This is a bit of a confusing amp given the crossover modules and jumpers, and a 37 page manual which tries to explain things.
Amp came in and was able to power up, but power terminals were loose to PCB. All but CH5-6 were able to work but Im not sure if those channels were tied to inputs other than CH5&6. Someone had played around with jumpers, wires, and settings and none of it made sense and didn't follow the manual's suggestions so I pulled all settings and modules out. After repairing the power block, I tried following the manual for 1-to-1 jumper settings but there is none; so I went with the factory default settings on the first page (Page 7 w/0 AC502). Amp now goes straight into protect. I pulled ALL jumpers and modules out and still straight into protect. I dont know if the problem is in the pre-amp, configurations, or something else.
Manual I've been following here: V:\ADS manuals\M860 manual.tif - DirectedDealers.comhttp://www.directeddealers.com › ads-mobile › ad...
For an extremely brief moment I can see drive signal FLASH on pins 9&10 of the TL.
TL494
1. 0
2. 3.510
3. 3.510
4. 0.006
5. 1.461
6. 3.369
7. 0
8. 14.40
9. 0.054
10. 0.054
11. 14.40
12. 14.42
13. 4.95
14. 4.95
15. 3.510
16. 3.510
Amp came in and was able to power up, but power terminals were loose to PCB. All but CH5-6 were able to work but Im not sure if those channels were tied to inputs other than CH5&6. Someone had played around with jumpers, wires, and settings and none of it made sense and didn't follow the manual's suggestions so I pulled all settings and modules out. After repairing the power block, I tried following the manual for 1-to-1 jumper settings but there is none; so I went with the factory default settings on the first page (Page 7 w/0 AC502). Amp now goes straight into protect. I pulled ALL jumpers and modules out and still straight into protect. I dont know if the problem is in the pre-amp, configurations, or something else.
Manual I've been following here: V:\ADS manuals\M860 manual.tif - DirectedDealers.comhttp://www.directeddealers.com › ads-mobile › ad...
For an extremely brief moment I can see drive signal FLASH on pins 9&10 of the TL.
TL494
1. 0
2. 3.510
3. 3.510
4. 0.006
5. 1.461
6. 3.369
7. 0
8. 14.40
9. 0.054
10. 0.054
11. 14.40
12. 14.42
13. 4.95
14. 4.95
15. 3.510
16. 3.510
Yes 3.510vdc. The following pins 2, 3, 15 are tied together. Pin 16 also same voltage on it, 3.510vDC on all pins no matter the input voltage.
Rail caps are 35v. I'm seeing about +-22vDC rail as the brief pulse must be charging the rail caps.
Rail caps are 35v. I'm seeing about +-22vDC rail as the brief pulse must be charging the rail caps.
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Discharge the rail caps while the amp is powered up to see if it tries to recharge them. Do this with either a high-value resistor or an incandescent lamp (120v, not 12v).
I tried that with a 5w 2.7k resistor but not sure that helped. Amp stayed powered down.
I lifted a 2.2k resistor that was connected to pin #16 of the 494 and the amp powered up. Amp seems to be working on all 8 output channels. All opamps seem to have good voltage on them. This 2.2k resistor is connected back through what looks like positive rail voltage coming from somewhere. I say somewhere because its branched off in multiple directions and connected to 8x MPSA56 transistor collectors at the very least.
I lifted a 2.2k resistor that was connected to pin #16 of the 494 and the amp powered up. Amp seems to be working on all 8 output channels. All opamps seem to have good voltage on them. This 2.2k resistor is connected back through what looks like positive rail voltage coming from somewhere. I say somewhere because its branched off in multiple directions and connected to 8x MPSA56 transistor collectors at the very least.
Without many (any?) exceptions, when the voltage matches so closely on the error amplifier input, that indicates that the power supply is regulated.
What I wanted to see, with the drain resistor (or lamp) is if the rail voltage remained at the same ±22v or if it drained off.
What I wanted to see, with the drain resistor (or lamp) is if the rail voltage remained at the same ±22v or if it drained off.
With the 2.2k resistor lifted, the amp powers up but the supply is operating in an un-regulated state.
The drain resistor will drain the rail voltage.
The drain resistor will drain the rail voltage.