Repairing the king! Bringing a Sony D-Z555 back to life and giving it a new rechargeable battery

Like many others that grew up in the 80s/90s, you probably have fond memories of going to school listening to your Sony Walkman or later on their Discman. Among the many models of portables that Sony made over the years, a few top of the line models remain in the minds of collectors and audiophiles alike as the best sounding portables ever made. Walkmans like the WM-DD9, WM-DD100, WM-DC2 with the king in terms of sound being the (semi-portable) WM-DC6 - which reigns as one of the best portable cassette players ever made.

On the realm of digital music, Sony had their Discman series. This line has a few players that commonly make the top of the list of the best players ever made are the D-Z555 (also called D555), D10/D100, D35, D303 and D350. More often than not, the throne of the best Discman ever made goes to the D-Z555 for a combination of features, looks and sound quality.

Note that the best portable disc players were made in the early 90s and below, when it was considered a luxury item made for audiophiles. When the Discman became more main stream, some features were added such as ESP (Electronic Shock Protection) or later MP3 discs playback, but with these new "features" it came price cuts and the end of their high-end units.  

The Sony D-Z555 was released in 1989 and it features not one but two (!) backlit LCDs displays, one of the displays spotting a spectrum analyzer (how cool is that for a portable!?). Inside the unit, you will find two audiophile-grade PCM66P DACs and for the very first time on a portable and consumer device: 8 times oversampling and a DSP chip. The player also spot a digital optical output (which was a very new technology in 1990, especially on a portable unit!), a remote port (for an optional IR remote) and line out. 

The Sony D-Z555 (or D-555) and it's 2 backlit LCD displays in action
PS: testing it with a great game soundtrack from the time the D-Z555 was released (1990)!

Restoring a Macintosh Color Classic

The Macintosh Color Classic is a very collectable Classic Macintosh. It is relatively rare as it was only manufactured for a little over 2 years and is the only classic Macintosh that comes with a Sony 

Color 10" CRT monitor as opposed to the standard 9" B&W CRT display present in all other Compact Macs.

Macintosh Color Classic running System 7.5.5

Recapping a Macintosh SE/30 and a IIsi logic boards and the IIsi power supply

Many vintage (15+ years) electronic boards (PCBs) are at a higher risk of having its non-solid electrolytic capacitors leaking by now. Such leaking occurs regardless of whether the component is actually being used/energized (although storage conditions may further contribute to the component degradation). The leakage happens due to natural aging of the component sealing and/or internal corrosion within the capacitor. The consequence of such leakages can be catastrophic not only for the capacitor itself, but for the electronic board as a whole. Here is why...

The most commonly used capacitor (aka caps) in computer logic boards and power supplies are the non-solid electrolytic capacitors, which use a liquid or gel as electrolyte. The problem is that the electrolyte liquid/gel used in these caps are conductive and corrosive and both these characteristics do not go well if spilled over your PCB. Therefore, when these capacitors leak, they can cause:

1) The PCB to malfunction by creating electric contact (short circuits) between components that were intended to be connected. Depending on the short circuits created by the conductive liquid, it could completely burn components and even create holes in the PCB, potentially damaging the board beyond repair. 

2) In addition to shortening components, the corrosive nature of the electrolyte will (with time) corrode the copper traces on the PCB as well as the components terminals to a certain extent. The electrolyte will also cover the solder joints creating a crusty layer that shields the solder joint from heat, requiring you to add more heat to be able to remove components (by desoldering).

Macintosh IIsi Power Supply with leaky capacitors