I Bought a Inspiron 4000 on Ebay. Seller said that it would not boot. He said Dell told him in was probably the motherboard so I bought it. Replaced the motherboard with a 002UH use the same cpu (P3 850 SL4AH) came with the Inspiron.The new motherboard would not boot. Bought a new CPU P3 850 SL53L. The screen came up and said Processor Start Failure The revision of motherboard does not support the processor installed. Would like any help I can get. Would like to know all the CPU's that will work with this board. Dell told me they do not have a replacement CPU.