Recent content by TheMightyMadman

Thank you! Will diagnosed a bad video ROM (which caused the horizontal lines) and a pair of bad PALs (I'm not sure the exact symptoms that these caused), plus a couple of not-great solder joints I think (socket on UH7 at least). It's interesting because I lent another working SE/30 to test the...

I think I've got to the bottom of my SCSI boot issues! Given that both drives on the BlueSCSI were properly detected, I figured that the lack of SCSI boot could have a different cause - I read somewhere that a non-working or invalid PRAM can cause this symptom, I tried clearing the PRAM with...

Thanks Fred :) The board boots happily from floppy with an original ROM SIMM installed. I loaded a System 7.1 "Disk Tools" 1.4MB 3.5" disk, and the system prompts me to initialise two Macintosh volumes. The system recognises the 16MB RAM that I have installed, though only 7MB free, I'm not...

Thanks Fred :) Will has kindly offered to look at it for me again, which I'm very grateful for, but I wanted to do the basics myself if possible as this would mean waiting several months. Yes, I've tried an original ROM SIMM too - this doesn't give a sad Mac, but SCSI still doesn't work, so I'm...

Hi all, It's been quite some time, but I am yet again revisiting this SE/30 mainboard. Will at CayMac very kindly looked at the board for me a couple of months and got it fully running. When it arrived I didn't test it immediately (because I'm an idiot), instead I: Fitted a MACSIMM in the ROM...

Hi all, I've fitted a new 60V 3A Schottky diode at PD1 (VS-30BQ060-M3), built my own 24Vdc 2.5A PSU using the connector from one of the possibly bad Apple PSUs, and reset the PRAM using the reset button on the back of the machine, and the PowerBook is now working again! Thanks everyone for...

Hi all, I thought the external power brick was playing up as I wasn't measuring 24Vdc on the pads of the power connector on the mainboard, so I tried powering the mainboard from my current-limited benchtop PSU. I tried powering just the mainboard at 24Vdc making sure the polarity was correct...

Hi everyone, I'm in the process of trying to repair a Macintosh PowerBook 1400cs/166 for a friend of mine. When I first got it, it just clicked when power was applied, the screen didn't do anything. Since then I've replaced all of the SMD electrolytic capacitors on the mainboard, control switch...

Thanks everyone :)

Hi all, I've got a Macintosh PowerBook 1400cs/166 in for repair for a friend of mine, as it wasn't starting up. I've replaced all of the SMD electrolytic capacitors on the mainboard, control switch board, and LCD board. However, all that happens now when using the original PSU is that the...

The PWM controller IC is a three-pin TO-220 package, I think it's IC1 near the fusible resistor - mine had failed short-circuit. Something will have caused that resistor to blow, so you need to find the cause of the issue before replacing the symptom - R4 is fusible for a reason. The original...

I’m glad the thread has helped you out! Good luck with your repair. I’m sorry for forgetting to update this thread previously - after replacing both the PWM controller and fusible resistor, the PSU is working happily again!

Thank you very much, I appreciate the support and encouragement, nice work getting yours working again :) I'm back working on my SE/30 again, trying to make any slow but sure progress. Here's where I'm at now: it's making a slow, immediate "death chime", and the video RAM isn't getting reset...

Hi all, I hope you're well :) I've been continuing with this SE/30 board as and when I can, but unfortunately I'm not making much progress. Testing with a known-good ROM SIMM and four known-good RAM SIMMs in the lower bank makes no difference - the machine gives a long "chime of death", and...

Hi again :) I've swapped the original IC back into UH7, with no change in symptoms. I also have some faster GALs on order. I've also tried some additional combinations of the various RAM SIMMs in the bottom four RAM SIMM sockets, with no change in symptoms. In case it's of interest to anyone...