help identifying a part for kicker sx1250.1

[buster shanks]

I have a kicker sx1250.1 amp with some shorted components. they are Q51 and Q52 on the power suply end, in the center of the board not on the heat sinks. I guess they are flat transistors and labeling looks like this:


K
D 1691
Y .527


Any recomendations on replacements would be apprieciated.

 

[sweetperfume]

I have a kicker sx1250.1 amp with some shorted components. they are Q51 and Q52 on the power suply end, in the center of the board not on the heat sinks. I guess they are flat transistors and labeling looks like this:


K
D 1691
Y .527


Any recomendations on replacements would be apprieciated.

if tube package replace it with c4793 or c2073 and if bulk then with BD139 or mje340