Eclipse XA1200 ICE

[ray9043]

Hi everyone¡¡

Today comes to me an eclipse xa1200 ice amp.

I dont test any amp, before i check the inside. In this one i find a rarely and 100% sure bad conection on the irf1010 ps mosfet, see the image.

So i take off all the ps mosfets and test it. No power, no 12v on the tl494 so replace the remote signal transistor. 12v on vcc and c1 and c2 of the tl. Now i have around 4-5v on the tl outputs, but im sure the ps mosfets drivers are grone. Anyone here have the shematic or the corrct part nunber for q919 and q921?

Thanks!

 

[twilliar]

The IRF1010 is GDS 1,2,3 as per the datasheet.
Or am I seeing the board wrong?

 

[ray9043]

In this amp the mosfets are sourcing +b to the toroidal instead of sinking. The gate are the first pin, with 100 ohm gate resistor. Someone put the mosfets with the gate on the source.

 

[Perry Babin]

Look at the gate drive with a scope instead of a multimeter.

 

[ray9043]

I dont have an oscope right now, only multimeter.

I have 0v because the gate signal transformer is off, i take off both transistors. I need the correct part number for those transistor and test again if the transformer had gate signal.

 

[Perry Babin]

The 'outputs' on the 494 can be 8, 9, 10, or 11. You didn't say which had signal.

Which leg of the driver transistors is connected to ground?

 

[ray9043]

8 and 11 had 12v, 9 and 10 are the outputs. Both driver transistor had 12v on center leg, it has a transformer for the gate pulses, like the mtx amps.

 

[Perry Babin]

MTX takes drive from 8 and 11.

I think your circuit may be like the sony circuit.
http://www.bcae1.com/temp/sony - XM-D400P5_Car Power Amplifier SM.pdf

 

[ray9043]

Thanks Perry! Its the same circuit. I put irf1010 and find another problem, someone do a mess with evrything in the amp. The rectifiers was in the bad side!

Now the ps turn on, then protects, about 35 volts then go off. Im locking for bad traces or solder juntions.

 

[ray9043]

4 output mosfets in place. Amp turns on, play fine 2 songs and BAM one cap blown, regulators area, +20 and -20 volts on the opamps supply. I will check the regulators.

 

[twilliar]

Having reversed rectifiers plays havoc on the electrolytic capacitors.

 

[ray9043]

New regulators in place. Test with 7915 and 7815. 817 optocoupler damaged, i replace it. Now i have +-15 volts on opamps, adc and ice board. No output, no sound. Any ideas here?

 

[Perry Babin]

Post a good photo of the entire board.

 

[ray9043]

Everyone smd transistor and resistor checked. Now i think i found the problem, the ssm2018 ic. If i touch the ic leads, the speaker make noises, so i think the ice ic's are working. No heat from mosfets or anything else.

I found datasheet for the ic but its obsolete and discontinued

 

[ray9043]

Bypassed the ssm2018 ic. The amp plays fine. Tomorrow i will test it more time.