The problem may be in the module.
Pin 4 of the 324 is the B+ terminal. Pin 11 is ground.
If this is a Zed amp (will have Zed audio in the silkscreen), contact them to see if you can get a schematic diagram or at least an internal diagram for the power supply module.
Zed Audio Corporation
Pin 4 of the 324 is the B+ terminal. Pin 11 is ground.
If this is a Zed amp (will have Zed audio in the silkscreen), contact them to see if you can get a schematic diagram or at least an internal diagram for the power supply module.
Zed Audio Corporation
What problem module do you mean? The 324 or something else? I can try replacing the 324...
I confirmed Pin 11 is connected to ground. Pin 4 - little to no voltage. I'll keep picking around.
This is a Zed amp. Unfortunately I dont know how much help Zed is going to give me on this amp. See I actually just got this amp back from Steve Mantz after he quoted me almost $200 to fix it which I didnt think it was worth. He did say there was something wrong with the power supply and that all the power supply fets needed replacing... Not to say he was wrong, but I cannot find a bad fet on this board. I had him send me back the amp under my dollar under the thought I could possibly fix it myself. I feel if I ask him then I'm really just taking business away that I otherwise would have paid him to do - Thats not too professional. Likewise, in another thread about a Gen X Hifonics, I saw Steve post up that he didnt have any of the Schematics for the old Hifonics stuff. Maybe he does, maybe not. If theres no other way then I'll probably just put this amp aside for awhile. Maybe Zed will forget they had it, maybe they could be helpfull in the future.
This is a good amp, possibly better than all the others I have (Including the PPI PC2150). I'd like to try and fix it. Unfortunately I'm affraid that some of the 'Zed' branded components that look like resistor networks are not replacable except through Zed.
I confirmed Pin 11 is connected to ground. Pin 4 - little to no voltage. I'll keep picking around.
This is a Zed amp. Unfortunately I dont know how much help Zed is going to give me on this amp. See I actually just got this amp back from Steve Mantz after he quoted me almost $200 to fix it which I didnt think it was worth. He did say there was something wrong with the power supply and that all the power supply fets needed replacing... Not to say he was wrong, but I cannot find a bad fet on this board. I had him send me back the amp under my dollar under the thought I could possibly fix it myself. I feel if I ask him then I'm really just taking business away that I otherwise would have paid him to do - Thats not too professional. Likewise, in another thread about a Gen X Hifonics, I saw Steve post up that he didnt have any of the Schematics for the old Hifonics stuff. Maybe he does, maybe not. If theres no other way then I'll probably just put this amp aside for awhile. Maybe Zed will forget they had it, maybe they could be helpfull in the future.
This is a good amp, possibly better than all the others I have (Including the PPI PC2150). I'd like to try and fix it. Unfortunately I'm affraid that some of the 'Zed' branded components that look like resistor networks are not replacable except through Zed.
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Getting back to this amp now... I'm seeing something strange on the 494.
With Bat + & - connected and rem disconnected, I get the following voltage readings across the 494:
1: .025
2: 4.7
3: 4.7
4: .2
5: 1.4
6: 3.3
7: 0
8: 12
9: 0
10: 0
11: 12
12: 12
13: 4.7
14: 4.7
15: 4.7
16: 12
Shouldnt I be seeing no voltage? Comparison with REM connected:
TL494CN
1: 0.772
2: 5.02
3: 4.73
4: 0.215
5: 1.411
6: 3.388
7: 0
8: 12.27
9: 0
10: 0
11: 12.27
12: 12.26
13: 4.97
14: 4.96
15: 4.97
16: 11.46
With Bat + & - connected and rem disconnected, I get the following voltage readings across the 494:
1: .025
2: 4.7
3: 4.7
4: .2
5: 1.4
6: 3.3
7: 0
8: 12
9: 0
10: 0
11: 12
12: 12
13: 4.7
14: 4.7
15: 4.7
16: 12
Shouldnt I be seeing no voltage? Comparison with REM connected:
TL494CN
1: 0.772
2: 5.02
3: 4.73
4: 0.215
5: 1.411
6: 3.388
7: 0
8: 12.27
9: 0
10: 0
11: 12.27
12: 12.26
13: 4.97
14: 4.96
15: 4.97
16: 11.46
There is more from the small pad in Photo just to the right of Pin 8...
