My Macintosh SE won't turn on.

Hi,

First of all, remember that opening a compact Macintosh computer can be very dangerous because of the high-voltage circuits inside. Always disconnect the computer from the mains (but please note that high-voltage charges may remain for a long time even in a disconnected computer). Do not attempt to carry out any work unless you know exactly what you are doing. If in any doubt, leave troubleshooting and repairs to an expert. Be careful!

Things to try could be removing/reseating memory modules and disconnecting/connecting cable connectors. The 3.6 V logic board battery may be bad. One can inspect the boards (through the use of a magnifying glass) for possibly cracked solder joints or damaged components (such as leaking electrolytic capacitors).

Jan

Addendum

You mentioned that there were no lights and fan sound. I assume no other sounds either. This could possibly indicate a power supply problem (power switch or electronic component failure). If so, the power supply box must be replaced.

Addendum II

A bad battery can cause various effects, including a no-video condition on certain Macintosh models. A leaking battery can damage a circuit board. However, it seems unlikely that a logic board battery problem would lead to an SE not reacting at all (no sounds or lights).

BTW, some SE logic boards are not equipped with a battery holder. Instead, they have batteries with solder leads (3 V?).

Generally speaking, it is not safe to solder on a battery (explosion risk). If a battery has to be soldered, use a model intended for this (with appropriate tabs/leads). Observe warnings and instructions from the battery manufacturer.

Has it been determined that the battery in your SE is soldered to the logic board? In many cases the battery is placed in a cage instead, which simplifies replacement. Verify the battery type and voltage before any exchange.

Jan