[Usbpicprog-technical] Help making one. Getting strange results...

[RedoX <ad...@re...>]

 Hello,

First, I'm a French student, I know my English isn't perfect, but I'll
try to make it look good. I apologize in advance for my mistakes. So:

I've been trying (fighting ? ^^ ) to make a board of the through-hole
version of UsbPicProg for almost a week now, but I'm still having a lot
of problems with it... I got a single side board so, I'm not using the
ground plane on top of the board, but put some jumpers to join grounds
on the bottom plane. Maybe that's the cause of all my problems... Your
opinion on that point ? I don't think that's a problem but am maybe
wrong too :/

I didn't put R13 on the board because, I didn't know what value
choosing, and when I tried wit ha 10k Ohms resistor, the results were
even worse, so I removed it. Am I wrong ?

I'm currently using Archlinux 32bits  with the latest versions
availables at download (r924 for the firmware).
IO Test are showing promising results (10.7v on VPP, the others are OK.)

I've checked and checked again my board, but I've got some weird results:
I have 3 models of PICs: three 12F683, three 16f688 and two 18f2550 (one
is on the board, the other one wasn't working well when I got It :/).

With the 12f683, my board is working well. (Detect, Read, Erase, Check
Blank, Program, .. Everything !)
With the 18f2550, the chip is recognized, can be read, but write on it
is not possible at all (erasing or programming, same result, no
changes.) Voltages are OK in all ways: VPP, VDD, ... And the chip isn't
dead, I'm able to program it with a JDM-like programmer (3-4 resistors,
and a BS170 to get voltage on Vdd, it's not working without it (while
the 12f683 is OK without the mosfet...)) with picprog software.
With the 16f688, even worse... The chip isn't even recognized by the
software. (I've tried different ones, no results)

Oh, when I'm running the IO tests, board connected to a chip, I get this
result: When I set Vpp to float and Vdd to 5v, Vpp goes to 4.7v (as Vdd
really does).

I tried many times, checked every traces, checked almost every single
solder plot, checked all the transistors, ... Tried version 4.0 stable
of the software and firmware. No results in any way.
I've planned to make an other board, cleaner than this one (traces are
not perfect everywhere) but I wish to make this one working if possible
as I don't have to much time at the moment...

Do you have any idea ? Met the same problems maybe ?

First, thank for your project, very interesting.
And Thanks in advance for every little piece of help you may give to me.