Maker Pro
Maker Pro

Need help troubleshooting pcb relay

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
Ok update. I replaced the relay and it is actually working now...everything is good but that does not mean I'm out of the woods. I replaced the relay because I ordered it from China a month ago before I came here for help....so I figured mind as well throw it in there....

Now when I initially got this for free I came back and turned it on and couldn't believe that it was working fine....why would someone give this away for free?! Well it only lasted about 10 hours as I woke up the next day and the unit had stopped cooling completley....that's what got me digging around trying to find the issue....

My point in all this is this new relay could potentially be not fixing anything and just the month sitting caused it to work and not the actual replacement relay....OR perhaps the new relay did fix it. After all when I did test the relay on the board I jumped it (heard it click) and tested for continuity on load side and not get any....if this ends up only cooling for 10 hours again and not working then obviously it was never the relay...but what could cause something to be good for a while and then stop working....are transistors effected by heat?

I'm not getting my hopes up on this...it's great it's working now but when I got it, it was also working (lady said it didn't)....so when it sits for a long time it ends up working again....UNLESS this time it stays cooling for more than 10 hours....


I'm just trying to get a heads up on what to do/look for if it is again not working tomorrow morning....I guess follow through with the transistor tests....
 

H2814D

Nov 4, 2017
215
Joined
Nov 4, 2017
Messages
215
Ok update. I replaced the relay and it is actually working now...everything is good but that does not mean I'm out of the woods. I replaced the relay because I ordered it from China a month ago before I came here for help....so I figured mind as well throw it in there....

Now when I initially got this for free I came back and turned it on and couldn't believe that it was working fine....why would someone give this away for free?! Well it only lasted about 10 hours as I woke up the next day and the unit had stopped cooling completley....that's what got me digging around trying to find the issue....

My point in all this is this new relay could potentially be not fixing anything and just the month sitting caused it to work and not the actual replacement relay....OR perhaps the new relay did fix it. After all when I did test the relay on the board I jumped it (heard it click) and tested for continuity on load side and not get any....if this ends up only cooling for 10 hours again and not working then obviously it was never the relay...but what could cause something to be good for a while and then stop working....are transistors effected by heat?

I'm not getting my hopes up on this...it's great it's working now but when I got it, it was also working (lady said it didn't)....so when it sits for a long time it ends up working again....UNLESS this time it stays cooling for more than 10 hours....


I'm just trying to get a heads up on what to do/look for if it is again not working tomorrow morning....I guess follow through with the transistor tests....
Have you checked all of those solder joints? Since you were able to get it working for a little while, because you SOLDERED something, that may have been the issue all along. Check ALL of the soldered pins on the soldered side of that board. If you can take very clear pictures of that side of the board, we may be able to see the problem.

Wait, I may have misunderstood. It's working now? If so...leave it alone.:)
 

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
Have you checked all of those solder joints? Since you were able to get it working for a little while, because you SOLDERED something, that may have been the issue all along. Check ALL of the soldered pins on the soldered side of that board. If you can take very clear pictures of that side of the board, we may be able to see the problem.

Wait, I may have misunderstood. It's working now? If so...leave it alone.:)
Yeah I kept rambling on in my post...I'll try to keep it short and to the point here...

Got this for free because lady said it doesn't cool. I'm assuming she had it sitting for a while because it wasn't cooling....

Brought it home and plugged in and it worked...I'm thinking this lady is crazy and there is no issue...great got a free wine cooler that needs no work done to it!

Next morning I realized it didn't stay cool....went back up to room temp....

Checked relay on board (saw 12v on one end and 6v on other) so was very confused with that but went ahead and applied 12v to it with machine off just to check if it would click and close the contacts on the load side...I checked the load side for continuity and there was no continuity....so I figured the relay was shot and ordered one from China...while waiting for it I posted here about the whole 12v one one end and 6v on other end issue and it lead me to the transistor being the issue.

I still think I might not be out of the woods yet with this ...reason being is I let this sit for about 3 weeks while waiting for the relay to come in....and this lady also had this thing sitting....seems like maybe letting it sit causes something to possibly cool off or something enough to start working again....or I actually did fix the issue by replacing the relay (after all I was not getting continuity on load side when I applied 12v to coil manually)
 

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
Ok update from the update...bad news...the relay started sparking....It was fine for about 1.5 hours....

Everything works great until it gets to temperature and then has to kick on again...when it kicks on again it starts making a rattling noise (sparks are flying inside the relay)

Is there anything other than bad solder (my first time soldering) that could cause this issue? Could a bad transistor cause some type of issue with relay doing this?

I'm narrowing this down to 4 possibilities....please tell me if there are more or which is most likely...I personally think number 1 is the most likely...

