Using MAX7221

[elec_mech]

Hello Ladies & Gents,

I'm attempting to make a countdown timer using eight seven-segment digits controlled by a MAX7221. Upon initial breadboarding I got it to work. However, I decided to change some wiring to have the digit order better agree with the software and it hasn't worked since. At one point I accidently hooked up the current limiting resistor to the MAX7221 to the Vcc line. I've replaced the MAX7221 with a new one. I bought new breadboards and build a new circuit from scratch, also without luck. I'm blinking an LED to indicate when the program starts and stops and that works fine, so the program is running. I've also tried placing LEDs on the data, clock and enable lines to check the I/O pins and they work fine. I noticed in a previous topic that the there may be noise and added 10uF and 0.1uF capacitors - still no luck. I've included the code and a schematic of what I've build.

PORTA = $00		' Set all port a pins low
PORTC = $00		' Set all port c pins low
define OSC 4 	' Tell the program the oscillator is running at 4 MHz
	TRISA = %11111111		' Make all port A pins inputs
	TRISC = %11100000		' Make port C pins 4 & 5 inputs and the rest outputs
	PORTA = $00				' Set all port a pins to low
	PORTC = $00				' Set all port c pins to low
	CMCON.0 = 1				' Turn off comparator module
	CMCON.1 = 1				' Turn off comparator module
	CMCON.2 = 1				' Turn off comparator module
	ADCON0.6 = 0			' Use VDD as analog reference
	ANSEL = %00001000		' Use AN3 as analog input and set all other analog 
							' inputs to digital pins

	CS_Max	             VAR	PORTC.3		' Chip select for MAX7221 IC
	CS_DS	             VAR	PORTC.2		' Chip select for DS1302 IC
	SPI_CLK	             VAR	PORTC.0		' Clock for SPI communication
	SPI_SDO	             VAR	PORTC.1		' Serial Data Out for SPI communication
	Tog_Switch	VAR	PORTA.1		' Toggle switch
	Sel_Switch	VAR	PORTA.2		' Select switch
	
	b1		VAR	byte		' Button variable for toggle switch
	b2		VAR	byte		' Button variable for select switch

'***********************************************************************************************
	HIGH CS_Max
	pause 500					' Wait for 500ms

Main:

	HIGH PORTC.4
	PAUSE 500
	LOW PORTC.4
	PAUSE 500

	LOW CS_Max					' Enable the MAX7221 to receive data
	SHIFTOUT SPI_SDO, SPI_CLK, 1, [$0F01\16]		' Turn on Display Test (light up all LEDs on all eight digits)
	HIGH CS_Max				             ' Pull chip select to MAX7221 high to act on transmitted data

	PAUSE 5000				             ' Wait one second

	LOW CS_Max				             ' Enable the MAX7221 to receive data
	SHIFTOUT SPI_SDO, SPI_CLK, 1, [$0F00\16]		' Turn off Display Test 
	HIGH CS_Max					' Pull chip select to MAX7221 high to act on transmitted data

	PAUSE 1000					' Wait one second	

	HIGH PORTC.4
	PAUSE 500					' Wait one second
	LOW PORTC.4
	PAUSE 500
END							' End Program

I do not have the DS1302, buttons or photoresistor connected yet as I'm stuck trying to get the MAX7221 to work. Outside of ESD problems or gremlins, I'm stuck. Any advice is greatly appreciated.