Whirlpool dryer control board

[Eaglecrest]

I have a Whirlpool dryer that runs for a while then stops with a blinking timer screen. The dryer can't be reset by hitting any input and if you pull the plug and plug it back in it also won't respond. Light is on in the drum when you open the door, but no other sign of life. If I leave it unplugged for a period of time, which is multiple days, it runs again. May be able to get a load done, but now seems to be less than full load before it errors out.

Since unplugging will get it to work, I am assuming that there is an error condition that is causing the onboard processor to shut down the dryer (condition stored in memory) and then removing power lets the circuit drain and causes a reset. There is no error code given and checking on line the blinking screen seems to indicate a control board failure. While many things could be causing this, I looked at the board and there is a burnt pad under the relay. I don't recall this earlier, even though the same problem existed; however, at that time power resetting could last for weeks to months, so I am thinking that whatever is happening (bad solder joint?) has gotten worse and that is why it now works but only for a short time after reset.

Does this seem to make sense from an electronics POV? If the joint is bad can I run a wire from the relay lead to the power connector, in effect replacing the trace with a wire connection?

[stj]

that could have been caused by bad sofering OR bad relay contacts.
either way, you have to remove the relay,clean the board and ideally fit a new not-cooked relay.
otherwise the control board will know the motor isnt being powered.

[Eaglecrest]

If I understand your comment correctly, if the relay is bad then hard wiring it won't do much/anything. I would assume that a relay will either work or not and since it does work after reset it seems like to issue isn't with the relay. If there is a poor connection and depending on what the controller chip is monitoring I am thinking that it is reacting to the damage to the trace and that is what is causing the error/failure. Again, assuming that the trace is the cause then I am thinking that if I hard wire from the relay post to the power post (exactly what the trace does) then I should be offering a better path for the circuit and it should work. Is this reasonable thought?

[stj]

remove the relay and sand/ file the contact and check the case isnt melted around it.

[Eaglecrest]

I appreciate your advice, but you aren't answering my question. I don't see why I would need to remove the relay. It seems to work fine, when the board works. I would assume that a relay either works or it doesn't. Why would a relay work for a while, then stop and after "resting" work again?

Additionally, I purchased a used replacement board that had the same problems. Close examination of this board showed it had the relay replace and it appears that when the relay was replaced the trace I am asking about direct wiring was damaged and soldered to repair it. So I am guessing that if the trace has an issue it will cause the controller chip to see an error and shut down the system. It seems the best way to test this out would be to run a wire directly from the relay post to the power connector post, which is what the trace in question connects. So the question at hand is if there is any reason to believe this would work or would cause a problem. I don't see why, but am asking for advice from people wiser than me.

Stated another way, if the problem is the trace then I can replace as many relays as I would like and never fix the problem.

[stj]

most likely if you have 2 with burned pads the relay is burning inside and the heat from that is burning the pad.
it needs a better quality ore higher current relay.

[CapLeaker]

Same as: if a relay clicks when energized, doesn’t automatically mean it is good. As far as that black spot on the PCB: take the coating off, unsolder the relay, check these relay by energizing and de-energizing the relay and checking the resistance while doing so. Clean the board resolder the relay if it is good or replace with a new relay, if you aren’t sure. Verify the PCB ais working and go from there.