Death Walker
Member
Hi everyone, I have a LCII which I bought on Ebay. Suffice to say the seller used "boots up" instead of "drive makes sounds" and "unit powers up" instead of "unit started once and died".
I have recapped the PSU and it works again. I have tested it with a known-good LCIII and there are no issues.
The LCII goes to a white/grey screen and there are no speaker chimes.
If the unit is left on for more than 10 minutes, the speaker begun to scream a little.
I have recapped the main board and now the speaker makes no screams or chimes.
There is no battery damage.
I observed no capacitor leakage or damage to the PCB.
After reading about previous fix attempts, I have traced the tracks/via for the reset signals from U10 to the 68030 and are electrically intact.
I have powered up the main board and the RST signal from #15U10 remains low for about 1 second, then rises to 5V without any dropouts.
The fan spins up whenever the LCII is turned on.
I have tried starting the LCII with and without memory simms, with/without HDD/FDD, even with/without VRAM.
The LCII has a new 3.6V PRAM battery, have tried with/without it installed too.
I noticed that after running for about 10 mins, the 68030 chip is quite warm to the touch. If it is doing something, I don't know what it is. No other chips are warm at all.
I am using a VGA adaptor to an LCD monitor that I have tested on a known-good LCIII (640x480).
The LCD monitor detects a 640x480 video signal when the LCII turns on and displays a grey/white screen with no flicker or lines.
There is a 2x3 header pin block (J17) that has no connectors in it. I assume this is left empty so the GLU A20/A21 pins do not connect to the UB2 ROM pins 31/1 ? I have seen working mainboard photos where there are no header pins connected.
I am assuming that because there is no chime at all, the ROM firmware isn't starting.
I have removed the ROMs, and cleaned the sockets and ICs carefully and returned them to their original positions. I have checked their part numbers against the BOMARC schematics and they have been seated properly.
Currently I'm not sure how to proceed. If I trust the seller and the unit was working before it went into storage, then I think I've followed all the simple-fixes that should have resurrected this beastie.
I have no way to currently check ROM and memory ICs for faults, the known-good LCIII has different ROM/RAM components.
Does anyone have any suggestions ?
Have I missed anything obvious?
Any suggestions would be appreciated. Thank-you for reading my plea for help.
I have recapped the PSU and it works again. I have tested it with a known-good LCIII and there are no issues.
The LCII goes to a white/grey screen and there are no speaker chimes.
If the unit is left on for more than 10 minutes, the speaker begun to scream a little.
I have recapped the main board and now the speaker makes no screams or chimes.
There is no battery damage.
I observed no capacitor leakage or damage to the PCB.
After reading about previous fix attempts, I have traced the tracks/via for the reset signals from U10 to the 68030 and are electrically intact.
I have powered up the main board and the RST signal from #15U10 remains low for about 1 second, then rises to 5V without any dropouts.
The fan spins up whenever the LCII is turned on.
I have tried starting the LCII with and without memory simms, with/without HDD/FDD, even with/without VRAM.
The LCII has a new 3.6V PRAM battery, have tried with/without it installed too.
I noticed that after running for about 10 mins, the 68030 chip is quite warm to the touch. If it is doing something, I don't know what it is. No other chips are warm at all.
I am using a VGA adaptor to an LCD monitor that I have tested on a known-good LCIII (640x480).
The LCD monitor detects a 640x480 video signal when the LCII turns on and displays a grey/white screen with no flicker or lines.
There is a 2x3 header pin block (J17) that has no connectors in it. I assume this is left empty so the GLU A20/A21 pins do not connect to the UB2 ROM pins 31/1 ? I have seen working mainboard photos where there are no header pins connected.
I am assuming that because there is no chime at all, the ROM firmware isn't starting.
I have removed the ROMs, and cleaned the sockets and ICs carefully and returned them to their original positions. I have checked their part numbers against the BOMARC schematics and they have been seated properly.
Currently I'm not sure how to proceed. If I trust the seller and the unit was working before it went into storage, then I think I've followed all the simple-fixes that should have resurrected this beastie.
I have no way to currently check ROM and memory ICs for faults, the known-good LCIII has different ROM/RAM components.
Does anyone have any suggestions ?
Have I missed anything obvious?
Any suggestions would be appreciated. Thank-you for reading my plea for help.