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It does operate to some extend but is unstable, does not work from battery power only and shuts down with a fully loaded battery if I unplug the adapter. So I guess the PMU is monitoring the +12 volts line as reference for it's battery level indicator and shutdown when it becomes too low but...

What's the best way to solder the new SMD chip in place if you don't have a rework station ? Every pin by hand under a large magnifying glass or is there an easier way ?

I've got an SE/30 logic board from a fellow collector for repair, actually recap only but they apparently send me the hopeless cases. It was dead, no video and no sound/chimes at power on, no simasimac too. I recapped the board and checked all the traces to the capacitor. No result: it does...

The Dxx chips are at the back of the PCB under the Ram modules. Anyway, I have checked the complete SCSI chip against the 3x Jpeg files, which are very detailed, and the conclusion is: there are no broken traces or VIA's. For that board I'm 90% sure the SCSI chip self is faulty. It noticed in...

I recapped a Mac Portable a few days ago but it's having power issues on the +12 volts line. All SMD caps have been replaced, the radials and axials too. It works but not from a fully charged rebuild battery. However when I plug in the power adapter, together with the battery, it does boot...

It need to be a 3,9Uf High Frequency Bi-Polar capacitor of at least 100 volts. As far as I know the only alternate on the market is the Panasonic ECW-F2395JA film capacitor. I used it in my all recaps and works perfect, fitting is just a bit of an issue. No glue need: I actually remove all...

I found a much more detailed schematics for the SCSI traces after digging through the Forum. See the 3 Jpegs at top of the page below. http://68kmla.org/forums/viewtopic.php?f=29&t=19390 Check on page 2. For Pin 20 of the SCSI chip there’s a trace to Pin #2 ( D19 ). Same for Pin 21 to...

I checked all the pins of the SCSI chip, these are fine. However I didn't check every single pin of all the VIA's as this would take many hours. I'm going to give up the board.

I used my own working SE/30 to test the hard drive. It's definately not the hard drive or the formatter. I tried multiple drives with Apple HD SC 7.3.5 and also FWB 2.0.6: both work fine in my good SE/30 when doing exactly the same, while they don't with the "problem" board. Also the working...

2x problems: I don't have a replacement SCSI chip, neither do I have a hot air rework station for removing the old chip and fitting a new one. I really can't afford this kind of equipment for doing an occasional job, I whiched I could... Do you have the right equipment and spare SCSI chips ...

I already tried an external enclosure: it's not working, same reslt: tried 3x 100% known good drives. The PSU is not the issue as well as both PSU and Analog board are fully recapped as well. PSU is stable, no drops or spikes in voltage as I logged both the +5v and +12v lines while testing...

I have just finished testing all traces from the SCSI chip: not a single broken one xx( I don't know anymore, it's just sad because it's a socketed version of the logic board. Now I recapped another one and while it powers on: it can't find the SCSI hard drive at all: this one looks even...

I have done some additional testing. It doesn't boot from an external hard drive as well with OS 7.5.3 for an SE/30. I get the same errors: doesn't recognise the disk, unable to mount I have checked the 3x Bourns filters: all measure 54 Ohms pin-to-pin in circuit so I guess these are OK. I'm...

I recapped an SE/30 board yesteray but keep getting disk errors for the internal hard drive. I got the board dead, with SimaSimac, so impossibe to test before. Replaced all capacitors. The board posted but couldn't find the internal hard drive. However if I boot with a floppy disk, the hard...

Chances are very thin that a faulty diode would cause problems like yours. Then the diode must make contact to the ground from the Mains, which is very unlikely. Anyway: test the diodes, a cheap DMM can do this without desoldering them from the PCB. Definately replace the C1 capacitor as well.

My Macs are also International 230 volts versions. I have already recapped all of them in the last years ( so logic, analog, PSU ). Finding exact replacements is often not that easy if you want to make it look right as for example a 100uf 200v capacitor from 25 years old is much larger than one...

I did post links from Mouser earlier in this topic where you can still buy the identical film capacitor. I think Digikey offers them as well. Replace them and you're good to go for another 15 years :)

Yes I can confirm that Apple sold an upgrade kit from 128K to 512K which contained only a 512K logic board. I have one of these upgrade boxes, I will post of picture of it when I comes through my hands. These upgrades were not sold directly to end users but were delivered to Apple Dealers.

It's the combination of a circuit braker with integrated safety switch. It will be the safety switch, probably a 30ma one which is very sensitive when there's a difference between the ground and the active that trips the braker. So recap the Analog board including the 3x EMI/RFI capacitors and...

I had exactly the same problem with an SE/30 that persisted even after replacing the Vrams. So I doubt replacing them will solve the issue. It did show up out of the blue on mine several months after fully recapping the logic, analog board including the PSU. Only with a scope you can find the...