1. Transistor is failing causing a weak magnetic pull on the load side....load side connects but not like it should resulting in arching/sparking

2. Compressor is on its way out drawing too much amperage

3. Bad solder joints (only my 2nd time soldering but I believe that isn't the issue because the joints really aren't all that bad)

4. Installed the wrong relay (highly doubt this but will double check the amperage/volt rating with the old one and new one)
 
Last edited:

Minder

Apr 24, 2015
3,478
Joined
Apr 24, 2015
Messages
3,478
Not saying this is the cause of your problem, but something to keep in mind with these sealed relays, they often have a small dimpled pip in the top either in one corner or in the centre of the relay.
For high switching loads it pays to open this dimple , they are usually kept sealed during the fluxing of the board process, but should be opened once in use to prevent ionization of the internal air of the relay.
 

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
Not saying this is the cause of your problem, but something to keep in mind with these sealed relays, they often have a small dimpled pip in the top either in one corner or in the centre of the relay.
For high switching loads it pays to open this dimple , they are usually kept sealed during the fluxing of the board process, but should be opened once in use to prevent ionization of the internal air of the relay.
There is a little slot that is already open...that's how I saw the sparking inside the relay...through that tiny little slit...
 

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
Ok another update....I tested voltage again....still getting the crappy 6 volts at the transistor end of coil...full 12vdc at supply end....bottom line is I fixed nothing yet haha...but I did learn about soldering....

Anyways I also tested base voltage at the transistor.....supposed to be .7v or higher I'm strongly assuming based on everything I have read....well I'm getting .5 volts....

Now could this low voltage be something related internally to the transistor causing it to bleed down? Or does this test rule out the transistor as the problem and I have a problem with whatever is feeding the transistor its voltage supply....a faulty thermostat? Just trying to see where to go from here....while I am learning a lot...this is still over my head and I don't know what all could possibly cause the low voltage seen at the transistor...
 

Delta Prime

Jul 29, 2020
1,979
Joined
Jul 29, 2020
Messages
1,979
supposed to be .7v or higher I'm strongly assuming based on everything I have read....well I'm getting .5 volts....
Says who!
This is what you're doing kiddo! Now how about a thumbs up please
Where did you read that I'm going to have to have a talk with them.
It will vary anywhere from 0.4V to 0.8V it will depends on many factor
Your meter mostly if you have it on diode test even if you apply voltage and taking a reading on the voltage setting DC. The Emitter is usually connected to a common point in the circuit which is 0 volts in this case or ground and that's a whole other can of worms "ground" take little bites chew thoroughly so you may digest the information.


photo_1686439900896.png
 
Last edited:

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
Says who!
This is what you're doing kiddo! Now how about a thumbs up please


View attachment 59469
Ok then maybe it isn't supposed to be .7? I just thought from all the help I'm getting and from what I been reading it's supposed to be .7v

Be nice if I could find a spec sheet on everything....then I can just know if something is good or not...

If the .5 volts I'm seeing is normal then I will look elsewhere...one thing that I'm getting from EVERYBODY is that 6v on one end of the coil is NOT good. I saw that on the datasheet for my relay...so I guess it just comes down to changing out this transistor and calling it a day
 

Delta Prime

Jul 29, 2020
1,979
Joined
Jul 29, 2020
Messages
1,979
I jumped in right the last post you made so just keep what I said in mind it may
Not be specific to what you are doing your application cuz I don't know where you're taking your measurements I just saw .7V and thought automatically you're measuring as the picture I posted. Still didn't hit the thumbs up. Don't blame you
 

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
I jumped in right the last post you made so just keep what I said in mind it may
Not be specific to what you are doing your application cuz I don't know where you're taking your measurements I just saw .7V and thought automatically you're measuring as the picture I posted. Still didn't hit the thumbs up. Don't blame you
Sorry man jumped in pool with my daughter....

I actually measured from a ground point straight to the base of the relay coil that is causing me problems....I thought base voltage should be at least .7v

Maybe I'm wrong...I'm ok with being wrong...I'm 40 years old but this is all brand new to me...so it would be normal at this point for me to be wrong way more often that I am right....i would love to know if .5v is adequate though so I can further troubleshoot accordingly....Is there a general rule of thumb for NPN transistors driving a 12v relay for voltage? Or somewhere I can find specs...the transistor is a c1815 gr011

If base voltage is ok then I'm just simply going to swap out this transistor and see what happens....I really don't wanna run this much more and do more damage to the relays with further tests but I guess if I have to I will...I got an adequate amount of readings done....

So my main question is if in fact the .5v is inadequate voltage....where do I look for the problem? Any further testing I can do?
 

