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OhkaBaka

CoCo3 Green Screen of Death

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I found my 10 year old retro tech aficionado and burgeoning programmer using a CoCo3 emulator online to run BASIC programs and I said to him, "You know I still HAVE my CoCo." With tremendous pride on my part and stammering and delight and delight from him, he asked if we could set it up.

I couldn't be happier, the CoCo literally changed my life. It is mentioned in the cover letter that got me my last few development jobs.

I have kept it faithfully since I was only a couple years older than him. I used it, daily at first, and then less so, until about 1992, when I "replaced" it with a 286sx and respectfully boxed it up and tucked it away.

25 years and nearly a dozen moves later, my boy and I opened it up like we were unboxing a new VR headset rig or something. It was exciting and fun.

 

It was also completely covered in mouse poop. Sigh.

 

We cleaned it up... which included dismantling the keyboard and dumping the key springs all over the kitchen floor. BUT... it looks like Mickey had lived most of his life on the F1 and F2 keys (which were miserable to clean), and miraculously, no urine or poop managed to make it onto the motherboard itself.

 

Finally we plugged it in and my nostalgic heart soared at seeing that familiar green square appear on screen... and then sank again as I realized no text appeared on screen with it.

 

TLDR;
Upon plugging in a CoCo3 that has been in storage for 25 years, it boots to a green screen with no text or prompt. Obviously, it is still doing SOMETHING... it just isn't getting all the way up.

Carts don't work either... I get the same green screen booting to BASIC or trying to load a cart.

It could be tragic... it could be minor... I just thought I'd ask whatever is left of the Tandy community if anyone knows what it could be or has fixed such a thing before.

 

Many thanks, my brethren of the blinky rainbow cursor...

OhkaBaka

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You might want to speak to Mark at www.cloud9tech.com and speak about a repair.

 

As for what it could be, maybe someone else can chime in on that. I have no idea. With mice having lived in the thing it could be anything...

 

I also found this link (on ebay no less) that may or may not be useful:

 

http://www.ebay.com/gds/Repairing-A-Defective-TRS-80-CoCo-3-Color-Computer-EASY-/10000000002136630/g.html

 

According to that article, your easiest attempt right now would be to carefully remove the socketed GIME chip and clean the contacts..and place it back in the CORRECT orientation. I would highly suggest using a PLCC extractor for this (they can be had on Amazon for $5) as to not damage the socket. Maybe a mouse pee'd in it :)

 

Most of all, try not to cause any damage to this while working on it. CoCo3 models are not super common nowadays and their value has gone way up. If in doubt, again consider contacting Mark at Cloud9 for a repair. He will get it working (and cleaned/refurbished if you chose that option) for you.

Edited by eightbit

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That is what I'm looking for... I'll give cleaning the GIME a go... and then decide if I send her off for repairs, or put her to rest.

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Try reseating all the chips or pushing them down to make sure they are snuggly in place. This happened to one my coco 3's and it booted up properly after that.

 

Also if there was a mouse in there, is anything chewed?

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Welcome Back to the CoCo Realm...

 

I am actually very new to the CoCo, only 5 years now..

 

 

Make Sure that ANY Socked chips are Firmly in place..

 

Over the years, Oxide will build up between the Socked Chips and the Sockets..

 

I received a couple years ago a Non Working CoCo 1, with the purchase of a working CoCo 2..

 

The CoCo 1 worked, once I received it... I assume that ALL the Jostling in Shipping cause the Connections to be made..

 

 

MarkO

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If he's got money to burn, he could try the new style 512K RAM expansion in there and eliminate one possibility (since the old RAM ends up being disconnected in the installation process).

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I haven't touched it in a year. Sigh.

Recently took the spawn to the Living Computer Museum here in Seattle and he got to play on one of the last handful of Apple I computers in the world.

