What is this part called??

[longshot21771]

I am just starting to learn more about electronics and am a late bloomer, always been interested but never took the initiative to learn like now since my job requires more repairing of certain items. Anyways I am working on a computer power supply and I removed this part and broke the end of of it and I have no clue what it is can anyone tell me so I can get another one for the power supply? The only markings on it is an M with square around it and the number 4 in one corner and 3171 one row and s ( or 5 ) 87 under that. There are supposed to be 4 prongs but I broke one accidentally. Any help would be appreciated. Here is the link to the pictures **broken link removed** Sorry about the bad quality I only had my cell available at the time. It is small part and square shaped with one side beveled and 2 prongs that connect to the power supply board on each side.

 

[HarveyH42]

LM317 adjustable voltage regulator? Useless pictures...

 

[mvs sarma]

LM317 adjustable voltage regulator? Useless pictures...

It appears a 4 pin optocoupler!!
i don,t remember to have seen LM317 in that package of 4 pins.

Even with a cellphone a portrait mode photo is possible and it comes with better clarity.

However, longshot21771 could use a sharp knife and and carefully carve small portion above the broken pin while taking care not to break other pins, and solder a wire to get access to the broken pin, if he/she could not find a replacement and provided the device is not faulty.

 

[longshot21771]

LM317 adjustable voltage regulator? Useless pictures...

Thanks for the quick response, yes I know the pics were pretty much useless for some reason the digital camera that I use for the internet alot came up missing. I actually removed another one from a power supply to use and had no issue's removing and installing it, I learned from my mistake. Appreciate the help and once I find the camera will post better pics tonight. THANKS!!

 

[duffy]

I'll bet it's a small bridge rectifier.

 

[mvs sarma]

I'll bet it's a small bridge rectifier.

in a computer power supply?

 

[dark]

I am just starting to learn more about electronics and am a late bloomer, always been interested but never took the initiative to learn like now since my job requires more repairing of certain items. Anyways I am working on a computer power supply and I removed this part and broke the end of of it and I have no clue what it is can anyone tell me so I can get another one for the power supply? The only markings on it is an M with square around it and the number 4 in one corner and 3171 one row and s ( or 5 ) 87 under that. There are supposed to be 4 prongs but I broke one accidentally. Any help would be appreciated. Here is the link to the pictures **broken link removed** Sorry about the bad quality I only had my cell available at the time. It is small part and square shaped with one side beveled and 2 prongs that connect to the power supply board on each side.

Difficult and useless to guess unless you provide a clear picture ? . Keep it inverted on your scanner glass. Then cover it with white paper and then you may post here .

 

[duffy]

in a computer power supply?

Yes, but I think you're right - looks more like an optocoupler. I've seen small bridges in there as part of a secondary supply running the regulator or standby voltage, but that fuzzy image looks more like a 4-pin optocoupler.

 

[mvs sarma]

Yes, but I think you're right - looks more like an optocoupler. I've seen small bridges in there as part of a secondary supply running the regulator or standby voltage, but that fuzzy image looks more like a 4-pin optocoupler.

He was telling it was a square one -- perhaps whether he meant a rectangular...Generally though an opto is used in SMPS, i don't remember to haveseen in ATX power supples. they have auxiliary winding and manage.

 

[alhoop]

I'm betting it is a Monsanto opto-coupler.
Al

 

[mvs sarma]

I'm betting it is a Monsanto opto-coupler.
Al

we appreciate, but why bet at all?

 

[Boncuk]

To me it looks like a very ancient thyristor.

It has only three pins, so it can't possibly be an optocoupler or a bridge rectifier.

 

[HarveyH42]

To me it looks like a very ancient thyristor.

It has only three pins, so it can't possibly be an optocoupler or a bridge rectifier.

It originally had 4 pins, on is broken off. I missed that part of the description as well.

 

[ScareCrow]

It's a contrary ratchetating frammerjammitz. Made Yugoslower.

 

[longshot21771]

Yes, but I think you're right - looks more like an optocoupler. I've seen small bridges in there as part of a secondary supply running the regulator or standby voltage, but that fuzzy image looks more like a 4-pin optocoupler.

That is exactly what it looks like except it is black, and it did come from a pc power supply. I took it to a electronics guy and he said it was a optocoupler, found one just like in your pic here out of another power supply and it worked like a charm. Thanks to everyone for you help. Another question how do you test them??

 

[duffy]

Put 10ma through the LED and see if the transistor turns on. Start with a spec sheet. Here's the one for the one in my photograph -
https://www.electro-tech-online.com/custompdfs/2009/01/4215.pdf

Yours is going to be a little different.