Yes, it was a friend of mine that did kill his isolators on his DAM. I swapped them out with new ones for him, it took me about 15 minutes.
But Sunsun22's problem is way more complex.. The bast case scenario would be blown isolators as they are the easiest to replace. I would hate to have to swap out an FPGA (BGA I believe).
But Sunsun22's problem is way more complex.. The bast case scenario would be blown isolators as they are the easiest to replace. I would hate to have to swap out an FPGA (BGA I believe).
First try, lifted the +ve rail of MCU but unluckily, it is not the core of problem.
I can't do anything on the FPGA but I can take it to a workshop and have it done but this would be the last attempt.
I can't read the light markings on other ICs. Can anyone tell me where is/are the isolator(s) and their respective part number?
By the way, can anyone give me the resistance on the 3.3V regulator between input to GND and output to GND?
Thank you very much.
I can't do anything on the FPGA but I can take it to a workshop and have it done but this would be the last attempt.
I can't read the light markings on other ICs. Can anyone tell me where is/are the isolator(s) and their respective part number?
By the way, can anyone give me the resistance on the 3.3V regulator between input to GND and output to GND?
Thank you very much.
The isolators should be U36 and U34 (and probably the other similar-looking 8 legged IC beside J3) as per Soren's post here
Dimdim can probably verify since he has actually done the operation!
Does your green indicator light still stay on (lock) and flash (on sample rate change)? Since you need a serial adapter anyways, probably good to just get one to test whether your RS232 and fpga is still alive.
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Thanks Ristar, I will wait for Dimdim's verificaiton. What is/are the part number of isolator(s)?
The green led does not light up.
The green led does not light up.
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It sounds like the damage on your board may be quite extensive. While I haven't killed anything, I do remember the green LED continuing to blink when I forgot to connect the 3.3v supply.
Sorry I can't help more... hopefully Dimitri replies with his advice soon. You may also want to consider maybe PMing Soren to see if he would be willing to repair for a fee for you?
Sorry I can't help more... hopefully Dimitri replies with his advice soon. You may also want to consider maybe PMing Soren to see if he would be willing to repair for a fee for you?
Sending this to Denmark and returning to Hong Kong would be the cost of a new board. They only use UPS.
This is really something I can't understand. Why they insist to use UPS only? A little bit of paper work in using postal service would help customers to pay much less on logistics thus may increase their sales.
This is really something I can't understand. Why they insist to use UPS only? A little bit of paper work in using postal service would help customers to pay much less on logistics thus may increase their sales.
Here they are, in the crude red circle:
The part number is SI8620BB-B-ISR but it's near its E.O.L. so a better choice would be the ISO7420FEDR. It's a drop-in replacement.
I'll measure them and let you know later today, assuming that you mean the resistance with the LDO soldered on the board. It would be pretty hard (read: risky) for me to desolder it from the board just to measure the resistance. It might be easier for other fellows, like the ones that have already replaced their on-board LDOs with external PSs.
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The part number is SI8620BB-B-ISR but it's near its E.O.L. so a better choice would be the ISO7420FEDR. It's a drop-in replacement.
The ISO7420FEDR is 2.5 times more expensive than Si8620BB. Is there any superiority of ISO7420FEDR over Si8620BB?
The ISO7420FEDR is 2.5 times more expensive than Si8620BB. Is there any superiority of ISO7420FEDR over Si8620BB?
No, not really. If you can get the 8620 part, you should definitely go for that one. In my case both of my preferred suppliers (Mouser and RS) were out of stock, so I went with the ISO part.
OK, so GND to input measures close to 1.5M (it takes a while for the caps to charge), GND to out measures at ~10K (fluctuates a bit).
Hi Dimdim,
The measurement on the input to GND looks OK with 2M but the output to GND only shows 2.5 ohmes which is a sign that there should be a damaged part(s) after the 3.3V. However, I have no clue but the MCU is not the victum because I lifted its +ve rail and the reading remains unchanged.
I am still not able to purchase the replacing parts in Hong Kong because the old one is out of stock but the new one comes with a minimum order of 10 that I have no use for the remaining ones.
By the way, what is the temperature used to desolder the isolators?
Thanks
The measurement on the input to GND looks OK with 2M but the output to GND only shows 2.5 ohmes which is a sign that there should be a damaged part(s) after the 3.3V. However, I have no clue but the MCU is not the victum because I lifted its +ve rail and the reading remains unchanged.
I am still not able to purchase the replacing parts in Hong Kong because the old one is out of stock but the new one comes with a minimum order of 10 that I have no use for the remaining ones.
By the way, what is the temperature used to desolder the isolators?
Thanks
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I believe that I went with less than 300oC on the rework station, perhaps 280o. I'll have a look later and let you know.
