If you increase the value of R175 slightly, it should decrease heating of the transistors but before you do that, check the connections between Q124 and Q125. They are in parallel and should heat about the same.
Installing 124 and 125 with longer lead length so they are closer to the fan they will last longer.
The resistor C191 has to be in the circuit for the circuit to work.
Installing 124 and 125 with longer lead length so they are closer to the fan they will last longer.
The resistor C191 has to be in the circuit for the circuit to work.
Q124 and q125 are in parallel. Checked.
Made a little drawing for the connections resistor c191.. Because this resistor burns quickly. It seems, it's a voltage divider between q118, q116 and q113. All connected with collectors.. Normally it shouldn't burn.. Can you supply me with a diagram of this board? I would check all components, if they are correct.
Made a little drawing for the connections resistor c191.. Because this resistor burns quickly. It seems, it's a voltage divider between q118, q116 and q113. All connected with collectors.. Normally it shouldn't burn.. Can you supply me with a diagram of this board? I would check all components, if they are correct.
Attachments
Thanks, in Place R172 R173 should be according diagram 560Ohm inside. I have 10kOhm.. Maybe there are other differences? Otherwise everything on this card should be ok.. Then i have to look at the mainboard for the problem
The Resistor is still Burning, No fets in circuit. No shorts between the solder pads from the fets.
Desolder them on the end that's not connected to the 220 ohm resistor. Does the resistor still burn?
Yes, there is no other option... There is no connection where current should flow... The epoxy must be conductive...
But the board is intact. No burnings....
But the board is intact. No burnings....
Resolder the resistors to the transistors (that you just desoldered). Lift the other end of those resistors and the end of the 220 that connects to them and solder them together in the air (not through the board). Does the resistor burn?
It works... The current draw is 1 Amp less... But after 10 seconds, its start smoking from another resistor... But allready better. How to work with this conductive board? Find the conductive place and resolder the parts in air?
You can cut away the conductive parts but making the connections off of the board is an option (albeit not great looking, but neither does hacking the board).
What other resistor is burning?
What other resistor is burning?
Does the voltage across R184 increase as R190 starts to burn?
If you remove Q124 and Q125, does R190 burn?
If you remove Q124 and Q125, does R190 burn?