vbogoev
Member
Last Activity: 02-18-2024, 03:27 PM
Joined: 11-15-2021
Location: Sofia
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U1 is voltage regulator located in the top left corner next to the relay.... -
IR lamp Medisana IR 850 ,Identifying 14 pin chip
Hello,
I have a non-working IR lamp Medisana IR 850.
Initially, when I plug the item into mains I had to press the button once to start it. The function is pretty simple - every button press add 5 min to timer (probably the unknown IC I am looking for) up to 15mins. The main problem was that the relay was not closing for some reason and the lamp did not glow.
I found the problem which was a blown zener dionde, but unfortunately while measuring on live my probe slipped and shorted the black capacitor next to the zener diode with mains and it blew up...
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Re: GYSMI 160p welder transistors shorted
Thank you guys for the responses. I'll try it with R100, Didn't think of the gate drive, but you're right. I'll check it as well. I'll update after I replace all the components..Leave a comment:
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GYSMI 160p welder transistors shorted
Hello,
Here I have GYSMI 160p welder with no output. Otherwise the machine is starting, the fan is spinning, but the output is zero... I disassembled the welder and found the problem. 3 out of 6 transistors are shorted, and 3 pairs of 4 resistors are burned... There's also 1 burned "ultra fast diod" on another board that is connected to the transformer. My question is how can I identify these burned resistors, I have no idea what value they should be, also I am not able to find any image of the board over the internet... The other part numbers are clearly visible, so I... -
Re: Read eMMC chip using SD card reader
OK, found the problem. It was me of course...
The schematic show the chip pinout when it's upside up, I interpreted it as upside down as the pinout is symmetric.
Anyway, I successfully read the IC but it was not possible to open the userdata volume using Linux Reder program. Not sure it the content is encrypted. However, I successfully opened the system volume.Leave a comment:
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Re: Read eMMC chip using SD card reader
Thanks for the advices. I started 3 times from the beginning, but at the end I am pretty sure everything is connected as described. I am not sure if RSTN should be pulled up in order to enable the chip, but from the datasheet it seems like this is how it is supposed to work.
Indeed, at first I didn't know for the card detect switch, but then I plugged another card in the socket, wrapped with capton tape on the pins and now card detect pin on the chip is ON.
However, there's no voltage passed...Leave a comment:
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Read eMMC chip using SD card reader
Hello,
I found several sources where guys successfully read eMMC chip using a SD card reader. I was interested to try it, just to practice micro soldering, but for some reason I am unable to read the chip. The chip is known working one (desoldered from an old working device) model Samsung KLM8G1WE4A-A001. The card reader is Transcend USB 3.0. So basically I've connected everything as it is described in the schematic, but the sd card reader didn't even start to blink. I am not sure what I am missing, so I'll appreciate some help...
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Re: Lenovo S6000 won't turn on. Data recovery needed.
Any suggestions, anyone? How would you proceed?Leave a comment:
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Re: Lenovo S6000 won't turn on. Data recovery needed.
SD card connector is placed on a daughter board which is not connected while testing.
This is the log of the working one (again the daughter board is disconnected, but the tablet is fully working):
[CODE][PWRAP] pwrap_init_preloader
[PWRAP] pwrap_init
[PWRAP] _pwrap_init_sidly [Read Test] pass,SIDLY=0 rdata=5AA5
[PWRAP] _pwrap_init_sidly [Read Test] pass,SIDLY=1 rdata=5AA5
[PWRAP] _pwrap_init_sidly [Read Test] pass,SIDLY=2 rdata=5AA5
[PWRAP] _pwrap_init_sidly...Last edited by vbogoev; 06-20-2023, 07:50 AM.Leave a comment:
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Lenovo S6000 won't turn on. Data recovery needed.
Hello,
Here I have the mentioned tablet with motherboard s6000-mb-h401. The tablet won't turn on, no display, charging normally. I manage to connect to UART port and got this output when I try to start it:
[CODE][PWRAP] pwrap_init_preloader
[PWRAP] pwrap_init
[PWRAP] _pwrap_init_sidly [Read Test] pass,SIDLY=0 rdata=5AA5
[PWRAP] _pwrap_init_sidly [Read Test] pass,SIDLY=1 rdata=5AA5
[PWRAP] _pwrap_init_sidly [Read Test] pass,SIDLY=2 rdata=5AA5
[PWRAP] _pwrap_init_sidly [Read Test] pass,SIDLY=3 rdata=5AA5
[PMIC_WRAP]wrap_init pass,the...Last edited by vbogoev; 06-20-2023, 07:51 AM. -
iPad 4 not powering on. Missing PP3V0_GRAPE
Hello,
I bought an iPad 4 from eBay which is not powering on and wanted to troubleshoot the problem just for fun.
But the fun ended when I stuck... I don't know what to do next and I'll be thankful for a bit of help.
What I know so far:
Pluging the iPad to the charger charging the battery with around 2.3-2.4A, which is OK IMO.
Pressing the power button does nothing. Press and hold the power button + home button (to reset the device) does nothing (it is resetting but still doesn't turn on).
I dissassembled the tablet...Last edited by vbogoev; 11-19-2021, 04:48 PM. -
Re: New Members - please post your introductions here
Hi. I'm from Bulgaria and started with repairing electronics as a hobby. This forum looks really helpful for such things so here I am.Leave a comment:
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