Did you figure out all of the parts that are powered by the 3.3V? They should include the ICL chip (U39), the EEPROM (U38) and the clock (U8).
Did you figure out all of the parts that are powered by the 3.3V? They should include the ICL chip (U39), the EEPROM (U38) and the clock (U8).
I have not figured out what are the parts that depends on the 3.3V. The answer from Soekris is useless - "there is no user serviceable part on the board".
I can identify where is U38 but if it is gone, there should be some programs inside that it would be useless to drop in a replacement. Am I correct?
I can't identify the ICL chip (U39), can you show it to me?
Does the U8 clock have a drop in replacement? What is the part number?
Thanks
I can identify where is U38 but if it is gone, there should be some programs inside that it would be useless to drop in a replacement. Am I correct?
I can't identify the ICL chip (U39), can you show it to me?
Does the U8 clock have a drop in replacement? What is the part number?
Thanks
You do have a point - it probably holds the FPGA's code.
It's to the right of the RS-232 header (J10).
It's an Si514.
Soekris R2R is dead
Si514 is also a programmable crystal. Is this just a drop in replacement or do I need to "programe" it before I can replace?
Si514 is also a programmable crystal. Is this just a drop in replacement or do I need to "programe" it before I can replace?
AFAIK the Si514 does not retain its programming on power down anyway, so it should be safe to just replace it.
Finished mine finally after having it in a cut up PSU case for months. Bought another Ghentaudio case as I loved the build quality of the one I got for my ncore project a lot.
I installed a USB hub internally which exposes both the Amanero and the dam serial port. The USB to serial converter is fully isolated.
The mute circuit is kind of a mess, I basically went with what works as I'm not a complete genius in electronics.
The little board in the middle is basically a DC power switch that provides a fast switched +12V from the shunt regulator. There is an AC feeder from one of the secondary windings from the transformer which powers a tiny opto-isolator that tells the relay to open or close via a mosfet, which provides the immediate switching when the mains switch is switched on or off. This board powers the mute shunt which is mounted directly to the dam.
The mute shunt connects to the LED pin, if signal is blinking it turns off the relay (normally closed) which shunts the dam outputs, when LED signal is solid, relay is turned on, opening the contacts thus allowing audio to pass. Upon poweron, the LED is blinking, so the relay coil remains off until the dam receives a lock.
Also since I always have the serial port, I simply use that to switch inputs and obtain dam status.
The shunt regulator I'm using used to use an extremely noisy (physically) pancake/bobbin style transformer (likely noisy due to the copper ground plane of the PCB). I hacked in the holes and cut out traces to install a nice toroid.
TODO in order of importance:
Install an in-line mains fuse. (!!! tomorrow)
Drill out left/right holes larger so the RCA connectors can fit.
Find a USB Type B connector that will fit rather than a Type A with a hacked together male to male cable I made to use it.
Maybe install some mains filtering, although shunt regulator works well...
Someday install a coaxial SPDIF, but no current need for it however as toslink and Amanero is sufficient for my purposes.
Feedback is always welcome.
Full size images
http://i.imgur.com/DfYkdG6.jpg
http://i.imgur.com/QU09H2s.jpg
I installed a USB hub internally which exposes both the Amanero and the dam serial port. The USB to serial converter is fully isolated.
The mute circuit is kind of a mess, I basically went with what works as I'm not a complete genius in electronics.
The little board in the middle is basically a DC power switch that provides a fast switched +12V from the shunt regulator. There is an AC feeder from one of the secondary windings from the transformer which powers a tiny opto-isolator that tells the relay to open or close via a mosfet, which provides the immediate switching when the mains switch is switched on or off. This board powers the mute shunt which is mounted directly to the dam.
The mute shunt connects to the LED pin, if signal is blinking it turns off the relay (normally closed) which shunts the dam outputs, when LED signal is solid, relay is turned on, opening the contacts thus allowing audio to pass. Upon poweron, the LED is blinking, so the relay coil remains off until the dam receives a lock.
Also since I always have the serial port, I simply use that to switch inputs and obtain dam status.
The shunt regulator I'm using used to use an extremely noisy (physically) pancake/bobbin style transformer (likely noisy due to the copper ground plane of the PCB). I hacked in the holes and cut out traces to install a nice toroid.
TODO in order of importance:
Install an in-line mains fuse. (!!! tomorrow)
Drill out left/right holes larger so the RCA connectors can fit.
Find a USB Type B connector that will fit rather than a Type A with a hacked together male to male cable I made to use it.
Maybe install some mains filtering, although shunt regulator works well...
Someday install a coaxial SPDIF, but no current need for it however as toslink and Amanero is sufficient for my purposes.
Feedback is always welcome.
Full size images
http://i.imgur.com/DfYkdG6.jpg
http://i.imgur.com/QU09H2s.jpg
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