Hifonics GEN X Zeus

mike49504

Member
2006-09-22 8:32 am
Im in the process of rebuilding 1 of theese amps again since this one came in with no outputs or power supply fets in the board and alot of other stuff missing.

My question is the outputs that are being used in this amp are 2SA1302 and 2SC3281 how do i figure out what outputs go in what locations?
 

Perry Babin

Member
Paid Member
2003-11-20 11:01 am
Louisiana
www.bcae1.com
Find the rectifiers that have their right leg that read 0 ohms to the non-bridging speaker terminals. The left leg of those rectifiers will connect to the center leg of the NPN output transistors.

If you power the amp up before reinstalling the outputs, you can check the voltage on the center solder pads for the outputs. The NPN transistors will have positive rail voltage on the center pads. The PNP outputs will have negative rail voltage on the center pads.
 

mike49504

Member
2006-09-22 8:32 am
Ok back to this amp. I replaced all power supply fets, and outputs and a few transistors.

AMp doesnt produce rail voltages or regulated voltages. Heres what i have on the TL494 and the LM324

TL494
1:3.30
2:9.24
3:9.70
4:3.01
5:7.91
6:8.94
7:3.76
8:13.92
9:2.78
10:2.78
11:13.92
12:13.13
13:10.29
14:10.28
15:10.28
16:2.91

LM324
1:0
2:11.72
3:0
4:13.20
5:0
6:6.59
7:0
8:0
9:12.10
10:8.78
11:0
12:12.04
13:6.60
14:11.89

Any ideas on what to check for next?
 

mike49504

Member
2006-09-22 8:32 am
Replaced a couple transistors and heres what i have now. AMP still isnt producing rail voltage.

TL494
1:2.16
2:2.14
3:3.08
4:0.22
5:1.45
6:3.44
7:0
8:13.88
9:0.93
10:0
11.93
12:13.02
13:4.92
14:4.92
15:4.93
16:10.98

LM324
1:11.68 then 0
2:11.68
3:12.01 then 0
4:13.68
5:11.33
6:6.52
7:11.28
8:0
9:11.92
10:8.68
11:0
12:11.99
13:6.54
14:11.85
 

mike49504

Member
2006-09-22 8:32 am
Could it be possible i have a bad 494 If i tap it lightly the amp will come on and produce audio and the voltages on the 494 are correct. Then after 1 min it goes dead again and if i tap it it will work again I reflowed the solder to all pins but i have the same issue
 

mike49504

Member
2006-09-22 8:32 am
I got this amp back in for repair the guy said his speaker wires touched when hooking it up.

I opened it up and found a bad output replaced it and now the amp has no output and has the following voltages on the output terminals.

Left channel:0.42 volts

Right channel:0.42 volts

I have 0 volts across every emitter resistor

I have rail voltages -59.8 and positive 54.0

On the op-amps that sit on the input board i have the following voltages
( 2068D)

1:111.45
2:9.76
3:9.42
4:10.0
5:9.42
6:10.42
7:11.46
8:12.21

Any ideas on what to check?
 

mike49504

Member
2006-09-22 8:32 am
Well got this thing back again..

It lasted from March to now with no problems.


He said he took the card out and flipped it around with the amp on ..


So now Pin 16 on the 494 is high once again its at 12.94 when powerd up and drops to 10.94 volts and remains constant..


Pin16 connects directly to a diode then branchs off to something else which i havent tracked down yet..


Is Pin 16 usually controlled by a transistor ?