mecha
Well-known member
well, I too acquired a Defender recently. machine was super dirty, so my first step 2 weeks ago was to give the PCBs rubbing alcohol baths. I pulled all socketed chips. the ROMs had a lot of corrosion on the chips so I sanded those and reinstalled them accordingly. I used those commercial hand dryers in our bathrooms for drying the boards.
the triacs transistors on both the sound board and main board had either instances where the legs broke entirely, or they were a twisted/tangled mess. I bought replacement 2N4400s at Radio Shack (I researched this from another Defender thread on here) and ran across some 2N4403s along the way. I MAY have reinstalled the 4403s in wrong spots, I know all the 3 video ones are correct, I've seen on threads here where people are talking about parts locations on the boards, and mine have no identifications for what's what at all, unless I'm supposed to read the manual.
I get no startup sound, however you can hear the amplifier kick on, and all I have are 4 solid lights on the ROM board (they do not flash at all). there's a chance the color balance is jacked up on the monitor (a Sampo, if that helps) I get what appears to be a red screen
point of interest: I've noticed there's some oxidation on a few chips near where the battery holder was. I removed the old battery holder and picked up a CR2032 socket but haven't done that mod yet. I really just wanted to see if the game would even turn on.
I double checked all my wiring off this: http://www.cityofberwyn.com/schematics/williams/DEFlay.tiff
I had 5.20V at the switching power supply (mine's moded, the original PS board is missing).
thoughts anyone? did I fuck up when I cleansed the boards or is that a common problem if there's battery leakage? I never observed the green oxidation around the pins before cleaning.
the triacs transistors on both the sound board and main board had either instances where the legs broke entirely, or they were a twisted/tangled mess. I bought replacement 2N4400s at Radio Shack (I researched this from another Defender thread on here) and ran across some 2N4403s along the way. I MAY have reinstalled the 4403s in wrong spots, I know all the 3 video ones are correct, I've seen on threads here where people are talking about parts locations on the boards, and mine have no identifications for what's what at all, unless I'm supposed to read the manual.
I get no startup sound, however you can hear the amplifier kick on, and all I have are 4 solid lights on the ROM board (they do not flash at all). there's a chance the color balance is jacked up on the monitor (a Sampo, if that helps) I get what appears to be a red screen
point of interest: I've noticed there's some oxidation on a few chips near where the battery holder was. I removed the old battery holder and picked up a CR2032 socket but haven't done that mod yet. I really just wanted to see if the game would even turn on.
I double checked all my wiring off this: http://www.cityofberwyn.com/schematics/williams/DEFlay.tiff
I had 5.20V at the switching power supply (mine's moded, the original PS board is missing).
thoughts anyone? did I fuck up when I cleansed the boards or is that a common problem if there's battery leakage? I never observed the green oxidation around the pins before cleaning.
