troubleshooting circuit boards

[keeganJacobs]

Hi guys, i have a associate degree in electronics but need help on learning how to troubleshoot circuit boards using schematics. Any study guide out there or good books on troubleshooting circuit boards with or without schematics?

 

[mvs sarma]

Hi guys, i have a associate degree in electronics but need help on learning how to troubleshoot circuit boards using schematics. Any study guide out there or good books on troubleshooting circuit boards with or without schematics?

Hai KeeganJacobs !
WELCOME to electro-Tech-online,

Only the service manuals for a given product can guide you. there are enormous circuits in the world.

Perhaps a text book like "Principles of Electronics" by A.P Malvino --a McGraw Hill publication might be of good healp for analog and general electronics,

Digital principles by Malvino and Leach is a known book of earlier decades. Perhaps some new books would have been published later.

Another book that comes to mind is Practical Elelctronics handbook by IAN R. SINCLAIR AND JOHN DUNTON - a NEWNESS publication withtheir 6th edition as late as 2007. the ref is
ISBN 13: 978-0-75-068071-4
ISBN 10: 0-75-068071-7
All the best.

 

[keeganJacobs]

THanks mvs sarma. Actually was looking for a book that just disects schematics. For instance at work I have a circuit board im working on and im stuck on it. 115Vac is getting rectified and the output coming out of the bridge rectifier is around 65Vdc on a good board. When i measure the bad board , the output is around 45Vdc.

THe problem is this...voltage coming out is going to different locations on different sheets and all of those areas are failing with 45Vdc but is there some kind of way we can have a short cut because it would take too long to measure each component where its failing on different sheets.

I will post the schematic.

 

[mvs sarma]

THanks mvs sarma. Actually was looking for a book that just disects schematics. For instance at work I have a circuit board im working on and im stuck on it. 115Vac is getting rectified and the output coming out of the bridge rectifier is around 65Vdc on a good board. When i measure the bad board , the output is around 45Vdc.

THe problem is this...voltage coming out is going to different locations on different sheets and all of those areas are failing with 45Vdc but is there some kind of way we can have a short cut because it would take too long to measure each component where its failing on different sheets.

I will post the schematic.

is it with a step down transformer? can you disconnect the secondary winding to the bridge and then check whether one of the diodes is open by using a dmm(digital multimeter) in diode range. low voltage is then possible. Even of the bridge is a moulded one, you may take it out of circuit and check and then put back provided you have resources.

If the entire supply is SMPS, the trouble shooting approach is different
it would be RISKY to handle the smps due to shock and many times shock can be FATAL-- please take this as caution.

 

[ROC7]

its probably a bad diode in your rectifier. if 45 is going to (everywhere after it) than its probably in your rectifier. becareful checking these.