Burned board: has the board failed?

[@Spector_NS5_RD]

I have a pile of boards that i keep from warranty replacements and changeouts. As long as the microcontroller is in good condition (firmware uncorrupted, no broken leads) I can usually fix them with the help of Digikey and/or Mouser. As for burn spots on the pcb's, you're correct that 90% of the time it's power resistors trying dissipate heat. It all has to do with PCB layout, design and thermal considerations. Some PCB manufacturers fair better than others. Thanks for the video!

[@coldfinger459sub0]

Digakey and Mauser and Jamco is like Santa Claus dropping off presents at my house kids candy store. Board failures relays burning excess of resistance relays arcing together well them self shot. Like you say as long as the micro electronics are in good condition easily and cheaply repaired. And you can upgrade them with heavier duty relays that have diode‘s and resistors across the load to get rid of the arcing across the contact points so they don’t wear out. Especially on those systems were somebody way over sized it and it’s constantly short cycling adding tens of thousands of opening and closing cycles across those little contact points.

[@bigdaddydons6241]

Im so happy I found this channel, this might of just saved my career

[@grayfurnaceman]

Glad I could help. GFM

[@lcampm2]

Had a new outdoor unit installed and that came with a year free service. They came and showed me the Coleman/York indoor board with the heat marks on it and said it needed replaced. Furnace is working fine. The wanted $860 to replace it. I was a HVAC building maintenance person for 36 years and I laughed at that. They said things cost a lot here in the valley!! I said the board is no more than $100 and you want how much??? Not interested. Thanks for the video

[@grayfurnaceman]

Good one. GFM

[@timrob0420]

Grayfurnaceman is the real OG.

[@loumonte658]

Good info to remember.

[@mrkrasker9609]

Bakelite circuit boards are prone to darkening from exposure to heat. You get the same effect on epoxy resin boards as well.

[@HN-bn6vv]

Thank you. This video answers my question

[@melplishka5978]

The boards where the resistors are not burnt are the ones used for auxiliary options like electric filters and such. So they were almost never used.

[@ScottDLR]

In aviation, a PCB isn't considered bad unless the fabric of the board is showing. Those white or light green color boards are especially bad at showing heat but as you suggested, it doesn't mean it's bad.

[@coldfinger459sub0]

Your videos are a wealth of experience of knowledge as always thank you for passing down your knowledge to all the new Techs

[@grayfurnaceman]

Welcome GFM

[@I88-4-88I]

GLORY BE ! 😎

[@hullinstruments]

I’d love to buy all those!

[@hullinstruments]

I’d buy all the boards and modules you have.

[@deletesoon70]

Hello, would the blower fan's air movement not be enough to cool the board as it works? Would separate mechanical cooling of the board help keep it cool?

[@grayfurnaceman]

Board mounted resistors are designed to dissipate a specific amount of heat. This does not mean they run cool. They can be quite hot and still perform their work. The point of this video is to get across that a burned spot on the board does not mean there is a failure in the board. GFM

[@oscarc126]

Do you do work on these boards for other people?

[@grayfurnaceman]

No. GFM

[@TheGhettoLobster]

Wow. Never seen a board like that from the York heatpump. That must be ancient

[@grayfurnaceman]

It was a Champion model first sold around 1980 and had one of the first demand defrost systems that worked quite well. GFM

[@johnvitz310]

A million years,,pay attention boy😂😂😂😂

[@caru3257]

Most boards I have replaced are burned at the fan relay.

[@victorgalicia6607]

Ever try soldering something on one of those to repair it?

[@grayfurnaceman]

Yes, if the solder is melted and haloed at the board, I would solder the terminal. I also would solder over traces for the inducer or fan motor if they were burned thru. GFM

[@daveliedholm2296]

Never judge a board by its color.

[@zillacutz]

Hank?

[@tonym6920]

You think that if that’s a common issue, they would insulate the resisters a lot better!

[@mrkrasker9609]

If the resistor was insulated that would cause it to burn up, you want a resistor to dissipate the heat. The fix would be to use a larger wattage resistor. Using a larger wattage resistor would cost more money and eat into the bottom line.

[@jkbrown5496]

@@mrkrasker9609 They won't even spend the money to install them standing off the board to dissipate the heat. Much less install a heat sink.