Creek OBH-21SE doesn't power up after I've connected the DAC output during music playing to the headphone amp's output (RCAs). What did I do?! Could you help me please?
photo of the circuit board below
P.S: Creek's engraved msg on the back of the amp: "No user serviceable parts inside" is very discouraging.
photo of the circuit board below
P.S: Creek's engraved msg on the back of the amp: "No user serviceable parts inside" is very discouraging.
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Merlin, thanks for your help so far. Unfortunately I don’t have the schematics.
The first advice I got outside the forum: “Likely, you've cooked the op amps for the input circuit, and depending on their failures maybe other parts in series as well”
The first advice I got outside the forum: “Likely, you've cooked the op amps for the input circuit, and depending on their failures maybe other parts in series as well”
I've measured the DC voltage from ground to Vcc+ and the Vcc- of the 14-pin TL04CN chip and there are completely dif values. As far as I understand the two voltages should have the same magnitude (within a tenth of a volt).
Is this correct?
Is this correct?
I've been trying to troubleshoot the 14-pin TL074CN.
Please let me know if I'm doing it correctly. Thank you
- With the headamp's DC power OFF
- Multimeter in diode mode
- I've measured each pin to ground:
1(1OUT): 0.74V
2(1IN-): .0L
3(1IN+): 0.0V
4(VCC+): 0.95V
5(2IN+): 0.0V
6(2IN-): .0L
7(2OUT): 0.74V
8(3OUT): 0.74V
9(3IN-): .0L
10(3IN+): 0.0V
11(VCC-): 0.54V
12(4IN+): 0.0V
13(4IN-): 0L
14(4OUT) 0.74V
===
With the amp's DC power ON
Multimeter in V mode,
I've measure the VCC+/- to ground:
VCC+: 0.54V
VCC-: 0.0V
Please let me know if I'm doing it correctly. Thank you
- With the headamp's DC power OFF
- Multimeter in diode mode
- I've measured each pin to ground:
1(1OUT): 0.74V
2(1IN-): .0L
3(1IN+): 0.0V
4(VCC+): 0.95V
5(2IN+): 0.0V
6(2IN-): .0L
7(2OUT): 0.74V
8(3OUT): 0.74V
9(3IN-): .0L
10(3IN+): 0.0V
11(VCC-): 0.54V
12(4IN+): 0.0V
13(4IN-): 0L
14(4OUT) 0.74V
===
With the amp's DC power ON
Multimeter in V mode,
I've measure the VCC+/- to ground:
VCC+: 0.54V
VCC-: 0.0V
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Measurements without power aren't necessary. It seems the power doesn't arrive to your IC, have you checked the voltage regulator VR1 as I said in post 4?
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Sorry, I did and I found the following values:
DC Power on:
Ground to Vin: 0.48V
Ground to Vout: 0.49-0.51V
Ground to Vadj: 1.15V
DC Power on:
Ground to Vin: 0.48V
Ground to Vout: 0.49-0.51V
Ground to Vadj: 1.15V
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What's your voltage regulator: LM3XX LT3XXX?
If powered ON you have 0.48V there is something broken between the input DC and the voltage regulator, first I check the diodes because I didn't see nothing burned.
If powered ON you have 0.48V there is something broken between the input DC and the voltage regulator, first I check the diodes because I didn't see nothing burned.
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