Recent content by Mark_W

Ok another idea, can you test the game on an LC II running system 6.0.8? Just looked up DFAC revisions and it appears the sound chip in LC II and III is 344S1033, while in the original LC it's 343S1033. So in theory LC II and III should have the same sound right?

Ok did a quick testing on system 6.0.8 and the problem appeared, volume is very low even at 7, sounds just like @VeryVon 's on post #8. So is this a hardware issue or software issue? I assume all sound are generated by the dfac chip right? Could it be a bad chip or some damaged traces due to...

Hi all, just finished repairing a LC II last weekend and decide to chime in. The sound chip is soaked in electrolyte when I first got it, had to desolder it to clean electrolyte underneath. Anyway here's my testing result on system 7.0.1. Strangely my LC II sounds different than yours, but at...

There's one for sale on ebay right now: https://www.ebay.com/itm/326859293571 Seems like it's used to combine 4x256kb sticks into a single 1mb stick, before 1mb sticks are widely available. Don't think it's very useful today since you can easily find 1mb sticks to max it out, but still a cool...

Not necessarily since all 3 voltages come from the same transformer and they are tied together. I just measure them to confirm the other 2 voltages aren't too out of spec, otherwise there might be some issue with the transformer. As for damaged trace that's normal, every single CC I've dealt...

Yeah it's kinda tricky to do it with analog board installed, what I did is measure voltage, pull analog board out, make very small adjustment, install analog board, measure voltage again, repeat a few times and you can get the voltage spot on. For glued pp1 i just replace them with precision...

Agree with what @jonschultz said before regarding B2 voltage. Also first thing you need to do before adjusting geometry is to adjust the trimmer PP1 near the crt power supply and make sure you get 8.3V/24V/84V on secondary outputs, you can use test points labeled TP1/TP2/TP3. Usually when you do...

Have you reflowed all solder joints yet? That will rule out connection issues. if so then I guess you have the same bad transformer as I do. From my previous research, the transformer probably has a loose or cracked core which creates harmonics in the audible range, making the sizzling sound...

Ah yes I had the same issue on my LC520 (shares the same chassis as LC550/575 other than the caddy CD drive). Got the machine in non-working state and after recap it boots up but has the same buzzing/sizzling sound as yours, but much louder. Found the source to be the switching mosfet and...

I assume you are repairing the analog board of se30 right? Check -12v output of psu and on logic board. if there's no -12V you won't get any sound as the opamp used for audio amplification requires -12V. For analog board A, trace Vsync signal with an oscilloscope, make sure it reaches TDA1770...

Horizontal width is controlled by the width coil, not potentiometer. I assume you are talking about the vertical height of the image, in that case clean the height adjustment potentiometer with contact cleaner, make sure it's not damaged and is actually turning, you should see the wiper arm...

If you've already checked voltage and clock signal on Egret, then it could be a dead EGRET chip. iirc on classic ii Egret chip is surrounded by several electrolytic capacitors and it's prong to electrolyte corrosion. You can try to swap the Egret chip into another working board or compatible Mac...

Stumbled across this reset issue on an SE FDHD and made a post a while ago, it will get stuck at checkerboard pattern on powering up for ~10s, then it chimes and boots up as normal. Turns out I put a much larger capacitor at C36 by mistake when recapping, used 47uf instead of 1uf. My theory is...

Not on a se30 but I got this problem on a color classic, alternating white and dark lines are constantly moving from top of the screen to the bottom. Check the video and if you look closely you can see them crossing the bottom edge of left window at the beginning and around 3-4s. Hard to capture...

Just to add my 2 cents, I managed to fix a few conner and quantum drives with melted rubber bumper on the magnet, just wrap a few layers of Kapton tape around them and that's it. Tried to clean the goo once but made a huge mess, so never gonna try that again... For those quantum drives with...