Sharp X68000 Pro II: Magic Smoke, Transistor & R-Type

New arrivals from Japan. Got myself a broken Sharp X68000 Pro, in hopes I can fix it. Also got some software for it and a couple of Roland MIDI modules. Still missing some stuff I bought for the X68K with a different proxy service. #RETROGAMING #X68000 #IREM #rtype #Roland

Confirmed that it is as described, power LED comes on when you plug it in but when you press the power button, nothing happens.

I guess this might be why it doesn't power on. 😅

I messed up. Didn't have all needed cap values, sourced some new crap ones locally for a quick test. Had to reuse 3 original ones, fortunately the only ones that tested good. Alas, I made a mistake I had never made until now. Installed a cap in reverse orientation. Magic smoke...

(1/8) Here's a story of perseverance for you. A thread 🧵on repairing an X68000 Pro. You can go through the stages of despair with me by reading below. 👇 We start with it not doing anything when the power button is pressed. #RETROGAMING #X68000 #repair #restoration

(2/8) Opening up the PSU reveals it looks like the caps vomited all over the PCB.

(3/8) Gave it an ultrasonic bath to clean up the gunk. Installed new caps except for the only 3 ones that were reading fine. Installed the filter on in reverse... 🤦 Naturally, it blew up.

(4/8) Replaced it and then measured some voltages around the PSU, touched one of the pins on a photo coupler with a probe and saw a spark. So... I shorted something inadvertently... 🤦🤦

(5/8) Replaced the remaining old caps with new ones and replaced the photocoupler with a new one. Still nothing... 😢 Next I replaced some transistors, some zener diodes and another photocoupler to no avail but then...

(6/8) ... Then I found out that this transistor at Q51 wasn't testing OK with a multimeter. Took it out of circuit and it had a short between the emitter and base pins. I replaced it with a new one and..

(7/8) We have a booting X68000! 😁🎉🚀 But... Does it run games?

(8/8) Yes, yes it does. 😍 Here's some R-Type. Thank you to everyone who offered to help when I first posted, I didn't end up contacting anybody but I came close to. In the end I made it but if I hadn't, I would have reached out. @leo__oliveira @Parr_J #RETROGAMING #IREM #rtype

Assembled a DIY BlueSCSI v2 kit from @OneGeekArmy, to use on my #X68000. Waiting on my keyboard and master disk to arrive. Log file says everything is working as intended. It was easy to assemble but I'd recommend not getting the shell, it's very thin and brittle. #RETROGAMING

Just trying out the new bits and bobs that arrived today for the #X68000. Obviously, posting some #Castlevania pics is mandatory.

X68000 partial recap hoping to get video output again. Previously solved the various PSU issues and it was working fine, until one day... no video but I can still hear the games. Sadly, this didn't fix it. 😔 #RETROGAMING #X68000 #repair #restoration

@leo__oliveira or @A3rgan if you guys have any idea here, I'm all ears. 🙏 I don't know if this is a common issue with these. Maybe I plugged in the cable with it powered on or something, I remember as a kid VGA cables tended to spark when you did that.

Regarding this, I suspected it was an issue with the sync signals. Using my newly acquired scope I see readings for RGB and HV but H and V sync voltages seem very low. TTL level sync would present higher voltages. Would the 74ALS05 be the culprit here? @leonkiriliuk #X68000

@leo__oliveira Could you dispense some advice here please?

Finally finishing the recap on my X68000 Pro II. I still hadn't recapped this board and the FD drives. Took the time to clean and lubricate the sliding parts of the drives. Now I no longer need to worry about these sitting there and rotting away. #RETROGAMING #X68000