I have a set of JBL LSR25P speakers in which one had a popping noise about once every 2-3 seconds. A local tech (who only worked on pro equipment) bet without looking it was a bad cap. So I replaced all the caps and the problem persisted. The board has 3 LM3886 amp chips. 2 of them appear to be a push-pull setup and drive the woofer. The other one drives the tweeter. I powered it up and noticed that the LM3886 that ran the tweeter was extremely hot. The other two were room temperature. The datasheet stated that it has thermal overload protection and will shut down at a certain point and then restart. I figured that was what I was hearing. Being a novice I expected the chip was bad. I replaced it and powered up. The new Chinese chip exploded. So now I wonder if the tweeter was shorted and blew the cheap chip while the original could stand it. The tweeter appeared open now and I thought maybe the exploding chip drew enough to burn it out. So I got another chip and left the speakers disconnected. Turned on and the chip didn't blow but it quickly grew extremely hot again. Turned it off quick. I have verified the +-35volt supply at the chips. But I need help. I've attached the schematic and datasheet for the LM3886. Any guidance is appreciated.
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Re: JBL LSR25P amplifier chip overheating
Spray contact cleaner in those hf switches and look to see if you have DC going through those coupling caps between stages. Also if you have a scope look for for oscillation on that hf path -
Re: JBL LSR25P amplifier chip overheating
"The new Chinese chip exploded"
now its anyone's guess without knowing if the new ic is fake or not .Comment
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This is a guide that I am writing for helping others to replace their MEC1503 EC chip if it breaks (or to get around an inconvenient prompt to the BIOS). This forum has been extremely helpful to me so I would like to contribute to help others. I will tell you right now that this task is very difficult to do. You MUST have experience and tools to do precision micro-soldering, BGA reballing, trace repair, and general laptop repair skills.
There are some specialty tools needed to do this task. The replacement MEC1503 chips can be acquired from Aliexpress. Do not buy the bare chips as... -
Hi
I have a very strange issue with the BIOS SPI chip of an ASRock B650M PRO RS motherboard.
The SPI chip is an Winbond 25Q256JWEQ model (1V8).
The motherbaord doas not POST - it lits only CPU and DRAM EZ Debug Leds, and stays that way forever.
The Flashback function of the motherbaord is also not working, despite all instructions followed correctly - I'm 100% sure of this.
I have then desoldered the chip, backupped the contents, and tried to earease the chip in order to program stock image, but the chip is locked by status registers SREG2 (TB) and SREG6... -
Common SPI bios chip programming Questions and Answers
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Q: I have a bios request,i can`t post my backup as i can`t read from the chip.
A: If you can`t read from it how do you expect to write to it ?.
Q: Why is my bios chip unreadable ?.
A: The programmer is faulty or has a worn or broken zif socket.
The USB cable is frayed,connector pins worn or some other physical damage.
Not enough amperage or voltage to power the programmer properly.
Bad...09-02-2021, 04:40 PM -
Long story short:
- dad converted Asus Chromebox CN62 into Windows compatible, with mrchromebox BIOS, years and years ago
- gave the computer to his son a couple years later
- son now decided to revert it to Chrome OS, to sell it as original (re-writing BIOS with the backup one created by his dad)
- too lazy to remove the board from the case, thought a voltage regulator was the BIOS chip (you know... it has 8 legs)
(seems like the story was not that short)
He used alligator clips to read the chip. No luck reading it. Removed chip and placed on a SOC-8... -
Hello, anyone here have updated ezp2023+ chip database in .dat file format.
I need to add w25q256jveq chip but I do not know what data should I type.
I'm using the ezp chip dabase editor posted from here https://www.badcaps.net/forum/troubl...ro-programmers
The currenty unit model that I am trying to detect is HP elitebook 640 g9 which is currently locked on admin bios....11-25-2024, 12:53 AM
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