Could be a short. Depends on how accurate your multimeter is.
I would try to inject a low voltage and search for shorted components getting hot on the pcb. A thermal camera would be helpful.
DriversScrew
Member
Last Activity: 06-06-2024, 06:38 AM
Joined: 12-24-2021
Location: Bavaria
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That's what I did with a Dymo Type Label printer, too. It came with no DC input at all. Now no more 6xAAA batteries needed. Working fine for years....Leave a comment:
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A power supply can measure correct voltage with no load attached. This does not mean it is good, you have to measure under load....Leave a comment:
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Gigabyte GA-B150N Phoenix Wifi Schematic
So far I only could find a schematic for this model. A boardview would be helpful....
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Gigabyte GA-B150N Phoenix Wifi - no
I've a GA-B150N Phoenix Wifi mobo here not starting at all. So far I only could find a schematic for this model. A boardview would be helpful.
Pressing the power button no fans starting, cpu stays cool, no beeps. 1,0V PCH seems to come up.
Schematic [url]https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-desktop-motherboards-graphics-cards-and-pc-peripherals/bios-schematic-requests/3272010-gigabyte-ga-b150n-phoenix-wifi-schematic[/url]https://I've a GA-B150N Phoenix Wifi...nd a schematic -
Hello I'm a guy from germany trying to fix some "unfixable" devices from time to time.
Not only pc related, also industrial electronics and home automation devices.Leave a comment:
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If this picture [URL="https://taobao.hooos.com/goods_jAvmwVBf0tJD2AM2mvHBB2tJte-yz622os6KVP0v27iD.html"]found on the web[/URL] can be trusted, XM5084-ADJ or equivalent should be correct.
STI3408B seems to be one more alternative. They all use the 0.6V ref. and have identical pinout.If this picture [URL="https://taobao.hooos.com/goods_jAvmwVBf0tJD2AM2mvHBB2tJte-yz622os6KVP0v27iD.html"]found on the web[/URL] can be trusted, XM5084-ADJ or equivalent should be correct.
STI3408B seems to be one more alternative. They all use the 0.6V ref. and have identical pinout.IfLeave a comment:
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That would be possible.
The XM5084-ADJ seems to match, the datasheet mentions the 3µ3 inductor.
But strange enough, the voltage is off from 3,3V as it says Ref:0,6V, too....Leave a comment:
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Need help to identify SOT23-5 step-down converter to 3.3V marking E16q9
Hello everybody,
I need to replace a shorted SOT23-5 step down converter in a consumer audio device marking E16q9. What I found out from the board layout and measurements:
Vin: 5,0V
Vout: 3,3V (connecting to all 3V3 inputs of a N32905U3DN)
Pin1: ? (perhaps enable)
Pin2: GND
Pin3: Vout - connected to 3µ3 coil
Pin4: Vin
Pin5: Feedback, voltage divider, two resistors connect Vout-Pin5-GND, 680k+133k
I searched many datasheets, but no one seemed to match according the surrounding components.
Best similar parts I found were... -
Xiaomi Mi 11 Lite 5G Boardview
Anyone can provide a boardview (brd) file for this device?
Until now I only could find pdf version of schematic and board.... -
Re: Brother Maintenance Tools and repair help for QL-570
I did more measurements and found strange high voltage about 25V on the ON/OFF button connector (CN8) when it is unplugged. With the plugged connector this drops to the 2.5V mentioned before.
Unluckily my linked schematic doesn't show up.Leave a comment:
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Re: Brother Maintenance Tools and repair help for QL-570
Update:
When unplugged from mains power after some days I'm able to switch on normally. All functions are working for a short period (about one minute). After that the device seems to freeze.
I measure only about 2.5V on the connector for the ON/OFF button where the other buttons show 3.3V when upressed.
According to the service manual there are no components on the ON/OFF line, that could cause this behavior. R9 and R10 values measure ok....Leave a comment:
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Re: Asrock Z87 Extreme 4 Not powering on
RT8065ZQW (PU9) changed -> board back to life
I must mention, I also had to flash a good bios after this, like it had been corrupted from the dying regulator.Leave a comment:
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Brother Maintenance Tools and repair help for QL-570
Anyone can provide the software tools for Brother P-Touch QL-570?
According to the service manual there should exist
On the brother homepage I only can find autopoff.exe and a tool called ptsweep.exe.
I got the QL-570 as defective, but it powered up normal (voltages measured ok) with cutting and paper feed working until a paper roll and driver were installed on the connected pc.
The device now only shows a dim red LED light. Powering on/off doesn't work.
I'll do voltage measurements again to exclude an electrical/power supply problem.... -
Re: Asrock Z87 Extreme 4 Not powering on
I have the very same symptoms as dicky96 reported on an Asrock B85M-ITX.
After some measurements it looks like I get only about 0.35V on the PU9 chip for half a second the system tries to power up. It is the same RT8065ZQW as mentioned from anikin73.
The pin 8 (PGOOD) of this ic remains low.
RT8065ZQW datasheet:
[HTML]This pin is an open drain logic output
that is pulled to ground when the output voltage is not within
+/-12.5% of regulation point.[/HTML]
I will order the RT8065ZQW and...Leave a comment:
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Re: Repair Synology DS118 - fsbl fail - RAM already changed
Changed the flash chip, copied the content of original flash over before, but without any change.Leave a comment:
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Re: Repair Synology DS118 - fsbl fail - RAM already changed
As far as I know it isn't possible to simply change the flash bin file. You have to adjust serial and checksum, maybe other parameters, too?Leave a comment:
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Re: Repair Synology DS118 - fsbl fail - RAM already changed
No problem with erasing, flashing and verifying the content.
The flash chip itself (MX25L6433F) seems to be fine.
I wonder how I could measure the voltages of the RAM chips, if all are stable?
There are two unpopulated RAM places in DS118. Maybe I can check with an oscilloscope there?
[URL="https://semiconductor.samsung.com/resources/data-sheet/DS_K4A4G165WE_BC_I_Rev1_4-1.pdf"]I found the datasheet for RAM[/URL], but not for the "W27N 2227" device...Re: RepairLeave a comment:
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Re: Repair Synology DS118 - fsbl fail - RAM already changed
In my case only RTD1296 cpu commands are available. The console is connected via USB-TTL converter to the board.
So the fault must be in a very early stage. fsbl = "first stage boot loader"???
Edit: I managed to read the flash contents with a programmer. How to check if flash content/bin is valid?Last edited by DriversScrew; 05-15-2022, 04:51 AM.Leave a comment:
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Re: Repair Synology DS118 - fsbl fail - RAM already changed
Shouldn't there then be an error like
[CODE]SF: Detected MX25U6435F with page size 256 Bytes, erase size 64 KiB, total 8 MiB
*** Warning - bad CRC, using default environment
...
SF: Detected MX25U6435F with page size 256 Bytes, erase size 64 KiB, total 8 MiB
SF: 3014656 bytes @ 0x90000 Read: OK
SF: 4587520 bytes @ 0x370000 Read: OK
## Booting kernel from Legacy Image at 08000000 ...
Image Name: Linux-3.10.102...Leave a comment:
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