Manta Posted August 27, 2011 Share Posted August 27, 2011 Hi I have been measuring the voltages of my power supply for my low boy Jamma. I get the following results +12v - 11.02 -5- -4.6v +5v15amp 5.2v Does this look about right? Link to comment Share on other sites More sharing options...
0 Homepin Posted August 27, 2011 Share Posted August 27, 2011 Yes it looks pretty right BUT you should be measuring the voltages (at the very least) right at the edge connector of the PCB rather than at the power supply itself and even better across a chip on the far end of the PCB away from the supply connector as there will be all sorts of voltage drops through connectors and wiring. Never bother much about the -5V rail as it will rarely be -5V, same goes for the +12V it is only used (in most cases) for the audio amplifier so it isn't that critical. The one to be concerned with is the +5V Link to comment Share on other sites More sharing options...
0 Manta Posted August 27, 2011 Author Share Posted August 27, 2011 Ok great I will have a look at that one. Thanks for the info Link to comment Share on other sites More sharing options...
0 MangledLeg Posted August 29, 2011 Share Posted August 29, 2011 For the +5v (which Homepin noted is the critical value), what I normally do is power on the PSU without a board and dial it to almost exactly +5v on the harness. Then I hook up the board and test again - it normally dips a little, so adjust again reading off the edge connector, or at the end of the board. Get it as close to +5v as possible, most don't recommend going as high as +5.2v once a board's connected. If you're finding a big dip in the voltage, consider running more wiring to the +5v on the PSU. I've had issues in the past and Womble pointed the way - I upped the amount of cabling between the +5v pins on the JAMMA harness and the PSU, and all my power issues were solved :) Link to comment Share on other sites More sharing options...
0 Manta Posted August 29, 2011 Author Share Posted August 29, 2011 Will give that a go. Will it matter if I accidentally press another pin on the Jamma harness with the multi meter? I imagine not Link to comment Share on other sites More sharing options...
0 Womble Posted August 29, 2011 Share Posted August 29, 2011 No, but if you short between pins it could get interesting. Link to comment Share on other sites More sharing options...
0 Manta Posted August 29, 2011 Author Share Posted August 29, 2011 Cool will disconnect the PCb first time around Link to comment Share on other sites More sharing options...
Question
Manta
Hi
I have been measuring the voltages of my power supply for my low boy Jamma. I get the following results
+12v - 11.02
-5- -4.6v
+5v15amp 5.2v
Does this look about right?
Link to comment
Share on other sites
6 answers to this question
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now