Amanero Isolator/Reclocker GB

[acko]

Enrico,

hold off desoldering just yet. Need a bit more time to figure how a 4.62V has appeared in the outputs when supply is 3.3V

 

[emyeuoi]

Ok... thanks Acko.

Actually this value surprise me too... looking the schematic I can't see from where the XO can take 4.62V

 

[miksi]

Enrico, what DMM you are using for measurements?

 

[emyeuoi]

Hi miksi,

is a new Fluke 17B but I can try to measure with another Fluke 117. I am quite confident in the measures I did

 

[emyeuoi]

Hi Acko,

I plan to cut the trace of the PCB just near the exit of the XO versus the pins 3 of the U3 and U5 to see if the 4.6Vdc are still there... I will do tonight if you don't have contraindications

 

[acko]

Ok... thanks Acko.

Actually this value surprise me too... looking the schematic I can't see from where the XO can take 4.62V

Hi Enrico,

When you get a chance try powering the XO from an external 3.3V supply instead and see. Jumpers need to be changed accordingly

 

[emyeuoi]

Hi Acko,

If I understand correctly you want to remove the K1 jumper and use the J2 connector instead if the J1. I have to install also the C9 and re-install the Q2 that we remove last night... correct?

 

[acko]

Hi Acko,

If I understand correctly you want to remove the K1 jumper and use the J2 connector instead if the J1. I have to install also the C9 and re-install the Q2 that we remove last night... correct?

Yes, this is right but you need not install C9 for the tests and Q2 can be left out permanently for the CCD575 XO.

 

[emyeuoi]

Yes, this is right but you need not install C9 for the tests and Q2 can be left out permanently for the CCD575 XO.

Ok, thanks. I will do when I am back at home... around 7pm Korean time

 

[acko]

Hi Acko,

I plan to cut the trace of the PCB just near the exit of the XO versus the pins 3 of the U3 and U5 to see if the 4.6Vdc are still there... I will do tonight if you don't have contraindications

Sorry, I missed your post earlier. Please do not cut any tracks at this stage but for your setup U5 is not necessary and can be removed.

 

[emyeuoi]

Hi acko,
No problem... please don't sorry, you are kindly help me with this troubleshooting
To recap: I will remove U5 and move the psu to J2 with 3.3Vdc removing also K1. Correct?

 

[acko]

Hi acko,
No problem... please don't sorry, you are kindly help me with this troubleshooting
To recap: I will remove U5 and move the psu to J2 with 3.3Vdc removing also K1. Correct?

Yes, go ahead with these

 

[emyeuoi]

Here we are.... 1.52 Vdc

Should be nice to understand who is the culprit but the XO is working... now I need some time to hookup again everything and to play some music
Thanks acko for your help... really appreciate
Enrico

 

[emyeuoi]

Acko, please disregard my previous post

I am sorry and a little embarassed, when I take the measurement I forgot to re-connect the input to the 2 psu... when I re-hookup the psu the pin 3 of the XO is back 3.34Vdc

 

[acko]

No problems, will press on
Can you now measure the actual supply voltage and the dc current drawn from the XO supply

 

[emyeuoi]

Thanks Acko
The supply voltage is 3.312Vdc but I can't read the current with the fluke 17B. Just when I put the probes of another fluke between the 2 and 4 to read the Vdc I can read 0.2 microA in the other in series

 

[acko]

Supply current for the CCHD575 should be 15-25mA as per data sheet specs
Please check again to confirm. Try using just the current meter only and set to dc mA range if available

 

[emyeuoi]

The amperometer in series to the 3.3Vdc for the XO is measuring 00.00

 

[emyeuoi]

00.00 mA and 00.00 uA

 

[acko]

00.00 mA and 00.00 uA

Possible issue with the XO. Please desolder it carefully, attach wires to the pads of the removed XO and try powering it up separately with a 3.3V supply. Then check its output.