I have a power supply board to an PreSonus StudioLive 24.4.2 mixer that was brought to me for repair. The owner wants a single component that is visibly burned to be replaced. The marking for the component is labeled RT1. The circuit board part number is 400-PG2PWR . The problem is, I cannot locate any board schematics and the way the component burned, if there was any physical markings to identify it, they are long gone now due to the burning. The component in question is marked RT1 is 2 pin through-hole and is mounted vertically and round in shape. Color is dark grey or black....
grimacelord
Badcaps Veteran
Last Activity: 12-17-2025, 06:49 AM
Joined: 01-21-2017
Location: Atlanta, GA
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PreSonus StudioLive 24.4.2 Power Supply Board
Hello,
I have a power supply board to an PreSonus StudioLive 24.4.2 mixer that was brought to me for repair. The owner wants a single component that is visibly burned to be replaced. The marking for the component is labeled RT1. The circuit board part number is 400-PG2PWR . The problem is, I cannot locate any board schematics and the way the component burned, if there was any physical markings to identify it, they are long gone now due to the burning. The component in question is marked RT1 is 2 pin through-hole and is mounted vertically and round in shape. Color is dark grey or black.... -
Foscam C1 V2 IP Camera BIOS/Firmware Help
Hello,
I am not sure if someone can help me with this or not. I am hoping someone can.
I have a client who brought me a Foscam C1 V2 IP Camera after they disconnected power to the device during the middle of a firmware upgrade because they got impatient and thought it was frozen, so they disconnected the power despite a warning message telling them not to do that. Currently the device shows the power LED when connected to power, but it doesn't complete it's boot process and the camera is inaccessible on the network through Foscam's App for Android or the Windows application.... -
Just wanted to come back and report that a new battery finally fixed that last problem. The battery is now detected by the machine and all is well. So it was a combination of those two components on the logic board, the battery flex cable connector, a new battery, and a new battery flex cable. Everything works as expected now. As always, thanks for the help mon2! -
Back again with some new components from DigiKey installed. Some behavior is different, but still not quite right.
Components Replaced:
U5150 (RCLAMP3552T)
UD201 (LSF0102)
New Behavior:
With logic board fully installed, power adapter connected, but NO battery connected to logic board:
I2C_SMC_PWR_3V3_SCL: 3.25V
I2C_SMC_PWR_3V3_SCA: 3.25V
Taking same voltage measurement of the same lines WITH battery connected:
I2C_SMC_PWR_3V3_SCL: 0.607V
I2C_SMC_PWR_3V3_SCA: 0.76mV
Since I am now...Leave a comment:
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I know that this thread is old, but I found a solution to the black screen problem on this model.
I also had the problem of powering on by itself as soon as you connect power cord, black screen, or sometimes it would show a screen only once after a BIOS reflash, but never again.
After looking over the computer, the heatsink solution Acer used for this model is very poor. The heatsink has a thermal pad for the iGPU part of the CPU die which is insufficient.
Coupled with a very dusty fan, the computer's CPU/iGPU became damaged from overheating. Reflow CPU fixed...Leave a comment:
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Will do! I will order some today and let you know in a couple of days once I receive it. Thanks!...Leave a comment:
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The donor component is currently installed on the board. It was pulled from an identical board. I haven't yet purchased any components for this repair yet.
The datasheet can be found here...Leave a comment:
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Yes, UD201 was replaced with a donor from a donor board, but admittedly, the donor component may have been defective itself. I am not sure. Neither the original component nor the donor is working. I have already sourced a replacement at Digikey. Do you think it would make sense to buy new ones at this point?...Leave a comment:
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Both of those resistors read 6.7kohms, but the schematic says that they should be 4.7kohms. I checked my donor board and they read 6.7kohms on that board as well. A different thread I was reading on here from another user also reported his resistors to be 6.7kohms as well so I don't know if the schematic is correctly reporting the true value or not.
