hybridfree/eevblog-posts huggingface dataset:
X2 caps in RF controlled mains plug top adaptors dead, gone low value. - Page 1
Forum section: electronics / repair

author: Chris Wilson
author_rank: Super Contributor
timestamp: June 23, 2019, 11:57:19 am
content: I have common or garden RF controlled 13 Amp mains plug top adapters. Two have been left on powering low current devices for months and they have started to turn themselves off after some seconds or minutes. I stripped them down and the capacitive X2 mains dropper poly caps before the bridge rectifier and 5V regulator have changed value from 330nF to under 1nF. They are marked as MPX brand, which is a respected make, do these have a low finite life in such applications or are they likely fakes? I have ordered new Vishay ones from RS. This, from Googling, appears a common problem with these gizmos... Thanks.

author: SeanB
author_rank: Super Contributor
timestamp: June 26, 2019, 06:14:17 pm
content: Common fault, replace with better capacitors, and look in there for the series resistor, and up it's value to a larger value, like 1k 1W fusible. As well add a small 275V MOV after the resistor to neutral, to clamp the spikes that are killing the capacitor. Resistor increases mains supply impedance so a smaller MOV can clamp the spike and still absorb the energy that is applied. Capacitor will last a long time then.Done the same recently on the geyser timer, as the 330n capacitor had done the same thing. Was just a bit difficult to fit any thing other than the same brown metal film dipped capacitor in there, so soldered the MOV behind the PCB where there is a 2mm gap, and added a 2k2 1W fusible resistor externally to the power lead. also as a precaution changed the 470uF 50V capacitor that powers the 48V relay in it. Old OHL cap was at around 220uF and ESR was around 30R, bit high for a capacitor that purported to be "Low ESR", and rated to "105C". Used capacitors both times, again Sunday work. That ewaste pile comes in handy quite often.

author: floobydust
author_rank: Super Contributor
timestamp: June 26, 2019, 06:45:34 pm
content: Mains capacitive-droppers have high ripple currents and stress the capacitor, much more so if there are transients anything with fast dV/dt.Film capacitors in that use fail low value, the (stacked) sprayed metal end cap connections go bad. I'm not sure about wound constructions, it might be the self-healing mesh fuses open-circuiting. Another film cap failure mode is the metallization corrodes due to moisture, after years.Vishayspecifically mention some of their film caps arenotsuitable for series impedance applications, others only for X2 'across the line' use. They don't say why there is a difference.

author: Chris Wilson
author_rank: Super Contributor
timestamp: July 02, 2019, 11:08:22 am
content: Quote from: SeanB on June 26, 2019, 06:14:17 pmThanks yet again Sean, these are now working fine following your advice! I could have just bought some new ones but most probably they are all built to a minimum spec, plus I have learnt something in the process
X230T / X220T digitizer glass separation and cutting? - Page 1
Forum section: electronics / repair

author: idoit
author_rank: Contributor
timestamp: January 03, 2022, 06:50:22 am
content: Hey all, my second thread in eev. I hope this is the correct sub-forum.I have 2 questions:- I want to separate the digitizer glass from the plastic bezel of a tablet (Thinkpad X220T / X230T), without breaking the digitizer. There seems to be glue between plastic bezel and glass digitizer. Here is a photo and a little video to describe it better:https://imgur.com/gallery/Nc7olzzhttps://imgur.com/a/LxINJ04I was wondering if anyone has done a similar thing and if so, any recommendations etc.- Also, I want to make the glass a bit smaller up top. How difficult is it to cut the top part of the glass (where there is no digitizer) using a glass-cutter?Hopefully there may be other tablets/laptops that people have done similar thing, and if so, I'd like to hear your tips. Thank you!

author: flolic
author_rank: Frequent Contributor
timestamp: January 03, 2022, 07:50:49 am
content: I have no experience with that exact model, but heating the digitizer in the oven (at 70-80C) will soften the glue and make it to release much easier. We do this all the time with tablets and phones.Glass will probably shatter the very first moment you try to cut it.

