Guide to Troubleshooting with a Schematic?

[Midcoastsurf]

Hello,

Is there a guide that will show me how to troubleshoot using a schematic?  I am working on a Kortek 2182 chassis and have received great feedback and help from this board, but I would still like to know how my board works and what path to follow when troubleshooting.  For example, if there is no voltage at any of the large diodes in the power supply section of the chassis, where do I start testing with my multi-meter?  Should I be tracing the lines back towards the main fuse?

Thanks

[mgb]

I'm not sure about one particular guide to working with schematics but there are a lot of good web sites with varying info on it.
If you really wanna learn some arcade repair, check out Randy Fromm's website (hopefully, its still around) There is a yearly fee but there is some great info on there. There are a bunch of videos and the big blue book of all kinds of arcade repair articles as well as the big green book of monitor schematics and repair articles.

Also be sure to check out www.therealbobroberts.net for great repair articles.

If your not getting any voltage at the large diodes in the power supply section the first place you should check is the main fuse. Check the fuse with your meter not by eye.

[Midcoastsurf]

Thanks mgb.  Yes, the fuse is good and I measure 120v at either side of the fuse clip with the other probe touching ground.  I replaced the HOT as well.

[lilshawn]

you have to power it up and see what works, instead of focusing on what's NOT working.

it's just a process of elimination. most sections of the monitor can be disconnected from the power supply to see if they are shorted or dragging things down.

usually you just lift out the diodes or the (for example L301 ) chokes on the SMPS power supply to remove power from those areas.

for example, if you cut the +14 volt and the monitor powers up (even if you have just a horizontal line, it's more that you had before), then something running off that 14 volts is dragging it down. looking at the schematic you can see the ----[+14> tags showing the voltage output you can tell the areas tagged [+14>--- show the item runs on that voltage cause the arrow points in.

what i do with all my paper copies is grab a whole mess of highlighters and mark each voltage out and input with a different color. that way i can quickly scan the schematic and find all the "blue" voltages. are my +14 volts. then i can see this, this, this, and this are all running off 14v. then i hook up the main 14 volt and continue to disconnect the small areas until i've found the culprit. testing/replacing components as need be until it operates properly.

once you eliminate what works, all you have left is what isn't.

[Gray_Area]

Really what he wanted to know, though he apparently wasn't sure, is approaches to trouble shooting. A schematic isn't a step-by-step. It's just a layout of the circuit design.

[Midcoastsurf]

Thanks gray-area...that is what I meant.