Still trying to repair that Excelerator Plus

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Gyro Gearloose
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Still trying to repair that Excelerator Plus

Post by Gyro Gearloose »

Rest assured I haven't been working on it for two months... I simply put it aside while waiting for parts.

But as luck would have it, the 6522s I ordered didn't arrive, instead I got a bag of 6502s...

I notified the seller of this error, and I'll just keep waiting... :|


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rmzalbar
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Re: Still trying to repair that Excelerator Plus

Post by rmzalbar »

Can you post a photo of the mechanism from the top? Mainly the spindle clamp/head lifter area. I think there are at least two types of Excelerator Plus.
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Re: Still trying to repair that Excelerator Plus

Post by Gyro Gearloose »

There are at least two board versions, of that I am sure. However since I am no longer physically at work and all my junk orders get delivered to work, I have no new chips in any case.
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Re: Still trying to repair that Excelerator Plus

Post by Gyro Gearloose »

Apparently someone will collect my eBay junk at work and send them but it's really not important so ...
more waiting. In the meantime I desoldered the 40 pin DIPs and now I have to repair the 5 lifted traces I created. What a junky PCB...
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Re: Still trying to repair that Excelerator Plus

Post by rmzalbar »

I did work on an Odyssey 2 tonight that also has easy-to-lift pads. My fancy vacuum desoldering gun was sucking them right off, so I set it aside and switched to my tried-and-true method of:

1. Stand the board vertically
2. Put flux gel along chip side joints
3. Put spring-loaded solder sucker onto the bottom side joint with one hand
4. With other hand, on the chip side of board, put soldering iron onto the flux-gelled joint.
5. Give it several seconds of melt, then fire solder sucker.

Solder gets yanked out from the (relatively) cold side, so less stress and no lifted pads. Plus the spring-loaded sucker tip gets a great seal since the iron is out of the way on the other side of the board. The chip will probably be just a little bit stuck after that, where the pins rest on the board surface on the top side. They will probably let go without any damage; however, not wanting to risk prying cold and cracking any weak pads, I then run hot air at 250°C along the chip side legs, just enough really to get the solder in a weakened plastic state, while prying gently to get the chip free in a few seconds, first one row then the other, without stressing any pads.
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Re: Still trying to repair that Excelerator Plus

Post by rmzalbar »

I just put Jiffydos in my FSD-2 tonight. It looked like it was going to be easy, right? I mean you just take off the bottom plate and the rom is right there in a socket! It was a deception.

The ROM presses right up against up against the bottom plate, so there isn't clearance for the JiffyDOS adapter. Yes, you could just press an EPROM in and be done, but I had the physical version that comes on a thin wafer with a switch, and that stands just a little taller.

So to do a clean job I had to remove the socket and solder it straight in. There was little space for a switch and clearance to route wiring , but I finally found room to mount a tiny slider switch just above the power switch.

I didn't have any trouble soldering on it, but I do note the PCB is thin and the traces and pads are small. Not unlike soldering on an Amiga, actually. I prefer small pads anyhow because they take the heat quickly.

Mechanically however it's a bit of a pain in the neck. Crappy connectors, fiber washers in awkward locations, shims that dislodge and need gluing, bodge wiring everywhere that you have to be careful of.
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Re: Still trying to repair that Excelerator Plus

Post by Gyro Gearloose »

Yeah not my favorite drive. I've put this little clunker on the back burner, it's a bag of never-ending problems.
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