K8076´1 Red led lights all time

Kits Microcontroller Programmer - Experimenting Project
1

Hi

Go this 8076´1 pic programmer. build. The LD4 led keeps lightning red all time… what could the reson be…wich componets could be damaged.

2

hi,
it could be a simple short circuit, check the soldering on the PCB.
(note: take the microchip out, just in case!)

I hope I have helped,
fish

3

Hi,

After a look to the circuit diagram of the K8076:

If LD4 stays on all the time (with no serial cable connected to the board), then there is something wrong around T1 or T2.

  • First check of both transistors are of the correct type (are they not interchanged?)

  • Then check for short circuits near R5, R6, R8, R8 and D4 (including their PCB connections of course).

  • Then replace T1 and T2.

4

Hello, if my red light stay on with the serial cable but not without, you know what is the cause ?

Thanks

bye