Tuesday, December 30, 2008

Getting the feet wet

The long holiday gave important time to look through the damage in great detail. The copper traces have all eroded away there are no connectivity between components. The only way forward is to perform point to point wiring to restore back the lost connectivity. After looking through various catalogues, I settled on 30AWG wire wrapping wire that gives the required stiffness, while being strong enough to withstand handling on the board. Thicker wires are not required here as the wires will be handling small signal levels.

First, all the corroded solder was removed and solder joints were repaired. Next I tried out some wiring and they seem to hold up well. The wires were routed as close to the original trace design as possible. Because the semi-conductors are not on sockets, there is a possibility of component damage if heat was applied too long.

I will be doing more of the wiring over the next few days and put up some pictures.

Tuesday, December 23, 2008

Looking Inside

Today I got the time to look into the 700ZXL to see what caused the problem. I was met with a deck packed with circuitry, all neatly organized and labelled. A quality machine indeed! Some screws were noted to be missing and some connectors were not correctly positioned.

Opening the back panel was easy. Releasing some screws allows the back panel to fan out. Bad corrosion was observed around the battery compartment.

Removing the auto-computing section brought more bad news. The corrosion had affected the bottom board and pieces of metal had falled on the components. The board has been badly damaged by leaking battery chemicals! This board controls all basic deck functions like play, record, rewind, forward and controls the cassette mechanisms.

The auto-computing board had not been spared as well. Leaked battery chemicals had spilled on the board and oxidized the board! Copper tracked had been eaten away and the board had been partially destroyed!

The opposite side of the board, the component side, seems to have been spared damage.

Upon closer inspection, the components seem to be in good condition. Only the printed board tracks seem to be damaged. The other board has not been damaged at all and looks to be in good condition. Over the week, I plan to explore different ways to repair the damaged sections. Looks like this lady is not going to be singing as soon as I expected.

Friday, December 19, 2008

The first meet...

The first glance upon this beauty shows a clean, zen-like design that blends in with today's modern minimalist looks. The left door opens up to reveal more controls. Powering her up only displays the lights. Nothing else seems to work. This deck had supposedly not worked for a long time and needs a complete work.