P16PRO - troubleshooting

[whiz115]

You can try to downloud this little program, https://www.geekhideout.com/parmon.shtml It let's you test your paralell port you can toggle every pin and see if they go Hi/Low.

my port is ok... tested it with an old dot matrix printer but thank you very much!!

 

[OY2L]

I dont know if this can help you, but at this link is a long thread of my problem when i first built my p16pro40 programmer, finaly i found out the problem was my laptop LPT port even it was working perfect with my printer.https://www.electro-tech-online.com/threads/winpicprog-and-p16pro40.30857/ But p16pro40 is a very good programmer together with Nigel's WinPicProg.

 

[kchriste]

BTW, the main point- why keeping higher differential is still an issue.

whiz115 said that the 78L05 was getting hot with only 12V input. The programmer needs at least 16.1Vdc input to generate 13V for Vpp. With 16.1V input you'll lose 1.4V in the bridge rectifier which leaves only 1.7V across the 78L08 which is bootstrapped by the 78L05 to provide 13V for Vpp. The datasheet specs the typical dropout voltage of the 78L08 as 1.7V @ 25C.

Finally it is also possible that 78L05 might be a defective piece.

Yes, that is possible. It's also possible that it is installed backwards. It would help if whiz115 could post a clearer photo of both the top and bottom of the PCB. it would also help if he posted the voltages measured on the outputs of both the 78Lxx's.

 

[whiz115]

Yes, that is possible. It's also possible that it is installed backwards. It would help if whiz115 could post a clearer photo of both the top and bottom of the PCB. it would also help if he posted the voltages measured on the outputs of both the 78Lxx's.

everything looks correctly installed...

with input voltage 16.90V

78L05 output 5.27V
78L08 output 13.34V

hmmm i found on my desk a DM74S05N might be the solution?!

kchriste have you understood the circuit? you asked me why it has 6 pins connected...
have you found any errors? also can you explain the leds for the specific circuit
and not for the one on the picallw site?

thanx

btw sorry guys... I already know from the very first time i started to play with pics that they require 13V for programming, so how on earth i was expecting 13V from 6VDC power supply?
well... this text got me confused:

So here are only a few words about hardware. Supply voltage can be either AC or DC. Voltage Vdd must be between 4.5 and 5.5 V. For this purpose integrated stabiliser 78L05 (Vdd=5V) is used. It has current limitation (protection) 100 mA and with this feature protects inserted PIC from damage in case something is wrong connected. Programming voltage 13V is provided with 78L08, which has pin 2 connected to Vdd (not to the ground) and on his output there is a voltage 5+8=13V"

 

[kchriste]

with input voltage 16.90V
78L05 output 5.27V
78L08 output 13.34V

That looks good to me. It shouldn't change much when you install the 74LS05, 7405, 7406, 74LS06, etc. If it does, then the 74xxxx is bad or inserted wrong. The 78L05 will get a little warm. This is normal. It should not get HOT and go into thermal limiting.

hmmm i found on my desk a DM74S05N might be the solution?!

You could try it. The 74S version tends to draw more current than the 74LS version. It also requires more drive current from the parallel port. At this point I would install a socket for the 74S05 so you can try different types without reworking the PCB too much.

kchriste have you understood the circuit? you asked me why it has 6 pins connected...
have you found any errors?

The circuit is a copy of the first PIC programmer I built when starting with PICs about 5 years ago:
https://www.electro-tech-online.com/custompdfs/2008/08/p16pro40.pdf
I used 74LS06's instead of 74LS05's. I also had to add C4 (330pf) for mine to work reliably. The circuit works if you have a legacy parallel port on your computer. It won't work with a USB-->parallel adapter. I don't remember asking about "6 pins".

also can you explain the leds for the specific circuit and not for the one on the picallw site?

If you mean for this one:
**broken link removed**
then the green LED is on when the programmer is idle and power is applied. It goes out when programming and either one of the RED ones come on to indicate that Vpp has been applied to PIC.

 

[whiz115]

At this point I would install a socket for the 74S05 so you can try different types without reworking the PCB too much.

if i had one...believe me i wouldn't get into trouble soldering and desoldering.

thanx again.. i'll let you know when i have any updates..

thanx the other guys too

Nigel don't get angry with the new generation! blame Mcdonald's and Applebee's

 

[mvs sarma]

why not replace the chip with 74LS series if not 74HC series instead of plain.
DM7405W may consume more from 05. thus you may use a plain 7805 regulator. but the input and output pins are just reverse, as you know. IT CAN STILL BE MOUNTED

 

[whiz115]

why not replace the chip with 74LS series if not 74HC series instead of plain.
DM7405W may consume more from 05. thus you may use a plain 7805 regulator. but the input and output pins are just reverse, as you know. IT CAN STILL BE MOUNTED

i'll see what i can find... in case DM74S05N is not suitable.

 

[Nigel Goodwin]

Nigel don't get angry with the new generation! blame Mcdonald's and Applebee's

What's "Applebee's" ?.

I obviously know McDonald's, purveyors of overpriced crap food for little kids!

 

[mvs sarma]

What's "Applebee's" ?.

I obviously know McDonald's, purveyors of overpriced crap food for little kids!

The O P clearly mentions, as I understand, that even if he has a chip, he would not take the trouble of de-soldering and re-soldering.

Hence we may feel that this post is perhaps, closed, as it serves no more purpose, Nigel.

 

[whiz115]

What's "Applebee's" ?.

I obviously know McDonald's, purveyors of overpriced crap food for little kids!

it's similar...

https://en.wikipedia.org/wiki/Applebees

i've been 3-4 times and it's full of kids too!

P.S some foods are great i can say....

The O P clearly mentions, as I understand, that even if he has a chip, he would not take the trouble of de-soldering and re-soldering.

Hence we may feel that this post is perhaps, closed, as it serves no more purpose, Nigel.

i was referring to the IC socket... kchriste asked why i don't use one...

i'll return on this subject as soon as i have updates... right now i left it
aside until i go and get some components....