lack of signal on PIC Ports

Hi,
I designed a board for PIC 16F877A. I put four LED three on PortE and one on PortB.3(with 330 ohm resistor). After programming of PIC I have no signal on that ports and all LED's are off. I tested other ports and they had not signaled, too. Voltages of ports are different. For example porta.0 and porta.1 is near 0 but porta.6 or 7 is near 1v. I have 5v on VCC pins and VPP is set to 5v and two VSS are grounded and my crystal is 20MHz with 33pf capacitors.
Please guide me, why ports have not signaled.

Could be many reasons, how are you initialising the PIC?, and what are your config fuse settings?.

thanks. all are default

Hesam Kamalan said:

thanks. all are default

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But what are those?, and why would you think they are correct?.

there is a lot of combination to find out. you can review this things
1.How about Trisa,b,c,d,e
2.Configuration of pic
3.Look at your Xtal is working or not.
(I'm doubting from this one)