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USB PIC Programmer with 40 pin Zip socket

Take the 18F2550 out of the socket.

With the pickit 3 connected to the board, open the software and tick the VDD on box under the Microchip symbol.

Measure the voltage between the VCC pin and GND on the board - it should be very close to 5V.

Then tick the MCLR box and measure the voltage between the MCLR pin and GND on the board, it will be either about 9v or 12V - I forget which it is for the 18F2550.

If those voltages are there then it's a case of following through to the socket to make sure those voltages are on the correct pins for the PIC. 5V should be on pin 20 and MCLR voltage should be on pin 1.
 
Continuity checked as follows:
ICSP pin - PIC pin
/MCLR - 1
V+ - 20
V- (GND) - 8, 19
Clock - 16 ! instead of pin 27
Data - 28

The PGC pin of the adapter board has a direct connection to pin 16 of the PIC!
Also, the PGC pin of the adapter has no connection to any of the jumper pins!
I am stuck.
 
Mostly PIC18F2550

Exactly WHAT micro are you trying to program? You said 18F2550, which is a 28 pin chip, then you said a 40 pin chip.

Details please. I'm sure you just have a configuration problem.
 
Cannot see any resistors for /MCLR ? Does not look like the same board as in the Amazon page ? Check if there is a 10k pull up on MCLR pin ( at least)
 
Last edited:
Finally my order for
has arived yesterday.
I downloaded and installed PICkitminus on Windows 7 and Windows 10.
On both PCs trying to "READ" a PIC18F2550 resulted in a message "No device detected".
Did I buy a "lemon" or am I missing something?
Reviews of the programmer hardware on Amazon are quire discouraging.
I have the same programming kit and I have used the socket several times with different 40-pin microcontrollers and it has not given me any problems.
 
I wish I'd answered this earlier... I have pickits genuine and copies 1, 2 and 3.

I bought a TL866II years back.... does a lot of chip... I mean A LOT of chips
The IDE is easy.. Never whinges about power, just gets on with it. Before you say... yes it doesn't do a lot of the newer chips.. up to K series at least
 
I thoroughly checked the adapter board. There is no connection from pin 27 of the PIC to any accessable pin, jumper, solder joints and copper traces on the board (top and bottom side).
Pin 27 of the PIC corresponds to pin39 on the solder side of the board.
Therefore I think the PIC doesn't get any clock pulses.
What if I broke the copper trace from pin PGC ( 5-pin connector on the board to PICkit 3) to pin 16 (PIC) and made a wire connection to pin 27 (ICSP clock/RB6) of the PIC?
Any new ideas, except returning the device to Amazon?
 
Please have a look at the close-up image of the ICSP connector on the adapter board.
IMG_0773.jpg
 
Closeup pic of the bottom side please.
 
See closeup pic of the bottom side.

Checked:
V+ (PIC pin20) = 4.94 V
/MCLR (PIC pin1) = Adapter board PGC = 0.02 V, i.e. Vp is not supplied from the PICkit 3 device!

Clicking on "Tools" ---> "Download PICkit Operating System"
displays ..\jaka\PICkitminus\PK3OSV022001.hex
Upon selecting and opening the file, the program reports success (see screenshot).

Clicking on "Read" ---> STATUS (red LED) lights up for a short time.

IMG_0774.jpg
OS Download.jpg
 
/MCLR (PIC pin1) = Adapter board PGC = 0.02 V, i.e. Vp is not supplied from the PICkit 3 device!

This is only applied during programming.

Will you post a detailed picture of the entire bottom of the board? I'm trying to trace the connections. I can see that PGD connects to a number of pins, but the pictures I can find online don't clearly show where PGC goes. It's the trace running horizontally just above pin 40. I suspect it goes to the header connections.
 
Question from For The Popcorn:
Will you post a detailed picture of the entire bottom of the board?

Reply:
Please see my posting #37. I can zoom in for just pats of the image.

For me the biggest puzzle is in my posting #50. - I can't think of any possible explanation.
 
mine doesn't find the chip if you don't click the VDD on button
it find the programmer and loads the firmware but will not program it if you don't turn on VDD
 
The /MCLR pin on any PIC needs a pull up to Vdd for programming so wherever the power comes from , the pin should be Vdd ( 5v - 3.3v ) , This is not diagram of PIC18F2550 ICSP .
ICSP.jpg
 
Here is a picture of "the same" board on internet. It shows a connection from PGC to pin 39 as far as I can tell.

Screenshot_20250127_105516_Edge.jpg




And a picture of your board. No connection

Screenshot_20250127_105330_Edge.jpg


Looks like you got a bum board.

I would scratch the soldermask from the PGC trace and solder a jumper to pin 39.
 
Gentlemen,
Thank you all for your support and effort.
I just made conductivity test, the result is (IMO) shocking.
ICSP Pin 3 (GND) on the adapter board has connection to the following pins (with reference to the PIC18F2550 pin-out (no PIC in the socket): 5, 7, 8, , 12, 18, 19, 24 and 26.
I am convinced that the board is faulty, maybe several shorts in the multilayer pcb.
After this I am not surprised about the many negative reviews of the item on Amazon.
I am undesided,whether I should ask for replacement or try to find a different product.
BTW, with the PICkit3 in stand alone mode (adapter not connected) the test
"Tools" ---> "Troubleshoot..." was ok.
 
You could use a bread board and make the 5 connections from the PICkit 3.
 

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