Jump to content
rbairos

Glitchy video / random characters

Recommended Posts

Hello a friend just acquired a colecovision and 2 carts (Smurf and Cabbage Patch Kids).
Cabbage patch rarely starts up, and Smurf starts up with several artefacts half the time.

Any advice how to start diagnosing?

From the little I know, it may be a DRAM issue?
In which case, I should look for dry solder joints and/or consider a DRAM update kit which foregoes the multiple voltages?

Thanks for any info,

Rob.

 

597896367.jpg

597896427.jpg

597896473.jpg

597896662.jpg

597896886.jpg

Share this post


Link to post
Share on other sites

My Coleco did exactly what you showed in the first picture.  This is what I did to fix it.

Clean the cartridge slot with some electric contact cleaner and a tooth brush.

Open the Coleco and clean the power switch connections with some electric contact cleaner.

Share this post


Link to post
Share on other sites

Thanks that makes a lot of sense.
Luckily I already have deoxit and isopropyl alcohol and white erasers at hand.

-Rob

Share this post


Link to post
Share on other sites

The cart contacts and the power switch are the most likely culprits.  May I suggest properly servicing the power switch if you have the tools.  Just spraying deoxit in there does nothing to (i) remove any old grease and (ii) provide lubrication for future use.  Following the attached instructions (not mine) should put your power switch back into almost as-new condition.

power_switch.pdf

  • Like 1

Share this post


Link to post
Share on other sites

My colecovision seems to be doing the same thing.  I am really not technical so maybe I will first try cleaning the cartridge contacts with some electrical contact cleaner.  If that does not work is there anyone on the boards who services the system? 

Share this post


Link to post
Share on other sites

Sorry, busy time of year, but I hope to apply these techniques very soon.
Will definitely report back.

Share this post


Link to post
Share on other sites
2 hours ago, dsullo said:

My colecovision seems to be doing the same thing.  I am really not technical so maybe I will first try cleaning the cartridge contacts with some electrical contact cleaner.  If that does not work is there anyone on the boards who services the system? 

To help find potential repair people, could you narrow down your location?  But really, cleaning the contacts in both the cartridge slot and the switch is the first line of troubleshooting.

Share this post


Link to post
Share on other sites

Ok fair enough.  I live in New Jersey USA.  I will use a toothbrush to clean the contacts of the cartridge port and see if I can figure out how to clean the power switch. Is my only guide the PDF or is there any tutorial videos ? I could not find any on YouTube? 

I will post results in the next few days

 

dustin 

Share this post


Link to post
Share on other sites
1 hour ago, dsullo said:

Ok fair enough.  I live in New Jersey USA.  I will use a toothbrush to clean the contacts of the cartridge port and see if I can figure out how to clean the power switch. Is my only guide the PDF or is there any tutorial videos ? I could not find any on YouTube? 

I will post results in the next few days

A toothbrush won't clean the cart port contacts.  You need to use something that will wipe clean the surface of the contacts.  Personally, I use plain card business cards that I spray with isopropyl alchohol or contact cleaner.  The cards need to be stacked so that they are as thick as a cart PCB edge.  Then push the card into the cart slot and remove, repeat several times.  Then repeat again with new card and more alchohol.

 

I've never seen a YouTube video for the power switch repair.  The pdf I posted gives good instructions and is what I follow when doing my power switches.

Share this post


Link to post
Share on other sites

Ok cool thanks for the tip with the business cards I will try that would you say the electrical contact cleaner is more effective than alcohol?

Share this post


Link to post
Share on other sites

Wow I can’t believe it but I opened the colecovision and used electronic  contact cleaner on the cart slot and power switch and to my amazement it actually seems to have fixed the issue.  The electronic contact cleaner seems much more effective than alcohol. 

See the nice clean image.  

9C3E7F7B-5BE1-4F2C-86F8-6D9D4765A9DF.jpeg

Share this post


Link to post
Share on other sites

dsullo, I sent you a link to a thread I made for your issue. If you wiggle the power cord I bet the problem comes back.

Share this post


Link to post
Share on other sites

Great news - congrats.

 

I would still suggest that you open up the power switch and apply some dielectric grease.  The contact cleaner will likely have dissolved any grease that was remaining there.  It will also give you the opportunity to fully clean the switch contacts.

Share this post


Link to post
Share on other sites

Congrats on getting the system working properly. I hate to be a "downer", but the issue will come back in time unless the power switch is properly refurbished and new dielectric grease applied.

 

Share this post


Link to post
Share on other sites

Alright here's the update:

Spoiler:  it works again.

What we did:

1. First we cleaned all the cartridge edges, and the connector.
We used white erases, deoxit and isopropyl alcohol.

Unfortunately same problems remained.

2. We then were able to take the case apart (just 8 screws on the bottom, without disturbing the metal front plate), though this took some careful fiddling.
We were also able to remove the shielding which luckily was just soldered on one spot, removing some easily accessible screws.

This gave access to the switch, which we just sprayed with deoxit without removing its case.
We also inspected for bad solder joints, and gave the board a gentle cleaning with a toothbrush and isopropyl alcohol.
Unfortunately same problems still remained.

3. Finally we desoldered the power switch main upper casing from the board. (Two large solder points)
This revealed six contact points, 2 of which were black, the rest yellow.
This cleaned up easily to a shiny silver color.

The problem still remained, but after a couple of switch cycles, all was finally good consistently.

So our success rate went from about 10% to 100%.

Thanks for all the tips!

Rob.



 

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...