Hi all, I’m a Little out of Ideas what the cause could be. Situation: recap and belt replacement of a dcc170. After starting the player shuts down. I noticed the empty Battery symbol in the display. Just to check if a failed the recap I removed them and used new capacitors.
Same issue as before, display is showing low batt and shuts down. What could be the cause? Thank you for your reply in advance. Roel
No not yet. Issue is that I can’t read the electrical drawings. So I don’t know where to measure the voltage. If somebody could point out the points on the print I’m able to check it. Is there somebody in this forum able to help?
I had the same problem with my DCC175. After replacing all the capacitors and belt, the problem persisted. I replaced the DCC175 main PCB by a normal 170 main PCB and it worked fine, so I was sure it was a problem with the 175 main PCB. I checked the internal power circuit you mentioned and found that the voltage of several pins QA28 and QA29 was incorrect (because it could only be turned on for 2-3 seconds, so I took the opportunity to measure the voltage within these 3 seconds),I marked the wrong voltages in the picture. I thought these two parts were damaged, but after I replaced them, the problem persisted. Do you have any other suggestions? Thank you very much!
Actually, I don’t understand the circuit diagram very well, but I have a little knowledge of physical circuits and some soldering skills, and I want to try to repair it myself.
The PD AIO line must measure 0V or “connected” to ground in operating mode.
If measured 3,5V the chips depending on the PD AIO line think they are in stand-by mode and Power Down. So check the player as long as it runs, not when it has powered down already.
If it still has high voltage in running state like Kinlywang had, I would advice to check this line for connectivity first. It runs from this board to the main board.
As a workaround you could try connecting the PD AIO line to ground. But this is all at your own risk.
Maybe first try a 1k resistor at the base of Q21-1/2 to ground, just to see if the player keeps running after doing that.
But the cause of this happening could be somewhere else of course… Like the fact that the power indicator shows an empty battery even when it is not.
Maybe that’s the main cause for the unit to power down. Because you replaced the main board and it worked, I would take a look at the power supply part of the main board itself.
I found the problem and solved it. You can try the same method.
This hole is corroded by the capacitor on the back of the board, causing the 5.6V voltage to be unable to RC06. Add a cable connection from the 2nd pin of QU02 to RC06.
Thank you for your reply good work!!! I will try it tonight and let you know if this helps for the two 170 players I have here. At least 1x 175 saved!
Edit: just made a picture of the position. And I didn’t noticed it before. Completely rusted at that point I need to check the print in the other direction tonight. This will take some more time I think.
Congrats on this wonderful job! Thanks for letting us know!
It certainly looks like electrolyte from a capacitor caused this corrosion.
I have no opened up DCC17x, but is there one at the other side of this board? Is it CU02 / 22uF? (bottom right on my schematic above)
According to your suggestion, I carefully checked the power circuit and finally found that the voltage here was abnormal. Thank you very much for your help.
I updated more pictures, including DCC170 and DCC175. There is a C306 (220μ 6.3V) capacitor on the back of the board. It is the capacitor that leaked and corroded the connecting lines on the board.