My DK Jr pcb is missing blue. Verified its the pcb. Hoping it's something simple like a prom. I have a working DK and DK3 pcb if I can swap proms to test. Any ideas are appreciated.
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My DK Jr pcb is missing blue. Verified its the pcb. Hoping it's something simple like a prom. I have a working DK and DK3 pcb if I can swap proms to test. Any ideas are appreciated.
Prom 2E is used for both blue and green so if your green is all good then it's prob not that. Could be the final transistor that drives blue out to the monitor. (Q11 on the CU PCB)
Did a quick reading. I'm getting .2 on one side of the transistor and .5 on the other. Checked q11 on DK and her .5 on both sides. I recall .4 to .6 is in range for most transistors. Would that reading indicate it's bad or is the tolerance higher?
I'd still swap the color PROM with a known good one.
ICs don't fail completely (always). One output might be bad, IMHO.
Easy test to be sure.