Colecovision Repair Assistance

[phuzzed]

Hi there...

 

I was given a whole bin of broken ColecoVisions and I'm trying to go through them to salvage them. I've done repair on other consoles, such as the 2600, 5200, and 7800, but this is really one of my first attempts on the ColecoVisiion.

 

First, Does anyone have the service manuals scanned? I found them on ColecoVision zone's website, but there is a Watermark on everpage that identifies the site--which makes it difficult to read.

 

Second, I have one system that works well, except that one of the controller ports in always going down, even if the controller is unplugged. Looking at the board, I see that there is a resistor pack along with a 74ls541N that feeds into somewhere that is reading the imputs. I suspect it is one of these chips, but I am not sure. I was hoping maybe someone would shed some light on their past experience getting these consoles up and running.

 

Thanks in advance!

[+evg2000]

not sure if any of this will help:

http://console5.com/wiki/Category:Coleco

[thecrypticodor]

First off make sure you're testing these units on a working power supply. Quite often people will sell their consoles thinking that they're broken and the power supply is actually the one at fault.

 

The power switches are a common failure point. They are DPDT (dual pole double throw) switches and the old dialectic grease usually dries up and leaves the copper contacts in the switch to corrode and oxidize. Quite often one or both of the 5 and 12v lines are not making it trough the switch because of this.

 

Bad Ram and controller IC's are also common. If you need to replace the ram you have to modify the system slightly as the replacements run on 5v and the originals used -5v

 

Replacement ram http://console5.com/store/parts/chips-ics/ram-chips/16kb-x-1-bit-dram-mb8118-12.html

 

Controller chips http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&pa=47870&productId=47870&cid=PDF

Edited July 30, 2014 by thecrypticodor

[phuzzed]

I'm testing with a known good power supply from my "golden" unit.

 

I need to place an order for some other electronic components, so I may just go ahead and get the 4fLs541s and swap them out to see if it fixes the issue. This is the only issue I see with the system.

[iscout62]

be careful replacing the octals, the traces lift pretty fast.