Recent content by jdmcs

I'm thinking of going to the Silverball Pinball Museum in Asbury Park, NJ the evening before the swap meet, for anyone else that would like to join me. Admission is $18 for one hour or $20 for the rest of the day. I'll probably be there sometime after 7PM. (Note that the parking near the museum...

If the system has VLB slots that you would like to use, then you want to go the DX4 100MHz route. The reason Intel abandoned the DX 50MHz (so I've been told) is that other chips weren't always reliable at a 50MHz bus speed, though shortages of the DX 50MHz may also have contributed to poor...

My PC Chips M326 motherboard is now dead. I believe the root cause was plugging the AMD 386 40MHz processor I had in incorrectly one too many times, as it is mounted on a PQFP to PGA adapter board that requires careful attention to the pin 1 indicators. I one too many time fell for aligning PQFP...

If you remove the leaking capacitors and clean the board, you're probably OK to power up the board. As others have mentioned, you won't have sound, and the system will eventually become unstable. Worst case is the board won't have enough capacitance to keep the voltage rails within tolerance and...

The most recent System Source Swap Meet on April 27th had the largest seller turnout of the three I've attended. It was worth my trip up from Central Virginia, but I should disclaim that I drove halfway and then rode up with RetroTech Chris the rest of the way. If you want to get an idea of...

Note that the Swap Meet has been moved to Sunday the 27th due to the forecast for heavy rain on the 26th. The Repair Workshop remains both days, but will be all-day on the 26th and start after the conclusion of the Swap Meet on the 27th.

I'm going to try to make it to the VCF Swap Meet in NJ this time around. (I am also 99.9% sure I'll be at the System Source Swap Meet next weekend.)

I've seen these power supply upgrades in photos, but not in person - they were part of some upgrades because the original power supplies had little margin for upgrades. I suspect there was an accelerator card in this Mac Plus that has been removed, as normally you wouldn't be able to install an...

Have you re-capped the logic board? If so, you might want to inspect for shorts around the replaced capacitors, especially if you used tantalum capacitors with a shorter pad spacing than the original electrolytic capacitors. You might also check out this video from Adrian's Digital Basement...

Have you recapped the Delta power supply? I have had two, and they both had leaking capacitors. Note: They're not fun to re-cap. Measuring the voltages of these power supplies is a pain, as they plug directly into the logic board. I've done it before by putting the power supply on it's side so...

I am having trouble finding technical documentation on the IBM Portable Personal Computer 5155 (which I'm going to simply refer to as the 5155 from here on out) in regards to the voltages that the analog board can output to the CRT. And from seeing Adrian Black try to repair a terminal recently...

I realize the answer could be that I bought a PC Cheaps... I mean, PC Chips motherboard on eBay, and a 50% POST-on-power-up ratio should be considered good. However, this issue could extend to other boards, and maybe there is another issue that is the cause. I have a PC Chips M326 V2.7...

I didn't think the pins on the keyboard connector would fit in a machined socket, but I just found one that I had on hand, and the pins appear to fit. I'll just have to get some in DIP-16 size next time I order from Mouser. I'm not sure if a ZIF socket would fit. If I can find dimensions of a...

On the Apple II series, Apple used a different DIP socket for the keyboard, game pad, and for the Apple II and II+, the memory chip at E3. It was a socket designed to accept an IDC ribbon cable with a DIP plug. I need three of these sockets, and I’m having trouble finding them partially because...

It's close - it has two tabs and doesn't appear to be retained by a screw (probably just the motherboard keeping it in place). Here's a crop of the photo of the one I bought: I'll get better photos once I receive the case.