*Done editing post*
Edit: The trace os also going to Q8 and Q9 pin 2, as well as Q2 pin 1.... Also Prot 2 pin all the way on the right. Theres also another trace leading to the LED connector where the amp has illuminating incondecant bulbs but no circuits.
*Done editing post*
Edit: The trace os also going to Q8 and Q9 pin 2, as well as Q2 pin 1.... Also Prot 2 pin all the way on the right. Theres also another trace leading to the LED connector where the amp has illuminating incondecant bulbs but no circuits.
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I need a photo of good quality of the whole circuit board of this amp and a good close up pic of the power supply section of the board. I had the same problems with a zeus amp awhile back . I will also try to help troubleshoot this for you since mine was an open trace which i thought at first had nothing to do with the 324 .
That is correct.
Hey mike, thanks for jumping in. I dont have a camera in front of me to take a new picture until I get home this evening; but I do have some pictures I'd previously taken of certain areas of the PCB. I put all the current pictures I have of the thor into this album:
Hifonics Thor X pictures by unclemeat2010 - Photobucket
The 'gold outside' would be the transformer pad with two gold wires. Pin 8 wouldn't be connected to that. It's connected to the primary center tap (2 red. 2 gold). If that's the case, the 12v on the IC (pin 8, 11 and 12) will be constant.
To see if there are any other problems, I'd suggest that you remove the TL494 and install it in a socket but leave pin 16 out. Solder a wire to pin 16 and ground it. Does that allow the amp to power up and produce rail voltage?
To see if there are any other problems, I'd suggest that you remove the TL494 and install it in a socket but leave pin 16 out. Solder a wire to pin 16 and ground it. Does that allow the amp to power up and produce rail voltage?
Sounds like a plan, but either I've gotta order a new TL494 or perhaps just clip pin #16 near the base of the PCB in a way that I can re-attach it later. I dont want to try removing TL494 by iron in one piece in fear of hurting this pcb. I'll think of something, but I presume I cannot try applying ground to pin #16 while it is in circuit with other components.
I don't know what's driving it. If grounding it draws excessive current through whatever's driving it, it could cause other components to fail. If it causes something in one of the modules to fail, it could make it that much more difficult to repair.
Remember, clamp all transistors before applying power.
Remember, clamp all transistors before applying power.
A little trick I picked up with the transistor clips. Cut the longer ones in half and it is 10x easier to install/remove multiple times:
Amp is ready for power testing:
Per suggestion, I was able to cleanly clip the 494's Pin 16 from the top of the PCB using an exacto blade. Using a shielded alagator clip for bridging this pin to other sources (Ground):
This amp IS made by Zed. The POS card I can never figure out which way it needs to be installed. It goes in 4 different ways and is not descriptive of how it should go. Anybody?
Next up... Testing WITH power
Amp is ready for power testing:
Per suggestion, I was able to cleanly clip the 494's Pin 16 from the top of the PCB using an exacto blade. Using a shielded alagator clip for bridging this pin to other sources (Ground):
This amp IS made by Zed. The POS card I can never figure out which way it needs to be installed. It goes in 4 different ways and is not descriptive of how it should go. Anybody?
Next up... Testing WITH power
Lowering the bias pots didnt help. I pulled the board and started testing the transistors a few times. So far I find them all coming up normal from what I can tell via the DVM. There are no shorts between pins, and diode checks are good. All the transistors diode check OK by the dvm. I even checked most of the little ones on the driver board and they seem OK too.
Am I doing this right? Should the large 1317 and 1975 transistors diode-beep at me in all positions?
Am I doing this right? Should the large 1317 and 1975 transistors diode-beep at me in all positions?
No but I sure can get one. What wattage should the bulb be?
Hm? My generator makes tones.
Edit: i wonder if I should pick up something like this from eBay or Mouser so I can see what amps draw that I am working with.
50A Analog DC Amp Meter Current DC Panel Meter Ampmeter - eBay (item 170562560090 end time Dec-05-10 20:04:32 PST)
Hm? My generator makes tones.
Edit: i wonder if I should pick up something like this from eBay or Mouser so I can see what amps draw that I am working with.
50A Analog DC Amp Meter Current DC Panel Meter Ampmeter - eBay (item 170562560090 end time Dec-05-10 20:04:32 PST)
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