Control board blows as soon as machine is powered on.

[Mark Flint]

I found the control board to have burnt out components on it. So ordered a new board. Before installing the new one I did some checks:

1) motor windings – fine
2) motor capacitor – fine
3) compressor windings – fine
4) compressor thermal switch – fine
5) turned power on WITHOUT control board – nothing blew the fuse so I presume no fault to earth
6) water pump – took it out and hooked it up to 240v, it worked OK but was only drawing half the rated wattage (drawing 7w instead of 14w)

After doing these test I decided it was safe to install the new board. As soon as I powered it on I heard a cracking sound, and on inspection a component on the new board had exploded. (Shame the control board is not protected by its own fuse.)

The machine is a Grundig heat pump dryer – GTN38250MGCW. Lights come on with the program selection but the machine won’t Start the program. This was the original problem.

Any tips on what other tests/checks I should have done would be much appreciated.

Thanks, Mark

[electrofix]

would need to see what has blown on the board to work it out

Dave

[electrofix]

if the traic has blown something has pulled too much current

look at pic which pin is your triac connected to

Dave

[Mark Flint]

electrofix wrote:if the traic has blown something has pulled too much current

look at pic which pin is your triac connected to

Dave, many thanks for that. According to your pic the triac is connected to the lamp. I will check what’s going on with that. Much appreciated.
Regards, Mark

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