I just saw a pic of the F version and mine is different.The relays are mounted on a small board soldered to the main board. I will post pic tomorrow but mine look just like this but with black relays.
Not my pic""
http://i598.photobucket.com/albums/tt70/oppermafkees/xm-3040/DSC02473.jpg
Not my pic""
http://i598.photobucket.com/albums/tt70/oppermafkees/xm-3040/DSC02473.jpg
IC505
1: 0.948
2: 0.275
3: 0.651
4: 1.879
5: -0.104
6: 11.60
7: -0.056
8: 3.148
The voltage was stable only for pin 6 and 8. The rest was going a little up and down.
Base on the date sheet for that IC pin 8 Vcc should be higher than that.I pull the IC and
got 15.65v on the Pad pin 8.I put the IC back in and soldered pin 8 and 5 .I check voltage again
and it went back to 3.148.
1: 0.948
2: 0.275
3: 0.651
4: 1.879
5: -0.104
6: 11.60
7: -0.056
8: 3.148
The voltage was stable only for pin 6 and 8. The rest was going a little up and down.
Base on the date sheet for that IC pin 8 Vcc should be higher than that.I pull the IC and
got 15.65v on the Pad pin 8.I put the IC back in and soldered pin 8 and 5 .I check voltage again
and it went back to 3.148.
The voltage on pin 8 is probably OK. Pin 1 is above the threshold for that input. That's the over-current detect input. Pulling Q505 should defeat that part of the protection circuit and allow you to determine if there is a true over-current fault or a fault in the protection circuit. The Qx06 transistors are the over-current detection transistors for the individual channels.
I pull each over-current transistor one by one but no change.I pull Q505 amp is out of protect ,but after about 1 min comes back in protect.when amp was out of protect i get good audio on all channel.
Q505 in circuit
E: 22.56
C: 22.62
B: 21.98
out if circuit pads read
E: 25.60
C: 3.04
B: 23.92
With Q505 out i get 1.096 on pin 1 of IC505.With all parts in circuit if i GND pin six or seven amp comes out of protect
Q505 in circuit
E: 22.56
C: 22.62
B: 21.98
out if circuit pads read
E: 25.60
C: 3.04
B: 23.92
With Q505 out i get 1.096 on pin 1 of IC505.With all parts in circuit if i GND pin six or seven amp comes out of protect
If IC505 has voltage on pin 1, the problem may be the thermistor or the connections to the thermistor. Try grounding pin 1 of IC505 to see if that prevents it from going into protect mode but be careful in case there is a real fault.
Grounding pin 7 shouldn't (as far as I can tell) prevent the amp from going into protect mode.
Grounding pin 6 simply switches on the relay drive transistor which engages the relays.
email me if you want the diagram.
babin_perry@yahoo.com
Grounding pin 7 shouldn't (as far as I can tell) prevent the amp from going into protect mode.
Grounding pin 6 simply switches on the relay drive transistor which engages the relays.
email me if you want the diagram.
babin_perry@yahoo.com
Hi guys. I have the same problem with this power amplifier, but I can't find suitable schematic for this device. On found schematic there is a connection between primary and secondary ground via resistor and capacitor. In my device there no such elements and difference between its levels is almost 3V! What is worst from my perspective, upc1237 driving relays is grounded to secondary ground, while relays are connected to primary ground. Any thoughts what can be wrong? Or maybe you have schematic?
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