He also got a chance to code on a CoCo as well... then... weirdly, last month at a thrift store I found an original Tandy tape drive in beautiful condition, no stains, no corrosion.... sans cable, but lo and behold I went looking and FOUND mine... apparently after my cassette player crapped out, I was wise enough to know the most valuable part of the whole deal was that little cord.

So now my son is back at me... he thinks we should pull all the chips and clean the contacts... again... and given the rarity of the GIME, I guess that makes sense. I'll try to get to this without waiting a whole nother year.

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If you are getting a solid green screen, there is at least some life in the GIME.
On the older CoCos, bad RAM or a bad CPU results in a weird pattern on the screen.
If the pattern isn't random, the CPU at least got through part of the memory test, but I haven't looked at the CoCo 3 specific startup code.

In addition to reseating the GIME, check to make sure the expansion connector doesn't have anything stuck between the pins.
Look for capacitors that have leaked (the ones that look like little cans). They can cause all kinds of weird behavior.

There are other people besides Cloud 9 that would fix it for less and will have a quicker turn around time.

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As of our tinkering with it last night (basically looking for problems and finding none, and reseating the GIME)... It seems to have degraded a bit (I'm getting no video at all), but I'm not confident in my analog to digital video connection.

 

As for the caps, none of them appear popped, and there is no visible leakage.

there are several elements (capacitors and otherwise) that appear to have blobs of glue under them, though in some cases the (especially the big caps) the glue has mostly baked/vulcanized into a dark brown gunk that flakes off.

cloud9 is doa at the moment anyhow... where else could I find a repair

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As of our tinkering with it last night (basically looking for problems and finding none, and reseating the GIME)... It seems to have degraded a bit (I'm getting no video at all), but I'm not confident in my analog to digital video connection.

 

As for the caps, none of them appear popped, and there is no visible leakage.

 

there are several elements (capacitors and otherwise) that appear to have blobs of glue under them, though in some cases the (especially the big caps) the glue has mostly baked/vulcanized into a dark brown gunk that flakes off.

 

cloud9 is doa at the moment anyhow... where else could I find a repair

email rixhard at boysontech.com

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cloud9 is doa at the moment anyhow... where else could I find a repair

 

Mark may be on vacation. He's sometimes hard to reach at the best of times. As he's fond of telling people, this is a hobby not his job so I recommend lots and lots of patience when dealing with Cloud9. Having said that, he does top notch work and service it just won't be speedy.

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Got two Color Computer 3's from Ebay a few years ago. They were used by young children, and had crayon, pencil, and glitter all over outside, and glitter and critter remains on the inside.. Cleaned the inside and outside of the computers, and re-seated the memory chips. Both of them had the CoCo 3's had the "Green Screen of death.

 

No doubt that these kids must have inserted and removed cartridges while the computers were powered. Since the cpu's are not well protected from that type of abuse, the first thoughts were to replace the cpu's , I ordered two new 6809E and socket sets from Boyson Tech. That did the trick. Computers back fully functional once again.

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I dug out one of my old Coco 3 today and a search landed me here. FWIW, my video problem was as described above, but popping GIME out and reseating it...voila! I’m greeted with the Extended Color Basic 2.0 screen. I’m a happy camper:) Now, I am hoping this FD-501 will be such an easy fix.

 

By the way, we should have a GIME replacement soonish. I haven’t checked any other sources, but their page here regarding GIME X, an FPGA GIME replacement, looks VERY promising - including new video modes :)

 

https://thezippsterzone.com/2019/03/27/gime-x/

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9 hours ago, 777ismyname said:

I dug out one of my old Coco 3 today and a search landed me here. FWIW, my video problem was as described above, but popping GIME out and reseating it...voila! I’m greeted with the Extended Color Basic 2.0 screen. I’m a happy camper:) Now, I am hoping this FD-501 will be such an easy fix.

 

By the way, we should have a GIME replacement soonish. I haven’t checked any other sources, but their page here regarding GIME X, an FPGA GIME replacement, looks VERY promising - including new video modes :)

 

https://thezippsterzone.com/2019/03/27/gime-x/

Yes we are all so excited too see this Gime X and in our coco 3's and the other bonus is that all those games that did not work on the coco 3 will now run with the new Gime x...

