Sundown SAE-1000D

[Formas]

Does anyone has any info on an Audio Driver board for this Sundown SAE-1000D amplifier. Need identification for U1, U2 and U3 IC's.
please if they could be identified with the board legend so i dont get them misplaced as they are all 8pin dip packages, also the driver board number is DWN0608FV-V20

 

[Perry Babin]

U1 varies but the photos I have show an LM293.

U2 should be a TL072.

U3 is an LM211/311

 

[Formas]

Can u give me the part number for Q5, Q6, Q9, Q12, Q14 and Q18 for the same amp audio Driver board?

 

[Perry Babin]

See if you can get them from the attached image and this link:
Marking smd

 

[Formas]

I’m having a difficult time to decide which part number on the SMD Manual chart on Q6 and Q12 part numbers (DKQ7) and (AGQA).
Is there a standard thru hole part equivalent or name?

 

[Perry Babin]

Transistor marked DK - 2sc4672
Transistor marked AG - 2sa1797

 

[Formas]

Ive rebuilt the driver board (replaced DK, AG, 1D, 2D U1,2,3) all diodes check ok im still getting the mosfets heating up rapidly, ive checked all regulators and voltages +/-5, +/-15 and +/-12v are present.
On mainboard, output circuits and power supply circuits are ok. How do i know if my IC's are functioning on my driverboard or what else is my problem?

 

[Perry Babin]

What is the DC voltage from collector to collector for each vertical pair of drivers?

 

[Formas]

They are 12v each (i had my probe accidently shorted the base and collector of Q9 when doing that test, but i pulled the board and tested and reseat it and i didnt see any further complications or damages).

** I personally didnt change the U1,2,3 IC's there was a tech before me that changes those after i get the part identification from you. The owner brings it to me and ive ordered the transistors and replace those.

 

[Perry Babin]

The TL072 and the LM211 are the only ICs in the signal path but they rarely cause an overheating issue. Are you getting a clean signal to the gates of the FETs?

What is the rail-rail oscillation frequency?

 

[Formas]

With the card in the fets heat up (rising and rapid) the moment its on. I pulled the gate gate resistors thats the only way i can conduct some tests to an extent. With my reference on centertap ground (sec) im seeing 60v on the gate circuit is that normal?

 

[Perry Babin]

Both drive signals have an amplitude starting at the rail and going toward ground. The 9640s are driven from the positive rail. The 640s are driven from the negative rail.

 

[Formas]

How can i make the rail to rail test if the mosfet is heating up immediately as its turned on.

 

[Perry Babin]

Do the signals on the gates look as described in post #12?

 

[Perry Babin]

See also #14.

Does your amp look like the amp here:
sundown audio SAz-1000D

 

[Formas]

See also #14.

Does your amp look like the amp here:
sundown audio SAz-1000D

Yes it does.

Do i check the rail to rail oscillation with or without the card or with or without the gate resistors connected (mosfets in place 1 per bank)? with resistors in place and driver card installed, the fets heats very rapidly.

 

[Perry Babin]

If it's drawing excessive current, you may not be able to check rail-rail. With no outputs or no rectifiers, you should be able to see the drive on the gate pads for the outputs with no excessive current draw.

 

[Formas]

Ive connected back the gate resistors and remove the outputs, with my reference on center tap secondary all i see on the gate pads is voltages -52v and 60v, on my scope (10usT/D 2V/D) is just flat line (all settings). the card is inplace.

 

[Perry Babin]

Solder a 10k resisto between pins 1 and 2 of the TL072 and re-check.

 

[Formas]

There’s no change with that.