Looking for help to understand this problem a little more and what I should be testing for. Crown XLS2002 in bridged powering a Dayton dual voice coil UM18-22 18 inch driver in series at 4 ohms in a custom enclosure. Setup ran well for about 2 weeks then it didn't. The first driver when tested after the failure one coil was at 24 ohms and the other coil at 10 ohms but cone movement is smooth. Got 2nd driver and installed, it cooked right away. Coils ohm at 2 ohms each but the cone sounds crunchy. We believe that unfortunately it is the amp that caused this but I'm looking for advice on what I should be testing the amp for to confirm that the amp caused the failure. Any help is appreciated.
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hi all,
first of all: i'm a (motivated) newbie, so please forgive me any stupid question i may or may not ask
i'm currently repairing a projector: Epson EB-U42 that doesn't start (no lights, nothing).
what i've found so far:
- the PSU does its job and supplies 12V to the mainboard via the connector.
- shortly thereafter, there is a mosfet (TS420-600B) where i can test 12V on the one side (in the data sheet this side is called Anode), Gate 0V, Kathode shorted to ground
- not far away, there's the first cap with a resistance of 0.7 ohms.... -
In a Beelink GTR mini PC, mine has an Intel AX200NGW WLAN module.
Tried (only with keyboard/mouse connected):- BIOS + database update
- Using latest Windows 11 image built with official image creation tool
- Previous setup version for Windows 11 installer
- Replacing SSD without a slow block (the previous SSD had a slow block with access time > 500 mS)
- TPM reset (worked to the point where DRIVER_PNP_WATCHDOG error message is displayed briefly after the point of stalling)
- Disabling power to WLAN and LAN modules in BIOS (Advanced > AMD PBS > PCI Express Configuration)
06-19-2025, 04:59 PM -
I have 50 Chinese constant current isolated LED drivers based on LC6685 IC. 35 drivers are working fine, but there is a slight flickering in the rest of the drivers.
I have checked the output with oscilloscope and found that there is a slight random voltage fluctuation.
Is it possible to get the datasheet of LC6685 IC?
Also highly appreciate if you could let me know what could go wrong.... -
Hi.
picked up another TV. This time is a Vizio M65-C1. TV does not turn on. I had repaired another 60 inch vizio , Bad main board.
When power button is pressed, the Power led indicator on the bottom right, turns for a few seconds and then it fades away. No backlight or Vizio logo on screen. Removed back cover and repeated test.
This is the TV This TV is a little different from the Samsung I have worked on. Power supply is on the Left side, Main Bd is on the right side, T-CON , not in the picture is on the bottom. I am assuming that the boards in the middle are the LED... -
Hi,
Finally got time to fix this board up.
At first it didn't give any POST codes. Turns out it was an unsupported Celeron D cpu. After dropping in an Celery 2.6gHz the CPU came out of reset with clock signal, but still no post codes. For a while it did work when I applied pressure to the ADP3168 chip, but on next reboot the MOSFETs started to burn. Then I left it as is for months.
Now I came back prepared. Replaced the bad MOSFETs and the ADPxx18k drivers. Now I don't get any MOSFETs blowing up issues anymore. But sadly, the Vcore is missing. The whole VRM isn't...
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