/melt an extra hole in 720K/800K floppies to turn them into 1.4M floppies. Reliability is poor.
Some other people have put tape over the hole in 1.4M floppies in an effort to convert them into 720K/800K floppies. Again, reliability is poor, although using a bulk eraser prior to formatting can improve performance (sometimes markedly so). It's still best simply to use true 720K floppies. Although many stores no longer carry them, they can still be obtained from a variety of online sources, so there's no compelling reason to use unreliable "conversion" methods.
although I can not seem to run disk copy from the 512k 
I have some 400k and 800k disks that do not format I will try the bulk eraser on them and see if they are useable.
I have some 400k and 800k disks that do not format I will try the bulk eraser on them and see if they are useable.