RD AUDIO D9

[mike49504]

Im repairing this amp it has blown outputs and a blown power supply.

When i removed the spring clamps I noticed there are 2 differnt outputs in this amp. They are FDA24N40F and FQA28N15.

Does anyone know if this amp uses both thoose outputs or does it just use The FDA24N40D'S

[Perry Babin]

I would think that the rail to rail voltage would be greater than the 150v that the 28N15s could withstand.

[mike49504]

Thats what i was thinking . The outputs are all blown . WOndering if i should just order all new FDA24N40F's for this amp ?

RD stopped making this amp and the company switched owners and they told me they had no info on this amp.

[Perry Babin]

Do the solder connections on the FDA transistors look original?

[mike49504]

some kinda do some dont. I know 1 of the part numbers doesnt belong .

On 1 side of the amp i have 6 FQA28n15's that the solder is not orginal on them and 2 FDA20n40f's

On the other side of the amp i have 4 28n15's and 4 20n40f's

[Perry Babin]

What's the voltage rating on the rail caps?

[mike49504]

160 volt caps

[Perry Babin]

I think someone used the wrong parts. If some of the FDA24N40Fs have the original solder, that's what I'd use for all of the outputs.

[mike49504]

Ok well i guess ill pull the board out of the sink and see if i can tell from the bottom of the board.

[mike49504]

Ok the FDA20N40F's are the orginal outputs the solder on them is orginal The FQA28N15'S have been put in at some point and the solder job is bad .

So i have to order all new power supply fets,new outputs,new driver ic's new gate resistors, New drivers for the power supply fets.

Is there anything else i should check for that goes bad when this type of work is done on and amp (wrong outputs)