Recent content by Mark_W

Good job. In your schematic you marked DL1 as BZX84-C8V2 which is a 8.2V zener diode. I also checked the schematic made by @jonschultz which marked DL1 as BZX84-B36, a 36V zener diode. Which one did you use to get it working? Also seems XC1186B does have xray protection, DL3 is fed by a sensing...

That's normal, unlike main power supply that has feedback control on the secondary, ctr power supply is regulated only on the primary side, it will fluctuate quite a bit as load changes. IIRC on standby +B is about 70-80V, so your reading is ok. Don't think xc1186b has x-ray or +B protection...

If HOT is not shorted and CRT PSU does not enter protection mode after it tried to start initially, then the fault might not be in the horizontal output stage. Did you check the main power supply and see if it works well under load? And +5V standby voltage? Also check POWER_SAVER signal coming...

Did you check your ram sticks in another mac? Or put known good rams in it? Pretty sure it's a ram issue, I had an se showing the exact screen (sad mac with alternating texts) due to a bad ram stick. Apparently ram chips can go bad after sitting in storage for a long time. Sockets can also...

Nope, without adjustment the picture is slightly compressed horizontally, vertical size remains the same. Makes sense as vertical/horizontal size is set to 512x384. To adjust aspect ratio to 560x384 I have to shrink vertical size since horizontal size is already at its maximum, so I will end up...

I do have a 520 logic board installed in a cc chassis, and I can confirm you can switch resolution to 560x384 in monitor settings: And switching to 560x384 does work, the screen shifts a bit to the left and compresses horizontally. However, the first time I tried to switch to 560x384 crashed...

I think those are jumper pads to bypass headphone detection in the 3.5mm jack: If you short them sound should be routed to the opamp for speaker output even a headphone is plugged in. Do you have sound from headphone jack? If so double check the opamp circuit, also clean the headphone jack...

I wouldn't recommend using hot air station to remove those caps. The type with yellow plastic wrapped on them will explode when exposed to heat, when they don't violently explode the rubber seal would expand out and make a mess. The other type with ratings printed on top is usually more...

Hi all, thanks so much for your input. I double checked the voltage, reseated both rom chips as well as the swim chip, problem persisted. Swapped the motherboard into an SE chassis, same issue. Then I noticed something, I put a 47uf capacitor on C36 by mistake: Which should have been a 1uf...

Hello all, I picked up an SE SuperDrive last week and been busy restoring it. Cleaned the floppy drive and replaced the eject gear, recapped the analog/logic board and the power supply (it has an astec power supply and all capacitors tested good, but replaced them anyway), also dealt with...

Never used macsd before, did a quick google search and found this picture on their website: If the scsi connector is placed at the middle of the pcb then no it won't fit in the cc, cc's scsi cable is quite short and is connected to the motherboard edge connector directly so you can't replace...

Not sure if you seen this before but someone on github already reverse engineered the motorola ic and implemented it with discrete components: https://github.com/jonschultz/colorclassic_video_processor/ If you can order custom transformers then i guess there's no problem keeping the original...

Great work Arjen and congratulations on finally releasing the project. Took a quick look at it and noticed CP12 and CP15 are swapped, 100V capacitor should be on VE (+B, 60V) rail: Also some random thoughts: Can we use modular power supply instead of relying on original design? Most parts...

Regarding other common file types: .bin: macbinary encoded file, just use stuffit expander to extract it .hqx: hexa- or octal-encoded file, can't remember exactly, extract with stuffit expander .img, .dsk: floppy images (img could also be hdd or cd images, but you can tell by the size) and...

I use minivmac if the source file is a floppy image. It emulates a black and white 68k mac (plus iirc) so not the fastest emulator to work with, but on the plus side you can accelerate it and make file operations much faster. For sit files I use basilisk II or sheepshaver and enable the option...