Jump to content
IGNORED

Colecovision PSU help


PsychoDave
 Share

Recommended Posts

Hello everyone, I've got a quick question...

 

My Colecovision doesn't turn on, that is to say when I flip the power switch I get no picture on my TV.

 

I've replaced the power switch already with a Radio Shack DPDT Rocker - 275 691. I've checked continuity

with my meter as well as voltage.

 

When I check the PSU with the system in "Off" I get all the correct voltages 12v, 5v and -5v but when I

turn the switch on the 12v rail drops to 6v. I checked voltages on the back of the plug receptacle and at the board

where the switch is connected. A 6v drop seems to be a bit excessive...

 

So, where do I go from here? Do I crack open the PSU or could there be an issue on the board?

 

Any help would be greatly appreciated.

 

Dave

 

 

 

Link to comment
Share on other sites

Cant find the edit button, sick of trying...

 

If someone can edit the 1st post to include this, awesome. If not...no worries

 

I just wanted to add that ch 3 and 4 on my tv are static...always

When I power up the Coleco there is no image, no black screen

just static.

 

I don't know if that helps...

 

Also, I'm thinking my problem could be a capacitor in the brick...

 

Dave

Link to comment
Share on other sites

It could be your powersupply or it could be something else dragging down your 12v line.

 

A crude method would be, to turn it on wait for a few seconds then touch the video ram

chips and see if one is hotter than the others. you can then start disconnecting chips from

the 12v rail till your voltage stabilizes.

Link to comment
Share on other sites

I'd bet it's the power supply. All the CV powers supplies that I've worked on that had it's original capacitors were always out of spec. I've resurrected quite a few CV power supplies by simply just recapping them.

 

attachicon.gifCV caps.png

This is good to know, but what the challenge for me is the best way to open the darn things then put them back together so they dont look like some night-before-due school project.

Link to comment
Share on other sites

This is good to know, but what the challenge for me is the best way to open the darn things then put them back together so they dont look like some night-before-due school project.

Sometimes you can get lucky and pop the plastic apart enough to start prying by applying pressure around the seem. I’ve also done it by sticking a flat blade screwdriver in between the slot for the strain relief and gently prying.

 

 

It's more likely than not you're gonna do some damage to the housing, but what’s more important it working or looking pretty.

Link to comment
Share on other sites

Apparently Radio Shack is going belly up again, unless they can find funding. As a result all sales are final and no new shipments

are coming in. After sifting through the component drawers I could only find 4 of the capacitors but they were axial, not radial.

I've ordered all the capacitors from amazon and should have them on Tuesday. Now I just need to get a dremel so I can open up the housing.

 

What have people done to close the housing back up after cutting it open? Plastic cement?

Link to comment
Share on other sites

I had a dead colecovision power supply once, I had to throw it away. i cracked it open to look into fixing it and it had grey epoxy over everything. it was not a thin coating, it was full to the brim.

it would have taken many weeks to get all that shit off which i was not prepared to do. i was a bit pissed to be honest, why do that!!!!!!

Link to comment
Share on other sites

Well, I've finished swapping out all the capacitors in the PSU. After temporarily

covering it back up and plugging it in, I've got all the correct voltages. 12 VDC,

-5 VDC and 5 VDC with no load. However, as soon as I turn the coleco on the

12v rail drops to 6v again. So, either my PSU is just bad or something else is

wrong...

 

Any Ideas? I guess ill check the video ram as suggested by cdn2a

 

Here is an album of pictures I took while swapping out the caps.

http://smg.photobucket.com/user/beaverbandit/library/Colecovision%20PSU%20Capacitor%20swap

 

Sample pic:

20170322_153411.jpg

Link to comment
Share on other sites

  • 7 months later...

I'd think it might help, as you'd be bypassing anything in the console that uses anything other than 5V? I guess it is a matter of how much you want to spend, though Console 5's five-volt mod kit is under $15.

 

At that point, an iPad charger could act as your PSU, offering more current than the old brick.

Edited by towmater
Link to comment
Share on other sites

I'd think it might help, as you'd be bypassing anything in the console that uses anything other than 5V? I guess it is a matter of how much you want to spend, though Console 5's five-volt mod kit is under $15.

 

At that point, an iPad charger could act as your PSU, offering more current than the old brick.

Fair enough, just seems like a very convoluted solution to a 3 solder point problem.

 

Sent from my Pixel 2 using Tapatalk

Edited by shabazz18
Link to comment
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.
Note: Your post will require moderator approval before it will be visible.

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...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...