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
Just FYI because I'm here simply looking for help....i tested for dc volts...black probe to ground and red probe to base of transistor....got .5v
 

Delta Prime

Jul 29, 2020
1,979
Joined
Jul 29, 2020
Messages
1,979
Now now the obvious question is what is the input voltage? I have driven it with 12 volts on the input or 6 volts on the input it all depends on your transistor and your circuit I need to see a schematic but you have probably already posted one I just wanted to hit this thread not marry it.
I only say that cuz you stated your age. I know I got to keep the joking down it was a joke so allow me some time to read your thread in its entirety so I may better give you my opinion.
For right now dinner's on the table and I got to get to it! Thank you for understanding. Three likes would be nice thumbs up yes I am shameless

photo_1686447173506.png
 
Last edited:

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
Now now the obvious question is what is the input voltage? I have driven it with 12 volts on the input or 6 volts on the input it all depends on your transistor and your circuit I need to see a schematic but you have probably already posted one I just wanted to hit this thread not marry it.

View attachment 59470
Now now the obvious question is what is the input voltage? I have driven it with 12 volts on the input or 6 volts on the input it all depends on your transistor and your circuit I need to see a schematic but you have probably already posted one I just wanted to hit this thread not marry it.

View attachment 59470
That looks about right to me....it is a 12v coil...seeing 6v on other side is obviously my issue...

I am a complete novice to this...just like when you first learn to ride a bike you look funny because you can't get it right away....

I'm completely confused at this point. I have read that silicone transistors need around .7v to turn on and work correctly. If this is in fact a silicone transistor and I am only getting .5v then obviously that is not up to spec....question would be if this is in fact low where would I test next?
 

Delta Prime

Jul 29, 2020
1,979
Joined
Jul 29, 2020
Messages
1,979
am troubleshooting a relay that i think is bad on a circuit board for a wine cooler....

I am getting 120 vac to one leg of the load but not getting 120 vac to other leg which gives power to the compressor.

All right good sir I say this respectfully you're giving my colleagues the runaround (independent of by design or unintentional) that stops here. Make model serial number of your wine cooler
Where are you located geographical location show me a setup how do you have it plugged where you're making measurements on this compressor. I want to see real time the meter you're using the test leads in your hand the display of the meter if you must ask family members for assistance to take photos.
No more asking question for now please. you will follow my lead if you wish to diagnose this piece of equipment it will be done safely. It should take no more than five posts to resolve your issues.
And you got to hit the like button five times now!
 
Last edited:

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
All right good sir I say this respectfully you're giving my colleagues the runaround (independent of by design or unintentional) that stops here. Make model serial number of your wine cooler
Where are you located geographical location show me a setup how do you have it plugged where you're making measurements on this compressor. I want to see real time the meter you're using the test leads in your hand the display of the meter if you must ask family members for assistance to take photos.
No more asking question for now please. you will follow my lead if you wish to diagnose this piece of equipment it will be done safely. It should take no more than five posts to resolve your issues.
And you got to hit the like button five times
All right good sir I say this respectfully you're giving my colleagues the runaround (independent of by design or unintentional) that stops here. Make model serial number of your wine cooler
Where are you located geographical location show me a setup how do you have it plugged where you're making measurements on this compressor. I want to see real time the meter you're using the test leads in your hand the display of the meter if you must ask family members for assistance to take photos.
No more asking question for now please. you will follow my lead if you wish to diagnose this piece of equipment it will be done safely. It should take no more than five posts to resolve your issues.
And you got to hit the like button five times now!
All right good sir I say this respectfully you're giving my colleagues the runaround (independent of by design or unintentional) that stops here. Make model serial number of your wine cooler
Where are you located geographical location show me a setup how do you have it plugged where you're making measurements on this compressor. I want to see real time the meter you're using the test leads in your hand the display of the meter if you must ask family members for assistance to take photos.
No more asking question for now please. you will follow my lead if you wish to diagnose this piece of equipment it will be done safely. It should take no more than five posts to resolve your issues.
And you got to hit the like button five times now!
No more asking questions haha...instead of the like button I will hit the ignore button on you
 

Macknumber9

Jun 7, 2023
24
Joined
Jun 7, 2023
Messages
24
All right good sir I say this respectfully you're giving my colleagues the runaround (independent of by design or unintentional) that stops here. Make model serial number of your wine cooler
Where are you located geographical location show me a setup how do you have it plugged where you're making measurements on this compressor. I want to see real time the meter you're using the test leads in your hand the display of the meter if you must ask family members for assistance to take photos.
No more asking question for now please. you will follow my lead if you wish to diagnose this piece of equipment it will be done safely. It should take no more than five posts to resolve your issues.
And you got to hit the like button five times now!
Haha no more asking questions....I will hit the ignore button rather than the like button with you. You have an ego problem.
 

H2814D

Nov 4, 2017
215
Joined
Nov 4, 2017
Messages
215
Haha no more asking questions....I will hit the ignore button rather than the like button with you. You have an ego problem.
Mack. Take very clear photographs of the soldered side of that board and post them for examination please. Even go so far as to take quadrant photos, if you can, but they need to be clear. Stop messing with everything else until we get those picture please. Cold/broken solder joints cause voltage problems in other places. If you can get those photos posted, we may be able to help you find them.
 
Top