moothefish
Member
For many many years I have been trying to get a nice-ish working LC575 that hasn't had its logic board stolen, and so far have either missed out, been priced insanely high, been missing their boards, or been not working. I have managed to acquire two different complete machines over time and both have suffered from leaky batteries. At this point I would really like to get one of these boards going as I don't really want to buy a third machine only to have the same issues. Hoping for any advice on how to proceed with these and if anyone has a schematic for these boards, I would be very interested.
The first board i'm pretty much writing off at this point, it will actually respond to the power key on the keyboard and trigger the power supply in the computer itself etc, but no display or chime, only signs of life are the keyboard lights coming on for a second when the power key is pressed. I cleaned this board up and started repairing some damaged traces, however the corrosion seems to have wicked its way through the different layers of the board, to the degree that there seems to be corrosion in the CPU socket etc.
The second board I recently acquired thinking it had no corrosion, turns out the battery was leaking out the OTHER side near the edge connector where I couldn't see it...typical. Fortunately the damage is much more localised, and this board actually chimes when powered on, but gives no display and gives the chimes of death straight after the normal power on chime. One of the onboard RAM chips was badly corroded, my original plan was to replace it with one from the first board, however once I removed the damaged chip I found half the pads to have disintegrated along with a few traces.
I tried bypassing the missing chip in the hopes that the board might be able to power on without one of the onboard RAM chips, but this made no difference. There are also two SMD capacitors next to the edge connector that have corroded off the board into oblivion, the traces for which are so tiny i'm having a very hard time figuring out where they go, and I don't feel like desoldering the entire edge connector (the traces run underneath it, possibly to it or to a sneaky via underneath).
Ultimately, I would love to have a circuit diagram for this board so I can try running jumper wires directly to the next components in line rather than trying to solder to tiny and likely damaged traces. Would also like to know if it is possible to run the board without one or any of the soldered-in system memory ICs, or if that's just a really dumb idea. Quite amateur at this whole thing as you can probably tell...Any advice is much appreciated
The first board i'm pretty much writing off at this point, it will actually respond to the power key on the keyboard and trigger the power supply in the computer itself etc, but no display or chime, only signs of life are the keyboard lights coming on for a second when the power key is pressed. I cleaned this board up and started repairing some damaged traces, however the corrosion seems to have wicked its way through the different layers of the board, to the degree that there seems to be corrosion in the CPU socket etc.
The second board I recently acquired thinking it had no corrosion, turns out the battery was leaking out the OTHER side near the edge connector where I couldn't see it...typical. Fortunately the damage is much more localised, and this board actually chimes when powered on, but gives no display and gives the chimes of death straight after the normal power on chime. One of the onboard RAM chips was badly corroded, my original plan was to replace it with one from the first board, however once I removed the damaged chip I found half the pads to have disintegrated along with a few traces.
I tried bypassing the missing chip in the hopes that the board might be able to power on without one of the onboard RAM chips, but this made no difference. There are also two SMD capacitors next to the edge connector that have corroded off the board into oblivion, the traces for which are so tiny i'm having a very hard time figuring out where they go, and I don't feel like desoldering the entire edge connector (the traces run underneath it, possibly to it or to a sneaky via underneath).
Ultimately, I would love to have a circuit diagram for this board so I can try running jumper wires directly to the next components in line rather than trying to solder to tiny and likely damaged traces. Would also like to know if it is possible to run the board without one or any of the soldered-in system memory ICs, or if that's just a really dumb idea. Quite amateur at this whole thing as you can probably tell...Any advice is much appreciated
