bizarre problem 16f628-20/P -?

[phoenix_1]

Well, again, let's see some code, some configuration information, what kind of programmer, software, maybe some schematic information, power supply, anything, etc.

@ DEVICE pic16F628, HS_OSC
' ---- High Speed Oscilator
@ DEVICE pic16F628, WDT_OFF
' ---- Watchdog Timer=OFF
@ DEVICE pic16F628, BOD_ON
' ---- Brown-Out Detect
@ DEVICE pic16F628, LVP_OFF
' ---- Low-Voltage Programming=OFF
@ DEVICE pic16F628, MCLR_ON
' ---- Reset Pin=Internal
@ DEVICE pic16F628, PWRT_ON
' ---- Power-On Timer=Disabled
@ DEVICE pic16F628, CPD_OFF
' Data Memory Code Protect
' Set to CPD_OFF for Development Copy
@ DEVICE pic16F628, PROTECT_OFF
' Program Code Protection 

'MCLR pin is pullup at 5V via 4K7 
'external XTAL @20MHz and two cap (I was probe from 10pF to 27pF)
'portb.1 to led via 330 ohm and 330 ohm to GND (led is low current green)
'when I put in same socket PIC 16F628-04/P and change XTAL to 4MHz and 2x27p LED
'blinky OK and if I change in that socket 16F84A-20/P and use XTAL 20MHz and 2x27p
'it blinky 100% OK. THAT MEAN THAT PROTO PCB is OK ........
'these code is for 16F628-20/P @20MHz HS osc
'programmer is EPIC programer and work fine for me ;-)

define osc 20
CMCON = 7          ' PortA = digital I/O
VRCON = 0          ' Disable A/D Voltage reference

low portb.1
pause 250

loop:
high portb.1
pause 1000
low portb.1
pause 1000
goto loop
end

[paul borgmeier]

Something to try ....
remove (carefully unsolder?) the LED and see if pin goes high low high with a meter. If this works then reconnect up your LED and add decoupler Cap close to Vdd (10uF or similar).

[phoenix_1]

Something to try ....
remove (carefully unsolder?) the LED and see if pin goes high low high with a meter. If this works then reconnect up your LED and add decoupler Cap close to Vdd (10uF or similar).

Thank's friend,
I was probe many trick's nothing want to work,simply I am confused....
Is some posibility to someone manufacture clone of PicMicro or something same ???
On first look it same signature like other on other PicMicro what I have in colection..
It is not important to me to I make it work and sale in some my hardware but it very interest for me to I find what is it why...etc.
I was probe to config it with internal osc at 4MHz and same problem too.
Now I go to get frquency meter and I will post if is osc activity on it ?!

[Archangel]

Thank's friend,
I was probe many trick's nothing want to work,simply I am confused....
Is some posibility to someone manufacture clone of PicMicro or something same ???
On first look it same signature like other on other PicMicro what I have in colection..
It is not important to me to I make it work and sale in some my hardware but it very interest for me to I find what is it why...etc.
I was probe to config it with internal osc at 4MHz and same problem too.
Now I go to get frquency meter and I will post if is osc activity on it ?!

Hi Phoenix,
I am having a little trouble with the use of the word "probe" As I understand this word, it is when you put the "test probe" of your meter on a voltage source or when your doctor pokes you looking for a tender spot, if you would please elaborate a little you would be helpful.
As to your code: Verify it is a 16F628 and not a 16F628A correct?
Now,

CMCON = 7          ' PortA = digital I/O

incorrect, cmcon = 7 ' turn off analog comparators

'when I put in same socket PIC 16F628-04/P and change XTAL to 4MHz and 2x27p LED
'blinky OK and if I change in that socket 16F84A-20/P and use XTAL 20MHz and 2x27p
'<font color=red>it blinky 100% OK. THAT MEAN THAT PROTO PCB is OK ........</font color>
'these code is for 16F628-20/P @20MHz HS osc

Proto boards are loss-ey, which is to say, using them is much like installing a bunch of unwanted capacitors, the connections are often poor. If you are using crystals instead of resonators, you might try reducing/not increasing the value as you go up in frequency, even try it without the caps (on the breadboard only), as I said before, the breadboard adds a bunch of extra capacitance to the circuit. Yes it is possible you got a hold of a counterfeit
PIC, although somewhat unlikely. Keep your wiring to the crystal very, very short. Anything attached to the crystal ports will load down the oscillator and keep it from working.