Following this guide (https://www.reddit.com/r/thinkpad/co...g_and_flashing) i re-flashed my t480s BIOS using an external (CH341A) programmer. The flash didnt work, so i reverted back to my BIOS backup successfully. The BIOS in the chip and the BIOS backup file are identical according to windows' file compare. The revert, however, didnt work: the only thing the computer does is flash the power button 3 times when AC power is connected. I've tried unplugging the CMOS battery, holding the reset button and holding down the power button- no signs of life. Is there anything I can do?
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Hello Gurus,
I got a ThinkPad T480s. It was running fine but suddenly started random shut down. When it turned off, I had to push the reset pin to bring it back to life. But it got aggressively worse and became completely dead. No charging light, no life.
I did some initial diagnostics with just the board (no battery, nothing attached, and no CMOS battery as well)
Initial testing of the coil resistance seems to indicate no dead short. The only low resistance I measured was at PL701. It reads 38 ohms.
charger gave - 20V - ok
U101B
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Hello, I'm stuck in troubleshooting…
The flash system works like that : when the (mechanic) flash button is pressed, the flash mecanically pop up, and a circuit buck boost elevate 7v (batt) to 200-300v (?) for charging the big capacitor. And when the photo shoot button is pressed, the capacitor is discharged in the xeon light.
In the D800, there is a first « power board » close to the battery. 2 wires (batt 7v) goes to another little « flash board ». I measured 7v, so ok.
When I press the flash button, it's detected by the system, flash icon appear on LDC display.... -
Hello,
I am trying to repair a Dahua NVR4216-4KS2 that is not booting.
The main BIOS/firmware is stored in an SPI flash EEPROM (Winbond 25Q128, labeled as U130 on the PCB).
I have a CH341A programmer and I already attempted the following steps:- Identified the correct chip (W25Q128, 3.3V SPI flash).
- Tried to read the contents with CH341A Programmer software. The dump seems corrupted and I often get the error: “Chip with the contents are in disagreement.”
- Compared several chip type selections (24Cxx and 25Qxx families) to confirm it is indeed a 25 series SPI
08-19-2025, 09:23 AM -
Hi all,
I’m trying to recover a Lenovo Yoga Slim 7-14ARE05 with board DA0LS3MBAF0 Rev:F. I’ve run into an unusual issue where USB-C PD is stuck at 4.7–5V and the system won’t boot (keyboard lights flash briefly, then nothing).
🔥 The Problem Started After Suspected ESD/PD Fault
I experienced a power issue or ESD event through a USB-C charger
After that, the NX20P5090 power switch was visibly burned and was replaced
Now the PD controller always negotiates 5V @ 2A, even with known-good chargers
🧠 What I’ve Done So Far
Flashed... -
I'm able to read and write the chip by selecting a winbond IC of the same size, but when verifying it fails at around 25 percent.
I've modded the ch341a to 3.3v.
Can I update the database to include the XMC 25QH256C?
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