Recent content by T-Man

Still pulling this one out every so often. So no charge or any activity on the screen, however, the analog/screen combination work fine when I put in a known working logic board. On start up about half of a second noise from the internal floppy, a minimal static from the speaker; nothing at...

Anyone out there with PAL/NTSC experience? I'll start by saying I'm amateur so my terminology below may not be correct. This computer is powered by a 9V DC jack. So it is not getting any type of 60 hz from the AC. The design of this ZX 128 MAX is for PAL output and I'm pretty sure that is...

Thank you. Strange but fixed. Lots of focus on the video circuit and resolution. Checked the main oscillator and it was slow. I thought there would be no way I was getting any kind of picture if this wave form was accurate. One of the caps connected to the oscillator had a trace, like...

Hello all. A bit of a shot in the dark but after buiding and then after some delay programming the ROM and FPGA I was excited to get the following screen. At first I thought this was a PAL/NTSC issue, but on the schematics the RBG output comes before the video processor (AD724JR0 IC). The AD724...

Have been getting a RaSCSI updated to PiSCSI which never did workout using a headless Pi Zero installation; not a realistic process, however did get it working by putting a Pi 3B in the mix. After removing the PiSCSI (w Pi Zero W) from the case I noted it was really hot almost to the point of...

Parts machine; have a Cutting Edge external drive and plugged the internal cable in off 1 pin; now no screen, no beep.

Yes...after removing the double sided tape on the analog board, there were a couple of broken solder joints at J1; so after reflowing, I am back to the smiley postage stamp pictured, it seems to boot based on disk drive activity but the screen remains as pictured . The screen looks about right...

Awesome thread. After looking at your recaps, rest assured, I will never be posting a picture of my recaps. Looks great.

Speaking of caps......power supply of same IIsi

Sorry if this is obvious or posted somewhere else, but I have a Macintosh plus that chimes and then HAD a small postage stamp with smiley face and no error code. After a few off and on's, it now has a thin line the width of a postage stamp in the center of the screen. It still chimes and I...

That combination worked well. Switch 7 on the one I have is broken, I believe in the off position. Right now resigned to using this SI with the BMOW ROM and move onto the power supply recap.

That was disappointing. Removed and replaced caps with electrolytics. Same behavior: white/grey screen with internal ROM, works with BMOW ROM.

Working but not as designed. Big MAYBE someone might know how to interpret this behavior. Initially, when using just like my other IIsi, no chime, no video, LED on, internal HD spins up initially but then stops. Eventually got video adapter with switches and found a video output white or grey...

Cannot remember how I ended up with this board (one of 3 nonworking SI boards I've collected over the years) but it is nonworking (no chime, no video) and has been recapped. Whenever I think of replacement by tantalum capacitors, I am looking for a positive and a negative. Are these bipolar...