Recent content by Zhinü

I gave up, I ended up just finding two film caps and soldering them to the back. Everything looks good now.

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...

Do you happen to know which caps on the Lisa are used for AC rectification?

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...

I did try a music CD but the drive would spin down after 2 attempts to read it and shut off the main motor.

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.

Guess I’m looking for a 240mhz Japanese unit then!

I can confirm, this unit is the caddy loader. It seems like a later/early revision of the drives didn’t have the leaky caps.