author: idoit
author_rank: Contributor
timestamp: January 04, 2022, 01:55:34 pm
content: Thanks for your reply.1. Conventional kitchen oven, right? There is a flex circuit attached to the glass. Is it safe to put it to the oven with this?!!! (Please take a look at the image below. Discard the piece of tape behind it) If so, how long should I let it be in the oven?I know temperature rating for flat flexible cables (FFC) is 105 degrees Celsius, not sure about this flat circuit.2. For cutting, so there is no way of doing it? I need to make a cut at the red border shown in 2nd image below.

author: flolic
author_rank: Frequent Contributor
timestamp: January 04, 2022, 06:58:20 pm
content: Kitchen oven is fine as long as you keep the eye on the temperature. The goal is to heat the whole thing uniformly, I guess 10 minutes will be enough (but that depends of the exact oven).FFC will be ok, but try to not touch it at all while thing is hot to avoid tearing if off the glass.Use textile gloves to not burn yourself.About cutting the glass, I think you'll have to find yourself...
Xantrex 56-4 - Page 1
Forum section: electronics / repair

author: johansen
author_rank: Super Contributor
timestamp: April 10, 2025, 01:09:51 am
content: Friend of mine and i hooked up a 20kv power supply to the xantrex 56-4...Not realizing the output was isolated and when the 20kv started arcing through the esd mat to the table, the power supply internal relays started chattering and then the supply went dead.The fix may be as simple as a blown fuse, there are 3, 1/4W resistor sized 1 amp fuses and one of them (#55) was blown. I jumped it with a 4.7 ohm resistor with amp meter in series and the display came up, drawing .56 amps..so the pic is not dead.All of the other chips are standard parts however the main circuit boards are probably 4 layers.There is a mix of traces that are run very close to the power supply case, however there is a metal bar that runs directly over the top of the pic and spaced about 1cm away.Anyhow presuming it is dead.. whats a good replacement that doesnt cost $1400?
Xantrex MS2000 Charging Issues - Page 1
Forum section: electronics / repair

author: jerryk
author_rank: Regular Contributor
timestamp: January 27, 2019, 10:36:44 pm
content: I have a Xantrex MS2000 Inverter/Charger that was given me because of charging issues. I have gone through it and can't find any obvious faults with the following exception. The charging output has a significant ac component as shown in attached photo. The inverter output is a very clean sine wave. It's a difficult board to test since it has conformal coating on all of the boards and is three layered.I assume this is not normal for an Inverter/Charger like this to have such a dirty charging output, however it seems to be charging the batteries fine as far as I can tell.Any ideas on how to trouble shoot this problem?I added a photo of the component boards (less the two inverter boards) if this helps.Thanks - Jerry

author: jerryk
author_rank: Regular Contributor
timestamp: May 07, 2019, 04:49:02 pm
content: I'm finally at the point of finishing off this project. I think I got to the bottom of the charging complaint that caused a friend to will his inverter to me. He said it would not charge the batteries in his boat at all and went to fault. I managed to get it to fault only once and then the problem went away. There was a 1% sense resistor at the ac detect transformer that was off by 40% so I replaced it. So far I have ran it through all the trials I can think of in both the AC/Charge mode and the inverter mode without any fault codes or warnings being generated. I replaced most of the ceramic y-caps on the charger and ac filter board since I had it apart.But I still get that AC ripple in the photo above.It's about a 2V ripple at 60hz only in charge mode. This is measured at the main battery lugs on the inverter. Is this just normal on inverter/chargers like this? I ask this because in the mean time I did some repair/learning on a Magnasine 2810 that was flooded with salt water ( covered in a thread on Beginners Forum). The Magnasine now works fine other than it too has a fair bit of ripple (1V) on the charging output.So is this kind of ripple normal on inverter/chargers? Both have very large DC filter banks. The Xantrex MS2000 uses a separate DC filter board with 4 groups of 5 4700UF caps and the Magnasine MS2810 has four 6800UF caps in the middle of the FET board. In both cases the inverted AC looks like a very nice sine wave.If I never looked at the DC charging output on my oscilloscope I would be happy with the results. Am I worried for no good reason?Jerry
Xantrex Sorensen Ametek XG60-25 DC Power Supply. 1500W. 60V / 25A - Page 1
Forum section: electronics / repair

