Dell Pentium Pro Restoration — Part 1c: Test results & PSU in detail
The end of our tests, and the power supply is (mostly) performing at an excellent level! Our main concerns were voltage output regulation which it passed with no problems. I’m confident the supply is safe enough to power the motherboard and all of the peripherals. There are a few tests where we uncovered some issues, […]
Dell Pentium Pro Restoration — Part 1b: Power supply testing
During testing, I’ll be powering the supply through an isolation transformer for safety, and will also use a variac to test the power supply with lower and higher AC voltages. For measurement, I’ll be using a Rigol DS1102E oscilloscope as well as a BK Precision 2709B digital multimeter. This is an entry-level scope with limited […]
Dell Pentium Pro Restoration — Part 1a: The power supply
Before powering up the system or doing anything else, I want to see what condition the power supply is in. The importance of the power supply is obvious: without it functioning properly, the condition of anything else in the system is a moot point. Not only do we need the appropriate voltages, we need them […]
AKAI Midimix
I thought I might start posting repairs that I do for my small business called The Resistance.
Dell Pentium Pro Restoration – The Plan
After getting the system out of the closet, I took photos to document the current condition. Overall, it’s in nice shape given its age. I didn’t see anything structural that was damaged, e.g. no missing or broken plastic. The plastic on the case as well as on the drives has yellowed over time. This is […]
Dell Pentium Pro Restoration – Intro
Introduction By the time I was forming memories as a young child, we always had a computer in the house. My dad was a software and database engineer; he worked in several industries, including in the aerospace field where he wrote software for Pratt & Whitney rocket engines. The first computer I remember was a […]
Brother HL-L2360DW repair
The problem My Brother HL-L2360DW laser printer went into a reboot loop after a power outage. The LCD initializes and displays solid blocks, followed by a blank screen, and the Wifi button LED blinks once, and then the cycle repeats. Holding the “GO” button either during startup or while it’s looping puts the printer into […]
Phono preamp
A friend of mine designed a simple phono preamp for me to use with my newly purchased turntable. Once he was done with the design, I used EAGLE to design PCB layouts for both the power supply and amplifier boards. They were fabricated by OSH Park. The power supply outputs 27V and uses a LM317LZ […]
Fisher CA-272 rechassis
I bought a Fisher CA-272 100w/ch amplifier that had very noisy controls. Specifically, the amplifier had a built-in EQ and the sliders were deteriorated to the point of being unrepairable. Instead of ditching the amp, which sounded relatively good, I decided to transplant it into a new chassis. The cool thing about this amplifier was […]
Compaq Portable PC
The Compaq Portable was one of the world’s first 100% IBM PC compatible computers, and definitely one of the first real “portable” computers. It’s not really portable by today’s standards as it is nearly 30lbs, but in 1983, it was groundbreaking. A co-worker posted one for sale on a company bulletin board as non-working. He […]