SinusLive SL-A1500 help needed.

[kimschips]

Hey all.

I have a SinusLive SL-A1500 car amplifier

Error: The amplifier won´t start up.

Have any of you experience with repairing this amplifier before?

Best regards

Kim

 

[Perry Babin]

Is the amp completely dead or going into protect? If it's completely dead, post the DC voltages on the driver IC (TL494?).

IC#
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:

 

[kimschips]

SinusLive

Hello

Thank you for your time🙂

The amplifier draws a lot off current and the red led protected lights

Do you have any idea where to measure in the amplifier?

Best regards

Kim

 

[Perry Babin]

Did you check all of the output transistors to determine if any had failed?

 

[kimschips]

Sinuslive repair

Did you check all of the output transistors to determine if any had failed?

Hello

Now I have measured a bit in the amplifier again.

Transistor Q8 has a short circuit.

How many transistors in the ampifier do you recommend to be replaced?

All transistors Q1,2,3,4 and Q5,6,7,8?

Thanks for all for now

Best regards

 

[Perry Babin]

Yes, you need to replace all 8 of the outputs. Since you only found one shorted, reinstall the others, clamp all of the transistors down (you'll have to place the blown one under the clamp so you can clamp the adjacent output down tightly) and power up the amp. Does it power up and produce audio (at low power output)?

Use a 15 amp fuse in the B+ line to protect the amplifier in case there is another problem.

 

[kimschips]

Hello Perry🙂

I have now replaced all the output transistors with 8 new. (IRF640)

The amp is still in protected mode.

I can measure 53V across the output transistors

Please help again🙂
Kim

 

[Perry Babin]

Does the amp produce any DC voltage across the speaker terminals as it powers up (or after it's power up for a few seconds)?

 

[kimschips]

Yes there is about 10V DC at the output, "constant"

What to look for then?

Thanks
🙂

 

[kimschips]

Hello again🙂

The output varies between 0 and -10V

Have measured -46V at D17 katode here is suppose to be -12V

The katode voltage off D16 varies between +32 and -12V

Help me here?

 

[Perry Babin]

Have you checked all of the driver transistors and the gate resistors for the outputs? Those commonly fail when the outputs fail.

Do you have an oscilloscope?

 

[kimschips]

Have you checked all of the driver transistors and the gate resistors for the outputs? Those commonly fail when the outputs fail.

Do you have an oscilloscope?

Yes I have🙂

I have messured alot off DC voltage around U8-9 D16-D17 it´s looking fine now. Output has zero DC and I can load the amplifier (100W@4ohm for now)

BUT

The Power led in the amp will still not light up

Do you have any ideas for "protection voltage or ref voltage" for the protection circuit I can measure or am I still missing something here??

Best regards
Kim

 

[Perry Babin]

Does it produce rail voltage?

If not, post the DC voltage on the TL494 (594) power supply IC.

IC#
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:

 

[kimschips]

Does it produce rail voltage?

If not, post the DC voltage on the TL494 (594) power supply IC.

IC#
Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:
Pin 15:
Pin 16:

The rail (psu) voltage is +- 62V

I that what you mean?

Kim

 

[Perry Babin]

Yes.

When I get back in the shop tonight, I'll see if I can determine what's causing the amp to appear to be in protect mode.

 

[luka]

he also wanted voltage, compared to gnd, of every pin of TL, check schematic, I think you can see were led is connected to

 

[Perry Babin]

Do you have the schematic diagram?

 

[luka]

I do, most of it anyway, need it?

 

[Perry Babin]

Yes. It sure would save a lot of time.

babin_perry@yahoo.com

 

[kimschips]

Yes. It sure would save a lot of time.

babin_perry@yahoo.com

The "protect led" is lightning at start when you turn on the amp and then the led turns off again when the power amp is startet op
allright

But not the power led

I will measure TL 494 for you all 16 pins🙂