K8048 Reads but won't Write

Hi All

I have a K8048 Velleman programmer which used to work just fine and dandy. Now, when I try to program one of my 16F84A’s using progpic2 it comes up with something like

“Write error at: 0000 Wrote: XXXX Read: 3FFF”

I tried this for 6 (six) different pic’s 4 of which are brand new, yet still the same result. Note that it used to work just fine.

Any ideas?

Thanks

I seem to be having the same problem.

At first my k8048 worked great but then all of a sudden every pic would only program once, now i get the error message above about a write error when i try to program them for the SECOND time.

I have noticed something odd about the board that I think is related. The blinking LED that illuminates in the two “on” switch positions, program and run, blinks very dimly (and slowly) when the main switch is in the MIDDLE position! … but only when there is a PIC inserted in the socket.

Also, there is a voltage on pin 12 at the PIC socket… it seems to be leaking through to VDD somehow? I am confused about this. I was very careful in my assembly, and have since checked it over visually very carefully. I even brought it to work today to have it looked at by a longtime electronics expert, and he isn’t sure why it is the way it is or if it is proper behaviour or not. He suggested I use more voltage than my current wall-wart puts out, which is 18v (when set to “12v”, it’s a variable)

I don’t think the LED used to blink dimly while the switch was in the middle position, and I have always been using the same power supply, so I don’t know, but I will try that.

I can also add that, when the switch is in the MIDDLE position, AND there is a pic inserted, pressing any of the SW1 to SW4 causes the “do not remove pic” LED to flash at full brightness!

Is this behavior correct? Does it suggest a probable cause?

Please, i really need to get my PIC projects back underway and I don’t want to have to create a whole new programmer :frowning:

THank you to the Velleman team who I know are out there :slight_smile:

The leaking voltage via some programming pin’s (12) are not a problem.
The only thing that could happend is that the internal program starts to run, so that’s why some LED’s are blinking.

Voltage must be arround 15V at the input of your K8048’s PCB, 12V is to low because the programming voltage is arround 13V.

Your programmer doesn’t read also because empty space is always 3FFF in a 16F84.

Please check again assembly, power, and…cable !!! must be 9p full connected serial cable and a real RS232 port (not a USB routed).
You can’t get also an ID error because a 16F84 doesn’t have one.

the message i get when trying to write to pic a 2nd time:

Write Error at: 0001

Wrote: 3050
Read: 3010

never mind, i have figured out my problem, the problem is that the user is not very observant.

for some reason writing the first time works, i don’t know if i set the chip type correctly but it was at 16f627 instead of 16f628A like it should have been.

please learn from my lack of observation. it now works properly.

one confounding thing is that the light (LD9, “do not remove pic”) no longer blinks when the switch is in the middle position after programming successfully.

Perhaps programming it with the wrong version number (or trying to anyways) affects a config word of some sort… i don’t know! sorry for wasting space.