Btw are you a member off the facebook group for the coco computers?

 

laters

 

Briza

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I am not sure, Briza, if I am or not 🤔 I am a member of quite a few retro groups. I will look it up a little later today :) 

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On 11/25/2019 at 11:00 PM, 777ismyname said:

I am not sure, Briza, if I am or not 🤔 I am a member of quite a few retro groups. I will look it up a little later today :) 

Hopefully we will see you join the group in facebook or even the Discord group...

 

laters

 

Briza

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7 hours ago, Briza1 said:

Hopefully we will see you join the group in facebook or even the Discord group...

 

laters

 

Briza

Is this the group, Briza?

E6F65C73-2F51-4B87-978A-A986A994D179.jpeg

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2 minutes ago, MarkO said:

That's the Facebook Group...

 

Here is the Discord Server:

https://discord.gg/4J5nHXm

 

 

MarkO

Thank you, MarkO. I will check that out in a few hours :) I haven’t checked back into FB since sending that request in and can’t remember if it was approved before I logged out or not. 
 

I’ve been checking out all the goodies at CoCoWares and such, and making a list of some stuff to get pretty soon. I am ordering a DriveWire and another cheap goody or two on the 7th. At my temporary retro desk is an old PC already serving up virtual files to Atari 8 bit and Commodore 8 bit machines. Their TI 99/4A and CoCo2/3 cousins  will join them very soon :) 

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2 minutes ago, 777ismyname said:

Thank you, MarkO. I will check that out in a few hours :) I haven’t checked back into FB since sending that request in and can’t remember if it was approved before I logged out or not. 
 

I’ve been checking out all the goodies at CoCoWares and such, and making a list of some stuff to get pretty soon. I am ordering a DriveWire and another cheap goody or two on the 7th. At my temporary retro desk is an old PC already serving up virtual files to Atari 8 bit and Commodore 8 bit machines. Their TI 99/4A and CoCo2/3 cousins  will join them very soon :) 

Hello..

 

What User name on Facebook??  I can check...  On Discord, I'm an Admin...

 

I'm new to the CoCo..   2012 was my first one, now I have 8 of them plus a Tano Dragon...

 

 

MarkO

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11 minutes ago, 777ismyname said:

Thank you, MarkO. I will check that out in a few hours :) I haven’t checked back into FB since sending that request in and can’t remember if it was approved before I logged out or not. 
 

< SNIP >

https://www.facebook.com/painintheworld?fref=gm

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16 hours ago, MarkO said:

That is me :) 

 

We had TRS-80 Model 3 and the original Color Computer in school, way back when. Later on in junior high we got a bunch of CoCo 2’s and Model 4’s. By the time the CoCo 3 had come out in high school the schools had changed over to IBM PC. 
 

I’ve still got my original CoCo 2 from around 84 or 85. My first CoCo 3 didn’t come along until around 2000, when I picked one up with a disk drive and controller from a customer at my family business’ shop. It was tried out for functionality (it worked fine) and boxed up and mostly forgotten about...until a week or two ago :) The GIME had to be reseated. The disk drive isn’t working, but I’m pretty sure the cartridge slot itself is the main culprit. The drive and/or controller may need work, but the only other ROM cart I have for it doesn’t work either when plugged in. I unearthed another CoCo 3, but with a clearly defective GIME. There will probably be a transplant between them, so that I can rule some things out. When the GIME X is available I hope to be able to get one for each of them. 

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I have my original Sinclair ZX-81 from 1982 and the an Apple ][e from 1983...  I got a Commodore SX-64 in about 1986 and my first CoCo, ( a CoCo 3, NIB ) in 2012...

 

So I am a "new" CoCoNut!!

 

The CoCo Crowd is a pretty friendly group, so I keep, Hanging Out with them... ;)

 

MarkO

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