Mysterious Reset

[skimask]

Hello,
I have a 1000uF cap decoupling the chip, with a 10K pulling MCLR high. My powersupply is from Mouser: 5V, 5A part# 552-PSA-25LS-050-R.

I will be plugging in the 'F88 tomorrow, and that might solve the issue... but still! What's going on?

Thanks for your help!
I've gotten much out of searching the forums for the past few months!

-Joel

You might have a 1000uF, nice fat cap across the rails, and they might even be right at the PIC, but...do you have a small cap with low ESR right there also? Generally speaking, a 1000uF cap is more for power smoothing, not decoupling. The problem might be that the big ol' fat cap can't do it's job at high freq's because of high ESR...in other words, works at low freq's, not at high freq's. I'd (as well as others I'm sure) suggest putting a .1uf right at the PIC's power/ground pins, both sides (if you're using that sort of PIC, 40 pin types). I'd doubt if an 'F88 will solve your problem.
Also, you're driving relays. You might have enough juice coming out of your power supply to drive everything...steady state. But what about the instant that a relay closes? If your power supply can't handle the instantaneous load (which could very well be far above the steady state load), you get voltage drop (which the 1000uF should help with), and instant reset

And don't forget about putting a 'dump diode' across the relay coils. Without one, a relay can really screw with a power supply in unintended ways.
Let us know what happens...