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Component Identification

JimB

Super Moderator
Most Helpful Member
#3
I also thing there must be a page 2 to the schematic.
There are a total of eight pages to that diagram.

Look at the bottom right hand corner where it says:
Schaltplan bl 4 von 8

This translates to English as:
Circuit Diagram page 4 of 8

JimB
 
Thread starter #4
I think the circled parts are ceramic capacitors.
I also thing there must be a page 2 to the schematic.
I have attached all the pages that have to do with the PCB. I will also like if you can tell me the equivalent of the component in through hole components. Thanks
 

Attachments

JimB

Super Moderator
Most Helpful Member
#6
Frisky2good,
Your schematic "screenshots" are mostly unreadable on my PC, the resolution of the JPG files is a bit low.

However, when I click on the original picture of the board, I can clearly see that the unknown components are adjacent to IC2, IC19, IC25 and IC30.

So if you can have a look at the schematics on your PC, and find those components, then post a higher resolution version of the appropriate schematic, then we may be able to decide on the nature of the unknown components.

JimB
 
Thread starter #7
Frisky2good,
Your schematic "screenshots" are mostly unreadable on my PC, the resolution of the JPG files is a bit low.

However, when I click on the original picture of the board, I can clearly see that the unknown components are adjacent to IC2, IC19, IC25 and IC30.

So if you can have a look at the schematics on your PC, and find those components, then post a higher resolution version of the appropriate schematic, then we may be able to decide on the nature of the unknown components.

JimB
Thanks for your effort so far. Here is a PDF version of the schematics.
 

Attachments

#8
I think the circled parts are ceramic capacitors.
I agree with Ron.

The appear to be the larger ceramic (or poly) caps associated with the voltage regulators - eg. the 470nF ones such as C49, C67, C73 on page 5 of the schematic.

You could check for continuity between the capacitor ends and ground or the relevant test point to confirm that's where they are connected.
 

ronsimpson

Well-Known Member
Most Helpful Member
#9
Here is the picture of the circled parts. Note the "IC25", IC19, IC30, IC2.
1541686324629.png
Next I used the PDF search function to find "IC25". Which is a large flash memory IC.
AND
IC2 is a AD820BR.
1541686514332.png
Are you certain the schematic = PCB?
 
Thread starter #10
Here is the picture of the circled parts. Note the "IC25", IC19, IC30, IC2.
View attachment 115089
Next I used the PDF search function to find "IC25". Which is a large flash memory IC.
AND
IC2 is a AD820BR.
View attachment 115090
Are you certain the schematic = PCB?

It's the schematic. The components are actually connected to the LM2941 POWER REGULATORS. If you can help me trace them through that I will be very happy
 

JimB

Super Moderator
Most Helpful Member
#11
Ron,
Be aware that there are two schematics in that PDF
The first scheamtic is drawing number L1.8072.2003.0
The second is drawing number L1.8072.2103.0

If you look on sheet 5 of dwg no L1.8072.2003.0 which is page 5 of the PDF, you will find:

IC19 on page 5.png



JimB
 
Thread starter #13
The regulators are on page 5 of the diagrams, the capacitors are either 470nF or 100nF, depending which regulator they are on, and if they are on the input or the output.

Why do you want to know anyway?.
They are actually 5. I got blown beyond recognition so I asked someone that has the same equipment to send me a picture of his PCB which confirmed that the missing component is similar to those other 4. I was also fortunate to find the schematic. Since there is noone around here familiar with SMDs, I decided to seek help online. I have attached the picture of the spot where the blown component was. Top right where the arrow is.
 

Attachments

Thread starter #16
Some surface mount ceramic caps made by Murata have that red body - eg. some in this list:
https://uk.rs-online.com/web/c/pass...ors/?applied-dimensions=4294965528,4293291338

Other pictures sometimes show the stronger red as with the ones on the circuit board.

Can you measure one of the good ones, the physical size in mm or fractions of an inch?
I can do that and upload the
Try a 100nF, it's most likely not very critical anyway - probably just a decoupler - does the unit work without it?.
I did not power it after blew up but I will try it tomorrow. Thanks a lot. Can I replace it with a 100nf, 15v through hole cap because SMD components are not available here?
 
#18
Yes, just stick a normal cap across the pads.
... But try to clean the area as best you can first, to remove all the blackened stuff and any possible conductive fragments that could cause further problems..

Use a cloth with a trace of alcohol, an old toothbrush, a pencil eraser or whatever you can to try and get the PCB as as clean as possible before adding new parts.
 

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