Power supply cord broken

[SarahLJP]

I recently bought a 7800 off eBay. It was working for a while but then it was working sporadically. Then just a few days ago not at all. I'm not experienced with electronics, but I opened it up to see if something would jump out at me, like blown capacitors, nothing. I finally examined the power supply or AC adapter. I noticed the cord was damaged. As frustrating as it is at least I know the problem now. The not knowing was frustrating me the must.

 

I don't know what to do. Can the housing be opened? Should I attempt a repair? This seems to be a common failure point. I noticed a replacement power supply on eBay and it looks like it was repaired in the same location.

[+slx]

Best Electronics sells really new PSUs. Repairing can be quite a chore as they are usually welded shut and need to be pried open.

[+save2600]

Relatively easy fix... using an X-acto or razor blade, cut away part of that stress relief to expose the wiring within. Strip a little off the insulation, solder the wires together (observing polarity of course - do not cross the streams!), then tape or heat-shrink tube up and you're done. No need to open the power supply at all.

[+-^CrossBow^-]

Can also just cut that part of completely and solder/splice in a newer section of wire with the plug end on it. Console5 sells the wires in their store. They were mainly for splicing and using with other PSUs that meet the same ratings, but could be used for this situation as well.

 

https://console5.com/store/atari-7800-pigtail-dc-cable-and-plug-for-custom-power-supply-5-foot-1-5m.html

 

 

[SarahLJP]

Thanks for the suggestions. I'm very inexperienced with electronics repairs. I'm going to consider your suggestion CrossBow. I was about to try my hand at installing the UAV AV mod in it. Before this happened. I've been watching your videos on installation. I'll definitely be careful to watch the polarity.

Edited March 26, 2020 by SarahLJP

[+Stephen Moss]

That break is fairly common. The strain refile is there to stop it happening where it exits the case but then people wrap the cable round the power unit when them put it away bending the cable right at eh strain relief instead of leaving at least a couple of finger widths  before bending the cable over.

 

You could buy a new cable but as you will need to cut the case open (not designed to be repaired) to solder it to the PCB anyway why bother when you can use the one you already have (cut it off an inch or two below the damaged section).

Replacing the strain relief to prevent cable damage where it exits the case is the tricky part. If you have access to heatshrink and a heat source you could put layer after layer on until it fill the opening, alternatively Hellerman sleeves would work, but you need the lube and pliers as well go get them on.  

A small cable tie if you can get it on the cable just inside the exit from the case will help prevent the cable being pulled out.

[+DrVenkman]

You can also do what others suggest (I think @CPUWIZ has mentioned this a time or two) and remove the original wonky keyed connector from the PCB, install a barrel jack and then just get a bog-standard 9VDC power supply that matches the barrel jack. Doing that for my UAV-modded daily-driver 7800 is on my list to take care of someday. 

[+-^CrossBow^-]

42 minutes ago, DrVenkman said:

You can also do what others suggest (I think @CPUWIZ has mentioned this a time or two) and remove the original wonky keyed connector from the PCB, install a barrel jack and then just get a bog-standard 9VDC power supply that matches the barrel jack. Doing that for my UAV-modded daily-driver 7800 is on my list to take care of someday. 

And if you wire it in parallel without removing the original, then you could use either or.

[0078265317]

CZroe fixed mine so I guess its doable.

[Shawn]

On 3/27/2020 at 10:44 AM, -^CrossBow^- said:

And if you wire it in parallel without removing the original, then you could use either or.

 

Bingo!