VOGONS


First post, by Solo761

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Hi all, recently I got Abit AB-PW4 motherboard. Unfortunately it had pesky Varta barrel battery that leaked so I'm cleaning that up.

On it I have one transistor and crystal oscillator that look to be a bit dinged up, they might still work, but I'd rather replace them then worry about it. Problem is that I can't read their values. Crystal oscillator is completely clean and transistor still has something legible but not entirely readable.

Does someone have this motherboard and can read their values or someone perchance knows their values? For transistor I'm unsure if it's 2N3905 or 2N3906, to make matters worse they're same type but different spec. I could put 2N3906 in there but if it was originally 2N3905... 2N3906 has double amplification of 2N3905 so that might not end well 😬.

The attachment AB-PW4.jpg is no longer available

There is third transistor below crystal oscillator, but that one is readable, 2N3904, so that's OK.

Reply 1 of 2, by Babasha

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Xtal looks like usual CMOS-clock xtal 32768 Hz.

Need help? Begin with photo and model of your hardware 😉

Reply 2 of 2, by Solo761

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Thanks, that seems the safest bet.

Silkscreen under RTC says DS1287/DS146818A, although it had M5818 installed. DS1287 ones don't seem to require external oscilator, but M5818 it had does. Although I can't follow the trace at the moment from OSC pins on RTC to oscillator. We'll see when I finish reaparing traces.