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This question isn't actually device specific, but I don't see a forum for general component questions - so here it goes. I need to recap a Toshiba T4600C, and there are quite a few of those plastic-encased electrolytics... the values of most of them are obvious, but one type is not (at least to...

Do the machines operate normally otherwise? Some Pluses do this, I believe it's dependent on the drive installed. It's considered normal operation and nothing to worry about ---- is the drive installed a MFD-51W-03?

Another one! Yes - I've never seen the sockets on NA boards, but I've heard of them being on International boards. Certainly makes troubleshooting / fixing easier.

Booting without the keyboard will display a test pattern. EDIT: Further clarification... later ROM versions would run a diagnostic test if you booted without the keyboard attached, but 255 ROM's don't do this... instead it just runs a cycling test pattern that doesn't really tell you...

Ah right - apologies - I clearly scanned right past key parts of your original post... 😬 I'm on a roll. Other than verifying the floppy cable is good, you're into typical board-level diagnostics now since isn't any easy way to isolate the issue based on these symptoms - it could be I/O...

Strange. There are several different images out there, so maybe try a different source. There's also many other diagnostics tools, some of them with RAM tests: https://mirrors.apple2.org.za/ftp.apple.asimov.net/images/disk_utils/diagnostics/

The MECC diagnostics tool has a decent RAM test (https://macgui.com/downloads/?file_id=9613). It won't tell you exactly which chip may be an issue, but it will at least isolate it to either the main or aux bank. And then you'll know it's indeed a RAM issue (it seems like it to me fwiw). ROM 4X...

Nuts. Jinxed it.

The running joke is over! Now what?

Location Voltage Capacitance Height Diameter Board Lead Spacing C201 16V 2200µF 25mm 12mm 5mm C203 16V 330µF 14mm 8mm 5mm C206 25V 100µF 11mm 5.5mm 5mm C251 (secondary side daughter board) 50V 2.2µF 5.5mm 4mm 5mm C109 (primary side) 400V 47µF 25mm 16mm 7mm

For IIGS: KEGS for modern machines, cross-plaform https://sourceforge.net/projects/kegs/ Bernie ][ The Rescue on older Macs (8.5+) https://macintoshgarden.org/apps/bernie-ii-the-rescue

Nice work, and excellent video! Quick note of clarification: tunnelling only affects ACTIVE matrix display, so only the 170 and 180. The other Powerbooks are unaffected (I just noticed you mention the other PB's in your show notes). Well done sir!

LOL I know a guy named Vern and, yeah, that scans. 🤣

Well, I did a quick wire up and some tests on CRT and LCD and afaict there's no actual difference between the NTSC signal at the video connector vs the composite connector, despite emerging from different pins of the VID hybrid. So, yeah. If someone else has a different experience, I'd love to...

Has anyone made this adapter? https://www.ebay.com/itm/193393714278 Apparently it merely pulls the NTSC composite signal from the video port (as well as the audio signal from the same port)... is that it?? https://devonhubner.org/AppleIIc_Video_Port_Breakout/ Word is that the output quality is...

IEC produces or maintains a stock of many cables and adapters we often need in our hobby (as if we need more). It's a good place to check for DuoDisk cables or Male DIN5 to Female DIN8 adapters... if you don't want to make your own or can't find one: https://iec.net

Jameco often has deprecated / hard-to-find IC's in stock, such as 4164 RAM chips and the CA3146E write amp that frequently fails on Disk ][ drives: https://www.jameco.com

Nice work getting this machine restored! It's always an interesting journey... I honestly think there's nothing to suggest until those caps are replaced and you see whether or not the issue is resolved - and you know you're working on a good baseline. I'm... 66% sure the caps will solve this...

Oh, that would be lovely. I'll have to take apart another machine to get the cable, but that won't be an issue. It might take me a few days to get around to it, but I'll DM you the images and measurements. It's a very simple cable, as you can see.

It appears they have male DB-19 connectors for $2.50/ea!!