Need help repair this pcb its the SM-04-HSC

dl324

Joined Mar 30, 2015
10,745
Welcome to AAC!

There's little chance that a member is going to be able to be familiar enough with the device you mention, so schematics, model numbers (Google didn't return anything useful for SM-04-HSC in the first dozen hits), close ups of suspect components, and a thorough description of the problem are required.

  1. Was the device in operation when it got wet?
  2. If it wasn't, was it allowed to dry completely before applying power?
  3. What does stopped working mean? Did it stop working completely? Are parts of it still functional?
  4. What are your skills for working with surface mount components?
EDIT: Add clipped, rotated image.
clipimage.jpg
 
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Thread Starter

YanisPCB

Joined May 19, 2020
2
Welcome to AAC!

There's little chance that a member is going to be able to be familiar enough with the device you mention, so schematics, model numbers (Google didn't return anything useful for SM-04-HSC in the first dozen hits), close ups of suspect components, and a thorough description of the problem are required.

  1. Was the device in operation when it got wet?
  2. If it wasn't, was it allowed to dry completely before applying power?
  3. What does stopped working mean? Did it stop working completely? Are parts of it still functional?
  4. What are your skills for working with surface mount components?
EDIT: Add clipped, rotated image.
View attachment 207603
thank you,
- yes it was working when it got wet. because this led is used in elevators, due to poor insulation the device may have been in contact with water when the concierge was servicing.
- by saying parts still functional, does using a multimeter is required to verify every part of it? and how can i test the led are working or not?
- my skills with surface mount components is limited to soldering and repairing smartphones.
Again thank you its my first post in the forum and please i insist on how can i test the led that are on the front.
 

dl324

Joined Mar 30, 2015
10,745
by saying parts still functional, does using a multimeter is required to verify every part of it?
No. Most important parts can't be tested with a multimeter and testing in-circuit isn't straightforward. You can check transistor junctions and diodes, sometimes.
and how can i test the led are working or not?
If the forward voltage is low enough, you can use the diode checker on a DVM.

The technique for troubleshooting is the same as most other devices. Apply power and trace the circuitry back from a part that isn't working until you get the correct response.
- my skills with surface mount components is limited to soldering and repairing smartphones.
If you can work on smartphones, your skills must be pretty good. Small parts and easily damaged boards.
 
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