Hi,
can you help me to question the validity of circled elements in the picture?
I have to remove them from the board?

 

they are thyristors, no datasheet available, is it for a sewing machine?

 

What do you mean by "question the validity"? Are you trying to identify the parts or test them. What does the board do?

The parts probably are bipolar power transistors. They could be other things (MOSFET, TRIAC, SCR, etc.), but probably not given the board layout and when the board was produced.

ak

 

yes, that is part of of sewing machine, called variostop. Controls the rotation of electric motors and needle position .. I think that is produced in the eighties, which means that it is quite old.
trying to find out what is this that I rounded in the picture. how it works. I can not find any information according to what is written on them. how to examine is it ok?

sorry for the bad / poor English

 

Seems pretty similar to this old thread:

http://forum.allaboutcircuits.com/t...47-i-cant-find-datasheet-for-this-part.69121/

 

here are a little different labels ..
second variostop.

 

here are a little different labels ..
second variostop.

Those look like house coded parts - the manufacturer wants you to call out their engineer, who'd probably just swap out the board without any attempt at fault finding.

You could try Google for a schematic, and maybe see if there's any appropriate technical forums for that type of appliance.

There may be no other option than trace out the circuit and make an educated guess whether those TO220 devices are transistors, MOSFETs, SCRs or triacs. Usually in that situation, I sketch the TO220 outline and draw the lines to/from it unil I can identify what goes where - that often makes it apparent what type of device it is.

The darker one in the middle with the PH brand on it looks like a bipolar transistor with a regular part number, but the photo has a bit of glare and I couldn't be sure I was reading it clearly.