UD201: (The pins themselves are inaccessible under the chip, so I have to measure from nearby components)
Pin 3 (as measured by Pin 2 of RD200 next to it) - 1.25V
Pin 4 - (as measured by Pin 2 of RD201 next to it) - 1.25V...Leave a comment:
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In Ohms scale:
RD208 - (I2C_SMC_PWR_3V3_SCA) - OL
RD207 (I2C_SMC_PWR_3V3_SCL) - OL
If I switch the multimeter to Auto-Range, it reads:
RD208 - (I2C_SMC_PWR_3V3_SCA) - 4.55 MOhm
RD207 (I2C_SMC_PWR_3V3_SCL) - 4.44 MOhm...Leave a comment:
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Both resistors read 3.23V although they are not stable and fluctuate between 3.22-3.23V, barely a difference but I figured it might be worth pointing out. Either way, they're still not 3.3V, as they should be....Leave a comment:
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Our schematics seem to have components labeled differently from one another. Mine has different labeling than yours. See attachment.
Yes, BOTH components "UD___" are on the board....Leave a comment:
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Would the required pull-up resistors for these lines be RD207 and RD208? If so, both of those resistors read 6.7kohms, but the schematic says that they should be 4.7kohms. I checked my donor board and they read 6.7kohms on that board as well. Also, if those are the correct resistors, then to me, it looks like PP3V3_AON is the voltage rail for those resistors and I do have 3.3V on that rail.
So if all of that looks alright, could it be that UD201 and U5150 I pulled from the donor board may have also been faulty or would truly faulty UD201 and U5150 present itself differently from...Last edited by grimacelord; 07-25-2025, 02:18 PM.Leave a comment:
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Also, I tested for continuity from the test points on the logic board for both I2C_SMC_PWR_3V3_SDA and I2C_SMC_PWR_3V3_SDL to the battery side of the flex cable connector to make sure J5151 was soldered on well and the battery flex cable isn't broken and it's not. There is continuity.Leave a comment:
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Back again. Not quite fixed. Removing J5151 did indeed clear the short, but it hasn't fixed the problem of the computer not detecting the battery. I soldered a brand new J5151 connector onto the board, reassembled everything, and the computer still does not detect a battery and the fan spins high. I decided to measure the voltage this time and here is what I have:
I2C_SMC_PWR_3V3_SDA - 0.735V
I2C_SMC_PWR_3V3_SDL - 0.735V
PP3V3_AON - 3.3V
I did change UD201 and U5150 from a donor board, but it made no difference at all. I suppose they could have been bad components...Last edited by grimacelord; 07-25-2025, 10:03 AM.Leave a comment:
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Wow. That was it. The connector was the problem. As soon as I removed the connector J5151, the short cleared. Thanks for your help mon2. Solved.Leave a comment:
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The only other thing I can think of is the battery flex cable connector itself, J5151. I have removed all of the components on the I2C_SMC_PWR_3V3_SDA line that could be responsible for bringing it short to ground and the short is still there. The only component I haven't removed yet is J5151. Could that be the culprit? And if not, what else could it be? Internal short?...Leave a comment:
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I2C_SMC_PWR_3V3_SCL - (In Ohms scale on my multimeter) reads 0L. (if I set to auto-range - 13.53kohms)
I2C_SMC_PWR_3V3_SDA - 11.4 Ohms
Attached are pictures from the two areas as requested. Please disregard my flux stains that surrounds the area. I will clean that up later. I tried to cleanup the area you're interested in a bit with some isopropyl alcohol so what you're seeing surrounding the area is flux....Leave a comment:
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A2338 820-02020-A | Battery Not Detected/Random Reboots
Hello,
I have a A2338 MacBook Pro here that came to me because the battery wasn't being detected. The owner tried to replace the battery themselves thinking that the battery was the problem but the behavior continues even with their new aftermarket battery. They also accidentally ripped off the black plastic clasp to the battery flex cable connector @ J5151, but I pulled that off of a donor board and replaced that for them already. I did quickly check to see if that was simply the problem, but it's not.
First thing I checked was I2C_SMC_PWR_3V3_SCL and I2C_SMC_PWR_3V... -
Hello again,
I finally was able to give this another try, but unfortunately, I still have no POST.
I first flashed your files to each respective BIOS chip and then disconnected everything except for the essentials. Motherboard, CPU, a single stick of RAM in slot A2, and of course the power supply. I then cleared CMOS using the jumper on the motherboard, connected power, and powered on the computer and allowed it to try and POST for about 10 minutes the first time. Then, I shut down the computer, tried adding a GPU card and switched the HDMI cable to that, CMOS clear again,...Leave a comment:
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