Jump to content
IGNORED

Power supply low current?


mickcris

Recommended Posts

I bought a roller controller and it came with a power supply. It does not power on my system (no video output) for some reason though. The led that I installed on the 5v line is working fine, but the blue led on my atarimax cart only flashes for a second and then turns off. The led should flash and then flash for a bit longer when its reading the SD card. I also tried a real Donkey Kong cartridge and had no video output either.

 

I measured the power supply and all 3 voltages are present so I'm thinking it must not be putting out enough current. Has anyone had this happen before and know what component needs replacing in the power supply?

 

thanks

Link to comment
Share on other sites

replace the electrolytic capacitors in the power supply.

 

this will fix low current issues, it will also fix low voltage issues.

 

and if you want to do an accurate test for testing voltages then measure the voltages with it plugged

in to the colecovision and powered on.

 

you need a load on the power supply to get the correct readings.

  • Like 1
Link to comment
Share on other sites

Thanks for the reply. Yeah, I should have done it under load, but I really dont want to have to take the console apart again as I had a hard time getting it back together last time. I will take a look at the caps. I dont really need the supply, but it would be nice to have a backup.

 

edit:

pulled it apart and c1 and c2 had leaked. Did not check the smaller ones yet but they look ok at 1st glance.

Edited by mickcris
Link to comment
Share on other sites

I made sure to select ones that are at least 5000 hours when i was searching. going to cost $11 for the caps from mouser with shipping. just debating on whether its worth it or not to try and fix it.

 

edit:

after I pulled them all out i measured them. Only the 3 largest ones were bad (4700uf and the 2 1000uf). The 3 small 22uf and the 220uf were ok, but im going to replace them anyway if I replace the others.

Edited by mickcris
Link to comment
Share on other sites

unfortunately the capacitance test on a volt ohm meter only tests value.

 

to get a true test you need an esr meter or an expensive sencore lc meter (which I have).

 

esr meters will measure the low resistance value of the cap and give you a value, some esr meters

will give you a good/bad reading others have a chart you have to look at to determine if it's within tolerance

or not.

 

you can have a good value reading and still have a bad capacitor with leakage. and leakage is what your

trying to avoid.

Link to comment
Share on other sites

caps are cheap, go with your plan and replace them all, for smoothing and decoupling applications getting identical replacements (like ESR, ripple, impedance), is not critical

 

it only took me one experience to just bite the bullet, when I replaced a cap on my video card, and the next week another one blew and it took out more than the cap when it did

Edited by Osgeld
Link to comment
Share on other sites

I decided to replace the caps. Just installed them and it still will not power on the console. Still reading all the correct voltages with it just plugged into the wall. I did not measure it under load. I assume now that one one the voltage regulators is not supplying enough voltage under load. I may check on those or just trash the thing. I should have ordered those while i was ordering the caps just in case. gonna be another 5 bucks in shipping now.

Edited by mickcris
Link to comment
Share on other sites

  • 2 weeks later...

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...
  • Recently Browsing   0 members

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