what is this concept - VCLK (a pin namely "PWR_5V3D3V_VCLK" on 3v/5v IC) and for what purpose does it serve? any fellow can guide, the schematic page attached .,.,regards
Attached Files
-
-
Re: what is this concept - vclk?
It is better to study such cases from all angles. You did not post the details of from which this partial schematic was extracted.
1) Found the tab in your Adobe viewer screen grab.
2) You are reviewing the Latitude 3330 logic board.
3) Found the logic board schematic -> searched for VCLK -> the schematic you have posted is linked to the TI TPS51225. We are lucky that this TI part is available to the public so the datasheet is available.
4) Then search for the 'VCLK' label and found the full details on page # 14.
VCLK = output generated by the TI part and is a 260khz clock used for a charge pump voltage rail. Charge pumps are a low current boosting circuit to allow for a low voltage to create a higher voltage.
For example, on RS232 (aka serial port) transceiver chips, the Vin for the actual IC is +3v3 but they use CHARGE PUMP designs to double or triple the Vin to create a voltage swing of ~6v or even ~9v at the outputs of the transceivers. Being somewhat wimpy rails, they cannot supply too much current and often a few mA. The effort is based on the caps that act as the doubler or more for Vin relationship. Another example is the backlight power rail for LCD panels which takes in ~12v yet produces 25-50 volts for the output.
Ok to use for low current LEDs but do not expect it to power your cooling fan..
See attached.
PS: Next time, share more details so we can all save time in such reviews.Attached Files -
-
Re: what is this concept - vclk?
ok sir so nice and thank your for your concept clearanceComment
-
I have a Pioneer PDP-427XD TV, not many hours on it. Bought second hand, I think it must have been a TV used in a meeting room, as it was like new when we got it. No manual, but worked out most of it.
The Problem I have now is it went out with a crack noise, then a blinking LED, if I remember it had 6 flashes.
I had a look and after a bit of hunting around (very frustrating as TV shuts down after a few seconds), I found a Capacitor on the Scan Assy Top Board had cracked and tried its best to meld down. Now, as it happens, I can get to this capacitor, but not the others... -
This Concept 2 rower pm5 monitor doesn't shut down. It keeps turning on and stays on after being turned off. I read on another forum by another user that replaced the same component to check the voltage regulator.
The monitor should pull around 35mA when turned on and in shutdown it should drops to around 0.060mA. Any advice on finding the voltage regulator on this board to check if it needs to be replaced?
11-05-2024, 07:38 AM -
HI
I need good tested bios for acer concept d
GH67G LA-211P REV 1A 2021-03-17
CN516-72G-72SC -
This particular unit powers up, LEDs behave normally, but broadcasts no SSID, will not mesh with any other routers. Plugging in an ethernet cable from a Windows laptop results in "unidentified network" with an autoconfigured IP address and no response to pinging 192.168.1.1.
I was able to log into serial/UART by connecting the 6-pin header to the GPIO on a Raspberry Pi Zero W (GND to GND, TxD to RxD, RxD to TxD, no connection between +3.3V as it is supplied on both sides) using Minicom, command:
...Code:sudo minicom --baudrate 115200 --device /dev/ttyS0
-
TV: JVC LT-43C888 (purchased in 2018). This is a smart TV with Netflix, Youtube, Freeview and other applications via 'Viewd' app store
Problem with TV:
- Netflix stopped working so i tried to do factory reset from the TV menu.
- I confirmed on-screen but the factory reset did not happen even. It did not take me to 'first-time installation' screen as mentioned in the manual.
- After waiting for some time, the TV went into a boot loop.
- JVC logo comes on the screen and LED light flashes for some seconds, then it reboots again and the same thing happens
...
Comment