i have recently bought and completed the k8048 board and upon attempting to program the PIC16F627 which came with the board, i discovered that the 18p slot is not working.
i tested each socket with my multimeter and i got a reading on all sockets except for the 18p. i have checked all my connections i have made and am at a complete loss as to what is going wrong.
i am using the self made cable, and a 12v 500mA unregulated power supply and the PIC16F627.
Hi,
What pins against what pins did you measure exactly?
*While the switch is in the “run” position then and no cable connected, using pin 5 as “ground” you should at least measure the following to start with:
–>pin 14: +5V (Vdd)
–>pin 4: +5V (not MCLR)
*While the switch is in the “Prog.” position asn no cable connected you should at least mesure
–>pin4: +13V
–>The led LD8 should be on.
If you are trying to use the 18 pins device then make sure (to start with) that JP3 and JP4 are in place.
upon reading your reply i have re tested my k8048 and have found that the combinations you specified have the following results:
-pin 14 to 5: no reading
-pin 4 to 5: building up to 1 v then starts from 0 and builds up again.
also i have noticed that the LD8 does not light ever. i did have some suspiscion about this led and i there fore tried turning it round to find no success.
any other ideas??
also could you tell me if the D6 diode is supposed to be attatched to the T5 transistor? i have a feeling which is that these twon components are wrongly attatched and are causing all this trouble.
[quote=“johnsy2004”]-pin 14 to 5: no reading
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Are you sure that the switch is in the “run” position?
If it is, then please first check if LD7 is “on” (it is always on as soon power is applied to the board).
If LD7 is on, then the supply of the board is Ok.
In this case check the copper tracks from VR2 to the switch and from the switch to LD9 for interruptions.
If LD7 is not on, then please check the power circuit on the board:
D1 (check polarity)
C1 (check polarity)
VR1 (check mounting and type – 78L12 --)
D1 and D2 (check polarity)
VR2 (check mounting and type – 78L05 --)
[quote=“johnsy2004”]also i have noticed that the LD8 does not light ever. i did have some suspiscion about this led and i there fore tried turning it round to find no success.
[/quote]
Make sure it is mounted correctly otherwise it will most probably be distroyed one you have the circuit fixed.
[quote=“johnsy2004”]also could you tell me if the D6 diode is supposed to be attatched to the T5 transistor? i have a feeling which is that these twon components are wrongly attatched and are causing all this trouble.
[/quote]
As far as i can see on the circuit diagram D6 is connected to T5 via their “ground” connection (k of D6 and e of T5 are both connected to ground). There is no other connection between the two.
oh sorry i thought pin 14 to 5 was for program mode. i will check later and edit with results.
as for the power led, it is always on. i will swap the ‘read/write’ led for a new one and place it in reverse to see if that helps. although i have tryed it that way before and it had no success.
ok thanks. i did the test with the same outcome although i may have discovered the problem.
i think that from an accident upon finishing the board i put the microcontroller into the board and it did not go in straight. i then pulled it out to re insert it and i caught the socket from the underneath and managed to pull one side out THROUGH the solder :? it is a little late to re-solder right now so i will solder it again tomorrow.
do you think this may have been the problem?
and i have no idea how i am going to manage to solder 18 places at the same time :lol:
This is a very good sign. It means both the 13V and the 5V supplies are Ok.
Next step is to make LD9 blink in both “RUN” and “PROG.” modes. So, please check the copper tracks from VR2 to the switch and from the switch to LD9 for interruptions.
Do not insert any PIC’s yet before this is OK.
[quote=“johnsy2004”]ok thanks. i did the test with the same outcome although i may have discovered the problem.
i think that from an accident upon finishing the board i put the microcontroller into the board and it did not go in straight. i then pulled it out to re insert it and i caught the socket from the underneath and managed to pull one side out THROUGH the solder :? it is a little late to re-solder right now so i will solder it again tomorrow.
do you think this may have been the problem?
[/quote]
It could be that a copper track to/from the switch is interrupted due to the accident.
[quote=“johnsy2004”]and i have no idea how i am going to manage to solder 18 places at the same time :lol:
[/quote]
I think the only sensible thing to do is make all socket holes free using “desoldering” wick (“desolder” long enough), remove carefully the socket, check all copper tracks in the neighbourhood and solder in a new socket.