author: denis.b
author_rank: Newbie
timestamp: May 23, 2025, 07:22:39 pm
content: Buongiorno, sto riparando un alimentatore "Xantrex Sorensen Ametek XG60-25".Ho trovato e sostituito i due fusibili e i tre Power Mosfet come da foto allegata.Adesso ho la tensione e corrente regolabile ma funziona solo la prima parte dell'alimentatore, la seconda scheda per aumentare la corrente non parte.La scheda dove ho sostituito i Mosfet è alimentata ma non c'è segnale sul Gate del Mosfet e quindi nessuna uscita.Chiedo gentilmente se qualcuno abbia suggerimenti o uno schema elettrico di questi alimentatori XG 1500W da poter inviarmi.Grazie!

author: denis.b
author_rank: Newbie
timestamp: June 04, 2025, 03:54:21 pm
content: Good morning, I replaced the "TOP224YN" integrated circuit controlling the main switch and now it works.Unfortunately at startup I get an error message "err slau" that is overcome by holding down the adjustment button thus enabling the output voltage.What does that message mean and how can I clear it?The Amper display also detects 2-3A without any absorption…Thanks,Denis

author: m k
author_rank: Super Contributor
timestamp: June 05, 2025, 05:10:12 pm
content: Maybe it's defined as a SLAve Unit.
Xantrex / Sorensen XPD Switching PSU - Page 1
Forum section: electronics / repair

author: EHT
author_rank: Frequent Contributor
timestamp: December 01, 2021, 09:55:10 pm
content: I've got a faulty little Xantrex / Sorensen XPD 500W switching PSU. I wonder if anyone has found the schematic / service manual for the Xantrex XPD range or similar as I've only been able to find the user manual.I haven't started debugging it yet. Will post more info once I have time to start, would be great to have the schematicUnit is in good condition.Symptoms:- powers up, but whatever setting of the front panel V, A pots it stays reading 0.0 V, 0.0 A on the display. 0V measured at output. Remote programming and OVP not active- activating and trying the remote V programming, I notice that it briefly switches to current limit mode when applying a voltage control if the current control is set low. Still all 0.0 reading. Seems like it is trying to output but shorted.Anyone else tried fixing one of these?

author: EHT
author_rank: Frequent Contributor
timestamp: December 12, 2021, 08:43:23 pm
content: Oh well, luckily I fixed this one quite easily and it's in good condition so I'm happy with that. Quite compact and powerful.However, it is really hard to access. It has enough PCB area to be comfortably laid out in 19" 1U or 2U, but it's been rolled up into a 1/3 width case with 2 main PCBs, plus 2 daughter boards and a front panel PCB all jammed together so that you can't access it when powered up unless you were to make some extension cables. Even then it would be hard to disassemble fully to desolder components etc.Also, there's quite a lot to it... could be very hard to fault find without the schematic... so if anyone does come across the Service Manual / Schematic for Xantex / Sorensen switching PSUs, please share! There are a few multiturn trimmers that can be accessed externally to calibrate, so again service manual would be useful for that!
xbase09 tactile switches - Page 1
Forum section: electronics / repair

author: Scotto
author_rank: Newbie
timestamp: October 03, 2019, 03:51:44 am
content: Hi,Does anyone know where I could get replacement illuminated tactile switches like these for my xbase09?thanks

