# anyone know how to repare that hotplate pc 400



## ericrm (Oct 15, 2012)

i have this hotplate that a receive and hot chemical shower.... now each time i light it on it smoke from that chip(look picture)
i have send an email to corning but i doubt that i will have any succes receiveing help from them...
if someone have add the same problem or if someone knows the spec of that chip .. i would love to get my hotplate back...


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## Geo (Oct 15, 2012)

Eric, that looks like a common transistor of this type.
does it have three legs?


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## ericrm (Oct 15, 2012)

sure have... are they all the same thing?


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## Geo (Oct 15, 2012)

besides different ratings, they are all basically the same. write down any numbers and letter sequences on your bad piece and do a Google search. when you find the right piece, go to your local electronics store (Radioshack) and buy it. they are very cheap. you may have to buy a small pack with several in it as im not sure they are sold singly. unsolder the old one and solder in the new one.


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## mjgraham (Oct 15, 2012)

May be an SCR, if you can find any info left on it.


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## g_axelsson (Oct 15, 2012)

I think it can be two things. Either a thyristor (SCR) for turning on and off the power to the hot plate, or a linear power regulator, not a transistor.

You need to clean the circuit board from any traces of whatever you got into it or else your problem will return. You can use clean water and a tooth brush or similar, but don't let the water get to the transformer. Afterwards you have to dry it out really well before putting it back together again.

Can you take a close up of the component where the markings are readable, then I could probably identify it for you.

/Göran


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## ericrm (Oct 15, 2012)

i already cleaned it with water but the result didnt change my biggest problem is the fact that the marking are all gone ,not a single clue left....


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## mjgraham (Oct 15, 2012)

If I could see the bottom I could tell better, it looks close to the leads for the hotplate so I am going to guess SCR plus it is attached to a heat sink of sorts, for temp control, controls the phase angle of the power , is this a 120v or 240v unit.

Edit. Bottom of that board ..


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## qst42know (Oct 15, 2012)

You may be able to replace the board but I couldn't find a wiring schematic for the individual component.

http://googledevadmin.corning.com/Lifesciences/technical_information/techDocs/hotplate.pdf

Perhaps someone here has the same hotplate to read the numbers for you.


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## element47.5 (Oct 15, 2012)

Without the numbers on that "chip" you have a much harder task. The physical package you show is known as a "TO-220" package which is very popular among semiconductor makers because of the way it can either be attached to a heatsink, or, just stand up in the air if the power dissipation isn't too much. But the bad news is, such a physical package may be a transistor, a voltage regulator, a thyristor, an SCR, or a Triac. Need the part number, otherwise you're shooting in the dark. And unfortunately, there is a pretty decent chance that you'll fry the new one when you replace it. Because you fried something earlier in the circuit and THAT is the thing that fried your TO-220 whatever. Hopefully you can get a replacement for a few bucks, throw it in there and see if it works. Otherwise you're in for some headaches. Just the way transistor circuits are.


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## maynman1751 (Oct 15, 2012)

Just a shot in the dark, but have you made sure that the connections are clean and secure? If there is any oxidation or corrosion on the mounting surfaces it could cause high current draw causing the component to overheat. I cant tell if the tab is riveted or screwed on, but that connection looks suspect????? Also check the solder connections for good bonding. I have seen faulty connections 'fry' a lot of components.


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## its-all-a-lie (Oct 15, 2012)

You should be able to google the model number of the plate and get a wiring diagram that will tell all the components inside it. Just a thought.


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## butcher (Oct 16, 2012)

You need the numbers off of the package and get the datasheet for the component, without them it is hard to tell what it was, from looking at the picture the circuit board has a transformer and filter capacitor, besides the relay and small support components like resistors, I cannot see diode or a rectifier bridge, but then I cannot see everything from the picture, the wires coming in and out of this circuit board lead me to believe it is a power supply for the other board, and the relay may be what is switching voltage to the output Heater or load, this leads me to think the component circled is a voltage regulator for the more complicated circuit board.

edit mispelling

This could be a transistor, voltage regulator, SCR, or Triac, or several other things, this package is used for many devices the numbers on it tells what it is and what the specifications are.

Look for numbers like LM7805, Lm7812 LM7005, Etcetera; these are some numbers for voltage regulators.

Look with a good magnifying glass get the numbers.

Post the numbers of the package here.

Another option is try and find the schematic for the model of unit you have, even schematics of other models made by this company can give you clues if you cannot find the right one.

Give us model numbers and names of company who made this and what the device is called.


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## mjgraham (Oct 16, 2012)

Of course this is a lot of guess work, I might be able to tell better if I ahd a picture of the bottom of the board however I would check to make sure the heating element was not shorted, I don't know what caused the failure to start. I agree some better pictures , I am curious about that small transistor beside the relay, if that is a regulator then good chance the other is the one for the heater but with a picture of the bottom circuit could see if it is going to the heater. I don't know where is an easy place to get parts but it could be something as simple as one of these.
http://www.digikey.com/product-detail/en/TYN610RG/1026-TYN610RG-CHP/2521439
Of course there are a thousand different ones that could work.


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## ericrm (Oct 29, 2012)

thank you for all the response and sorry for the late waiting ,i bought an other one to get the part number but i dont know if it gonna be the same since theyr both look different... anyhelp will still be apreciated




would it be safe to just use the same model since it is not the same exact hotplate?


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## mjgraham (Oct 29, 2012)

yes I would , forgot about the triac , kind of like 2 SCRs back to back, of course looks to be a discontinued part or bulk only, but it is a 400V 15A Triac anything of the same or higher amps should work. Is this a 120V unit?


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## ericrm (Oct 29, 2012)

yes it is 120v


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## Geo (Oct 29, 2012)

http://www.jameco.com/1/1/1768-q4015l5-400-volt-15-amp-triac-ic-220-package.html

look on page 2-4. it a 15 amp.View attachment Q4015L5 (2).pdf


also check this one too.View attachment Q4015L5.pdf


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## mjgraham (Oct 29, 2012)

I'd say you would be good with that one, actually the one I was looking at for a project.


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## qst42know (Oct 29, 2012)

Under $2.50 for a single piece.

http://www.mouser.com/Search/Refine.aspx?Keyword=576-Q4015L5


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