Alright, I end up trying to do the bypass caps first.
Got two 0.1uf ceramic caps, put one bypassing CR1, the other bypassing C3 on my Apple Lisa video board.
Results: seemingly no change, there’s still a ripple through the video. Will have to see if replacing the Zener fixes it, and if not...
So i've found out that on the Apple Lisa, the way the 5v is generated causes noise/ripple on the CRT when the horizontal phase potentiometer is adjusted.
"The problem is due to poor filtering in the power supply, which couples the ripple on the 5 volt supply into the 33V supply for the video...
So I decided to try and test mine, and… yep, that’s the issue. I was turning the pot the wrong way, but with it maxed to the right side the ripple stops.
I didn’t do it from the power-supply but I did pull the video card out to see if I could see the ripple on the pins prior to them going into the video card.
With the video card removed I’m getting 0.446v of AC on vertical sync, and 12V DC has 0.010v of AC (max). This is tested with a Klein...
DosFox found one of the issues, he noticed that the 330uf cap was backwards on the board and bulged out. I don’t think this specifically is causing all of the issues but I replaced it with the original cap to at least rule that out.
All the safety caps were replaced with Kemet safety caps, the gray box ones. You can see them at the bottom of this image.
The smell seemed more electronic then like, RIFA, for lack of a better way of explaining it.
Decided to recap my Lisa recently after a couple of people told me that the 1.8A PSU + video board can suffer from bad caps. I ordered these parts, which I later found out I forgot to order a 100uf cap for the analog board (replaced it with a 100uf cap in the order and skipped one of the 100uf...
Me too bud, me too.
I checked in with the market research post on LisaList2, and got hit with the ominous “we hit some complications that may or may not be resolved eventually,” aka they probably got C&D’d or something over the files.
Recently picked up a PFG for my Lisa, going through GitHub and noticed the 2MB Card Project by Warmech. I’m curious on if there’s been any updates since initial release, and how hard is it to build one (since my Lisa currently has 2 512k cards).
Also, while scrolling through LisaList, I saw...
Totally fine, I ended up selling this unit unfortunately. I assume with great difficulty you could mod the later PPC boards into a LC575, in the same way you do a Takky mod to a Color Classic.
The thing is it doesn’t have the caps that people normally point out as leaking.
I’m wondering if the laser diode has died (or is weak and unable to read CDs).
I recently picked up a PowerBook 2400C that was upgraded to a G3/400mhz + 80mb of RAM, but was originally a (I believe) US 180mhz model. During my readings I remember hearing about modifying the 2400C to support cardbus cards, which involved cutting two wires on the board.
I went for it...
Alright, got the KXL-810A. Good news, it’s the thing I bought. Bad news, it’s not working. Plays audio CDs fine but when it’s hooked up to my PowerBook 2400, with the card it doesn’t pop up at all and directly connecting it to the SCSI bus results in the same problem except with CDT, which pops...
I believe there are a couple adjustment pots but I do want to wait till I get more advice before I start tweaking those. AFAIK these are old enough to not use belts.
Got an AppleCD SD that doesn’t seem to work. I took it apart to find that it didn’t have the usual leaky caps, however it also doesn’t seem to read CDs. Put in my Apple Legacy CD (the 7.6.1 variant) that I burned to find that it flashes the orange light up front twice before slowly spinning the...
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