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TRS-80 Model 3 - Repair

Oh, forgot to say. Let me know if you need any boot disks. Although if you get the HxC and splice it into the 34 way Shugart cable, you can stick an image on it and boot, then transfer the OS to one of the floppies. I got loads, just ask... :)
 
Well as I found the Cumana FDD interface sitting in my PC, I searched for a Cumana drive, I took a punt on a CUMANA CS200 drive to see if it works, it seems to be a 40T double sided 200K drive (so I guess same as Tandys 178K when formatted) hopefully if I change the 34 Way IDC connector on the end it may work, any thoughts ?

I got it for £29 as it does not power on, Im hoping PSU fault and the drive is ok :)

cumana.jpg
 
Will probably need a long cable to run from the top of the FDC, down and out the bottom of the case and then to the disk drive. The connection on the bottom of the FDC is for drives 2 and 3... 0 and 1 need to be connected to the top connector.

Just giving you a heads-up.
 
184 is the capacity of a single sided. 360 for double sided.

Every drive I've picked up this month has been slow or fast by up to 30RPM so keep that in mind when you get drive not ready errors or things aren't working right.
 
Today I spent a good part of the afternoon fixing the keyboard, I had about 5 keys that did not work to varying degrees, the E, A and S pretty much did not work at all, the others worked now and then, the other thing was that a lot of keys repeated so you got 2 or 3 characters for the price of one press.

I started by desoldering all the keys due to the amount of solder I decided to use solder wick rather than keep emptying the desolder station.

keyboard2.jpg


With all the keys unsoldered the top plate and all the keys came away easily:

keyboard3.jpg


They simply push out the metal plate:

keyboard4.jpg


Once out I pulled the key caps off and split the key switches, I found a craft knife the best tool for this:

keyboard6.jpg


You can easily see the issue with the dirty contacts next to one that I cleaned:

keyboard7.jpg


To clean them I made a tool from a screwdriver and some scotch brite, worked a treat:

keyboard8.jpg


I then washed all the keycaps with hot soapy water and a sponge:

keyboard9.jpg


And all back together looking nice and fresh and better still all keys work perfectly with no bounce or repeated characters, a very tedious job but well worth doing :

keyboard10.jpg


Hope this is of some use to someone :)
 

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I am a software engineer who knows nothing about hardware.
I have fired up my Model 3 every year or two to make sure it still works.
Now that my grandkids are old enough to appreciate it, I brought it out, showed them some simple programs they could enter themselves, and played a couple of games. I was so excited to share this with the littles, and they were loving it.

And then it exploded. Pop, flash, smoke.

Where could I ship it for diagnosis and repairs? You guys seem quite knowledgeable.

Thanks so much if you can help!
 
SomaCowJ said:
I am a software engineer who knows nothing about hardware.
I have fired up my Model 3 every year or two to make sure it still works.
Now that my grandkids are old enough to appreciate it, I brought it out, showed them some simple programs they could enter themselves, and played a couple of games. I was so excited to share this with the littles, and they were loving it.

And then it exploded. Pop, flash, smoke.

Where could I ship it for diagnosis and repairs? You guys seem quite knowledgeable.

Thanks so much if you can help!
Click to expand...

This really is one of the easiest hardware jobs to fix on the Model III and a great "first" soldering project. What happened to you is that one of the Rifa filter capacitors on the power supply exploded, as you can see previously in this thread. You simply need to replace it with a modern equivalent.
 
SomaCowJ said:
I am a software engineer who knows nothing about hardware.
I have fired up my Model 3 every year or two to make sure it still works.
And then it exploded. Pop, flash, smoke.
Where could I ship it for diagnosis and repairs? You guys seem quite knowledgeable.
Thanks so much if you can help!
Click to expand...
Hi SomaCowJ
We need to know where you live :- Country - State etc
We may have somebody around the corner.

Ray
 
Or, please let me know the your preferred method for contacing you, especially ChromeDome, since it looks like he may be near me.

Thanks again!
 
SomaCowJ said:
I am a software engineer who knows nothing about hardware.
I have fired up my Model 3 every year or two to make sure it still works.
Now that my grandkids are old enough to appreciate it, I brought it out, showed them some simple programs they could enter themselves, and played a couple of games. I was so excited to share this with the littles, and they were loving it.

And then it exploded. Pop, flash, smoke.

Where could I ship it for diagnosis and repairs? You guys seem quite knowledgeable.

Thanks so much if you can help!
Click to expand...

Well turned out Somacowj lives near me after all. I went ahead and replaced the RIFA cap on the PS. He was very happy about it! Very nice person to deal with.
 
Let me tell you guys something: you are heroes.

I won't bore you with the details of why my TRS-80 Model III has such sentimental value to me, but it does.
So, when it blew up a few weeks ago, I truly despaired.

What would be the chances that there were still people around who could repair such an "ancient" machine, or that the parts would be available, or that I could afford it, or that they would even be on my side of the world?
Then I happened upon this VCF forum.

Thanks to you, I found a hero you may know as Chromedome45.
He recognized the problem with my Model III from my inexpert description, already had the parts to repair it, and lives only 14 miles from my home! "Incontheivable!", to quote The Princess Bride.

I am greatly indebted to him, and to the forum. Thank you so much for all you do.

And did I mention, hooray!?
 
SomaCowJ said:
Let me tell you guys something: you are heroes.

I won't bore you with the details of why my TRS-80 Model III has such sentimental value to me, but it does.
So, when it blew up a few weeks ago, I truly despaired.

What would be the chances that there were still people around who could repair such an "ancient" machine, or that the parts would be available, or that I could afford it, or that they would even be on my side of the world?
Then I happened upon this VCF forum.

Thanks to you, I found a hero you may know as Chromedome45.
He recognized the problem with my Model III from my inexpert description, already had the parts to repair it, and lives only 14 miles from my home! "Incontheivable!", to quote The Princess Bride.

I am greatly indebted to him, and to the forum. Thank you so much for all you do.

And did I mention, hooray!?
Click to expand...

Now don't go giving Chromedome45 a big head now. We'll never hear the end of it! :)

Seriously, he's a good guy and credit to the community. I'm glad to hear your Model III is up and running again and that you can continue to share it with the younger generation.

Ok, now that we're done hijacking Clint's thread...
 
Big head who me? Yeah it's hard to fit through a doorway right now.

OK Clint sorry to have been part of the hijack. So please let us know how your project is going. Would like to know latest updates
 
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