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The PowerBook 5300c has three circuit boards with electrolytic capacitors. The locations and specs may vary in other models such as the 5300ce and 5300cs. Location(s) Capacitance Voltage Pads (edge to edge) SMD Size Recommendation Notes INVERTER BOARD C3 10uF 50V 9.5mm C (6mm L)...

Sorry just realized I gave you that same advice earlier. Normal operation is that the fan will run if the MLB is not installed. Did you recap and clean the logic board too? If you just get a brief click when it's installed you might have an issue with the EGRET chip which manages ADB. You might...

One more update to this project. I spliced the audio cables, which got the speakers working, but they were very quiet. I read somewhere else online that the amplifier IC in powered PC speakers and wear out over time and lead to this symptom. I thought that sounded weird, but worth a shot. Before...

It looks like you only ordered 1x SN74F253 but there are 4 on the board.

I was off by one silkscreen looking at your photo. UA8, UB8, UC8,UD8 are SN74F253 UE8 is SN74LS166 UF8, UG8 are SN74LS393

Also, this trace is looking questionable. Refer to @Branchus 's videos for how to scrape it down, check and repair it if needed. Lastly, the ROMinator tends to not make good contact with the pins on the SE/30. I wouldn't rely on testing with it unless you have an ATX extension to test with the...

I think the fact that you're seeing a garbled flashing ? is another indicator that your issue may just be with the muxes. Yes, remove with hot air, clean underneath with IPA, scrub the pads with solder wick/fresh solder and reinstall (using lots of flux). If that doesn't help you can find...

Swapping it into the SE is not going to help. A few things to try: Try one bank of RAM at a time in bank A. Clean the contacts on the ROM. But most likely this is due to a broken trace to/from the ROM or RAM or bad / dirty video mux. UE8 (74F253) is a common failure point due to its proximity to...

I've corrected some stuff on the top enclosure and created the bottom enclosure model. I'll try to make a test print in the next day or so.

Top enclosure draft done. Will hopefully get the bottom done later today and will attempt a print shortly after.

Well, conveniently, someone recently did all of the hard work. Yay! I'll work on an enclosure.

I recently got a TechStep working and of course am interested in getting the full set of ROMs. They're quite hard to find, so it might make more sense to just recreate them. The enclosure geometry is a bit complicated but should be fine to print in resin. The PCB is quite simple too. It consists...

My ROM B has generic SCSI tests on it.

It powers up with a power adapter but still not with the battery. It’s probably something simple on that DC-in board but haven’t been able to figure it out yet. Anyway, this is good enough for now :)

I replaced the ribbon cable with one that's a touch longer. The TechStep still does not display anything on screen and still doesn't show voltage at the voltage regulator. Back to trying to following the path from the battery more closely.

Maybe focus on the feedback circuit of the analog board. Consider changing the optocoupler and/or the diodes near it.

I came across a manual for the Macintosh Portrait Display, and it conveniently included a pinout of its quite hard to find video cable. Here it is in case you need to build your own.

The power jack is center negative. I expected something to be blown from someone connecting a more typical center positive adapter. I don’t think there’s any protection against that. hopefully all this needs is to have these wires reconnected. @splorp Have you opened yours up yet?

While double-checking the connections from the battery and barrel, I noticed the ribbon cable was a bit too wiggly. After pulling lightly I found the battery positive connection was broken. Hopefully reattaching that will fix the issue.

After years of searching, I've finally scored a TechStep. Unfortunately it shows no power with a good 9V battery. I haven't ordered a power supply yet, but suspect it'll produce the same result. Nothing is scorched and so far all of the joints I've checked look okay. However, 9V is not making...