Recent content by codevonlux

I think I have a few spares of the oscillator (new), DM me if you need any.

I bought this one from Amazon and it is big enough to hold the minority of the SE/20 logic board on top of it. Be careful not to put SIMM area directly on it or protect the plastic tabs on the back. After the temperature reaches the setting you can just pick any PLCC easily just with a little...

16.9344 quartz is for the audio, if you change it then the sample rate like 11.025KHz/22.05KHz will change and will sound off.

It seems that you need to check more basic functions of the board. I remember you already checked all the power rails. 1. Reset signal generated by UB11, search for "Reset*" signal in your schematic and it is on pin 5 of UB11. press the reset button and see if this signal go down to 0 from 5V...

Yes, remove the ROM first. Start from A2. It should look like a clock signal since the CPU will “walk” every address sequentially. A3 will look like clock half the frequency as A2, etc. sometimes you only see a quick pulse then you should wait a while for all capacitors on the board to...

If the ROM is not running at all or not to the point start communicating through serial port, then you'll not get anything. My previous experiences using Techstep and fixing many SE/30 logic board, typically you'll hear at least a death chime. I read through this post briefly and I don't see any...

SE/30 will not boot without ASC. I tried it on multiple boards. (simasimac) 26LS30 will not prevent a boot TL071/Q1/Q2 issue will make you unable to hear the death chime if there's one from the speaker, they are audio amplifier/driver to drive internal speaker. Line-out jack should work fine...

How is the HD image in the SD card made? An image with incorrect driver inside will definitely cause this.

There are many many different versions. 2SB624-BV3 is shown in above Bomarc schematics. They are interchangeable

I only have schematic on 800K drive. Parts around stepping motor should be the same. There is nothing else between controller chip, HA13412 and the motor and you already swapped two of them. Could you check the TRK0 signal from the zero track detector? At power up the stepping motor will keep...

Did you check the switch for the ejection mechanism with a multimeter that it will actually open/short properly? I think the floppy drive need this switch to indicate the position of the eject motor, pressed by the white cam. -Yi

I recently cleaned 3 or them, one from a original 128K, one from a 512K and one from external floppy. All of them are basically working correctly after I cleaned the old grease on the stepper motor gear thoroughly, it is not obvious how thick they are until you try with a sharp twizzer tip. Make...

I still believe there is something wrong with your sense line mod in analog board. Could you take a picture on that area? For VGA Mode you have to connect Sense Line 0 and Sense Line 1 to each other, while Sense Line 2 is left unconnected. For HiRes Mode you have to connect Sense Line 0 to...

Your photo shows original LC575 resistor locations. 0ohm on R116 and no resistor on R109. It should work fine with the analog board mod. You would only need to modify those resistors, OR ResEdit to make LC575 board work with an Unmodified color classic analog board. A proper VGA mode should...

Please also check https://colourclassicfaq.com/general/vga.html. I just did the same mod last weekend without any issue. I think you might mixed the mod to the horizontal voltage (7 to 12 is vga mod) and mod to the sense lines (only isolate pin 20 is hi-res mod). I also isolated pin 25 and added...