simonp wrote:Hmm, how ironic is this? I just went to roast some beans and the Hottop is totally dead.... Something had failed on the main board and no supply is getting to the control board! Not impressed that the new boards have failed after about 10 roasts. Unfortunately the extra board for the computer control need the original control board to be still working so now I am a bit stuffed. To add even more irony, the second pair of upgrade boards (sent in error) have just gone back to Taiwan....
simonp wrote:It seems the PCB mounted fuse prior to the bridge rectifier has gone, so no supply to the low voltage stuff. I can't see anything wrong with the supply after that so perhaps we just had a voltage surge though fuses usually go for a reason. My internet router did throw a wobbler at a similar time to plugging in the Hottop so could be a mains issue. I'll just have to get another one and see, you have to buy them from Farnell in packs of 10 of course
As I've had to half strip the machine I might as well do the thermocouples whilst the thing is in pieces, though I now have the problem of a rather low coffee supply and no roaster
Oh what a pain, it must be very frustrating.
I am sure that Shelly at Hottop will sort it out for you if you contact her. I assume from what you say that the roaster is completely dead with no sign of life from any LED's on the power board.
The power board supplies a 5 volt supply to the rear fan, bean cooling fan and the bean stirrer motor as well as the control panel. I have only heard of one other user having similar problems and in his case the bean cooling fan had failed and shorted out which caused failure of the 5 V power supply (I think the voltage regulator failed). I suggest you test the fans and stirrer motor to ensure they have not failed/shorted and/or disconnect them before trying the repaired board.
simonp wrote:...The silicone is rated to 220 so add you say will need an eye keeping on. I plan for it to only just come through so hopefully it will be OK.
I am almost certain that it will be fine. The rating of 220 C will be for continuous service and it will only ever see temperatures slightly above that for very short periods of time.