A2000 mouse trouble - Am I Fubar?

[MrWho]

Hello there. First of all, since this is my first post, I'd like to present myself. I'm from Portugal, I'm 27 and I like to collect everything computer-related that reminds me of my old times. I keep most of the parts that went through my PC and I'm actually still looking for the exact same model of Spectrum I had several years ago!

But, getting on-topic, I'm about to put my hands on an A500 (the same model I used to play on a friend's house when the Spectrum I had was starting to show its age). So, I dug out an A2000 a friend offered me a couple of years ago and I was experimenting with a serial cable in order to transfer some ADF files back to disk. Trouble is, after that experiment of mine, the mouse (using the other port) stopped working. I mean, not totally: the buttons still respond, since when I click them, the top window changes colour, but when I move it, the cursor never leaves the top left corner of the screen.

Did I screw up something for good? I don't know anything about the Amiga hardware, so any help would be appreciated!

Cheers!

[JimS]

Takssista:

It sounds like you may have blown the fuse inside the 2000. There is +5v on the mouseport for the electronics in the mouse ans well as other gizmos that might plug in there. The buttons don't need it since they are just switches.  You can check between pins 7 and 8 for 5v. Those are the middle 2 pins on the bottom row. If there's no 5v there, it's probably the fuse. You'll have to replace it on the motherboard. It should be labeled F1 and near the mouse ports. It will look like a resistor without the color bands.

From what you said, "the other port" it sounds like you connected a 9-pin serial cable to the second mouse port. The serial port on a 2000 is a 25 pin port in the back.

Good luck...  

Jim

[MrWho]

I see. I'm no electronics guy. Is it easy to exchange (no soldering iron necessary)?

Thanks for the feedback!

Edit: I just read here that said fuse just appeared in the later models of the A2000 (rev. 6 onward, if I'm not mistaken). I need to check if my model aplies. Anyway, if it doesn't have the fuse, I'm wondering if it is worth fixing (depending on how easy it is to find the blown chip for replacement)... Oh well...  :-(

[Castellen]

Sounds like you might have taken out U202, a common 74LS157 quad flip flop.
Should be easy and cheap enough to find another and replace it.
Any variant like a 74HC157 should work fine as well.

Schematics on the A2000 here if you need them:
http://amiga.serveftp.net

Can't remember if it's socketed or not.  Hopefully not, those sockets are crap.

And remember not to plug your RS232 cable into the joystick port :-)

[JimS]

If it is the fuse, it is a soldering job to replace it. To do it right, you have to take out the motherboard. I suppose you could just clip the leads and solder to the ends of the old fuse. As for the revision level, you're right, the older motherboards don't have a fuse there. I have seen it vaporize traces on those boards. You would have to use some wire to repair the connection.
It could be that chip mentioned also... that will be a soldering job also, it's not socketed. Whether it's worth it is up to you... I'd fix it, but I used to do that stuff. :-)

[Tenacious]

If you decide not to repair the A2000, don't toss it into a dumpster.  There is a finite number of these left in the world and a lot of people who log in here that would love to have it, even with a minor hardware flaw.  The A2000 is one of the most collectable Amigas.

[MrWho]

Castellen: I think I'll leave the repair to sometime later, since I'm in the process of moving to a new home, and the last thing I need is a dismantled computer to worry about. Anyway, I'll try to find out how "common" is that chip. Thanks for the tip.

Jims: If you put on some boxing gloves and try to pull a particular hair from your head then that's how handy I am at doing soldering jobs.  :-D Anyway, I'll try to convice some friend of mine to do the job for me. I just hope there's no major damage as you say it can be.

Tenacious: If I decide not to repair it, then I'll be very much willing to give it away to anyone who's willing to pay for the postage or to pick it up at my place. Even if nobody does, it's very likely that I keep it around, unless I really run out of space.

[Jope]

The A2000 is one of the most collectable Amigas.

Oh? What makes it so?

[EnyGmaTiK]

Takssista wrote:

Tenacious: If I decide not to repair it, then I'll be very much willing to give it away to anyone who's willing to pay for the postage or to pick it up at my place. Even if nobody does, it's very likely that I keep it around, unless I really run out of space.

Hum... Shipping that sweet machine to moi doesn't strike me as being that expensive  :-D

Bem-vindo (é assim que se escreve :lol: ) ao forum.  :-)

[MrWho]

EnyGmaTiK: Obrigado pelas boas vindas.  :-) And don't worry. If I decide it's not worth it, I'll post it here firsthand.

[weirdami]

Oh? What makes it so?

Old people on a nostalgia bender and money to burn on ebay.  :lol:

[JimS]

Takssista wrote:
Jims: If you put on some boxing gloves and try to pull a particular hair from your head then that's how handy I am at doing soldering jobs.  :-D Anyway, I'll try to convice some friend of mine to do the job for me. I just hope there's no major damage as you say it can be.

Well, as Dirty Harry says, "A man's got to know his limitations." :-)
Seriously though, none of those soldering jobs would be difficult for your electronically skilled friends. The 2000 isn't like the 1200 - full of surface mount chips impossible to deal with without special tools.
Good Luck.