Two suggestions:
1. Contact
the manufacturer for tech support assistance. They may be able to give you the values and ratings for the parts.
2. Do the resistors have color code stripes, or are the values printed on them as digits? In either case, can you read the color stripes or digits?
If color codes, post them, and I or another member can translate them for you.
If digits, are there three or four digits? Three digit codes are used for 5% tolerance and above. The first two digits indicate the value, and the third is a multiplier (the number of zeros following the value digits). For example, 473 would mean 47,000 ohms or 47 KOhms.
Four digit codes are used for 1% tolerance. The first three digits indicate the value, and the fourth is a multiplier. For example, 2432 would mean 24,300 ohms or 24.3 KOhms.
The physical size of the resistors determines the wattage rating. Check any resistor supplier for the ratings of comparably sized parts. If these parts fried because they were under-rated for power handling, and there is room to replace them with slightly larger parts, they may not fail as quickly if you use parts with higher wattage ratings.
Use the same technology or better parts. For example, carbon film, metal film, wire wound, etc.