author: ataradov
author_rank: Super Contributor
timestamp: October 03, 2019, 04:26:46 am
content: They are all over eBay. Here is the first listing I found:https://www.ebay.com/itm/3pcs-12x12mm-Illuminated-Tact-Switch-Button-Switch-LED-4-pin-Reset-s261/142799314364Keywords for the search are "12x12mm" and "illuminated".
xbox 360 controller not working - Page 1
Forum section: electronics / repair

author: david smth
author_rank: Contributor
timestamp: October 24, 2024, 06:56:34 am
content: xbox 360 controller not workingGreen lights are not on, there is no voltage, I tried a lot, I cleaned it with isopropyl alcohol, I put in a new battery, the result is the same, it does not start, where should I look first, I cleaned it, there was a lot of corrosion.

author: bborisov567
author_rank: Regular Contributor
timestamp: October 24, 2024, 07:05:35 am
content: Check if any corroded pcb traces are present. They usually have darker spots or even look darker than the rest. Check if you have any corroded components, for example a chip pin can be missing.

author: david smth
author_rank: Contributor
timestamp: October 24, 2024, 11:27:30 am
content: these are the pictures

author: david smth
author_rank: Contributor
timestamp: October 24, 2024, 11:28:51 am
content: these are the pictures

author: stevopedia
author_rank: Contributor
timestamp: October 24, 2024, 03:24:58 pm
content: Do you have a multimeter handy? Try measuring for the battery output voltage where the batteries connect to the board. It's possible the corrosion on the terminals broke that connection.Try using a bit of dilute vinegar or citric acid on the areas that were corroded. Scrub the affected areas with a toothbrush until any bubbling you might see stops, and then rinse it with clean water. Any corrosion left over from your initial cleaning could spread, and even a thin layer can interfere with the batteries making good contact.

author: bborisov567
author_rank: Regular Contributor
timestamp: October 25, 2024, 05:18:42 am
content: I can see R27 missing from the board.

author: david smth
author_rank: Contributor
timestamp: October 25, 2024, 03:01:00 pm
content: Thank you, it was exactly like this when I opened it, it must have fallen off before, be careful, it goes directly to the chip, otherwise this part won't work, right?

author: david smth
author_rank: Contributor
timestamp: December 29, 2024, 05:30:52 pm
content: I tried everything but the xbox 360 control is not opening, the best thing is to replace it with another motherboard, there is no voltage, I connect the + cable directly to the + end of the diode, the chip is heating up, at least I understood that the parts on the edge of the chip are intact, the light is not on
Xbox 360 E USB Bypass Capacitor - Page 1
Forum section: electronics / repair

author: NicholsMatt
author_rank: Contributor
timestamp: February 01, 2021, 12:00:23 am
content: Hi all,I'm in the process of repairing a friend's Xbox 360 E. The unit wouldn't power on at all and some corrosion by the USB ports led my investigation there. I discovered that the 5 V and GND pins for the USB ports were shorted. I desoldered the (what I assume from googling is a 100 nF bypass cap) and the unit now powers on normally and the short had been removed.I assume I need to replace this capacitor. So my question is: any ideas on what an exact value might be or some best guesses as to the value? My DE-5000 says it's reading 1.5 pF but I'm not putting too much stock in that reading as I believe the cap is faulty, to begin with.I attached a mediocre image from my phone in case that can help provide any more helpful context/info.Thanks!Best,Matt

author: wraper
author_rank: Unknown
timestamp: February 01, 2021, 12:07:54 am
content: You can desolder capacitor from another USB port and measure it. IMHO it should be 4.7uF at least, If nearby electrolytic cap is used for USB, it may have lower capacitance though. In any case, value is not critical.

author: NicholsMatt
author_rank: Contributor
timestamp: February 01, 2021, 12:11:18 am
content: Good info, thanks. I have an SMD capacitor book on the way so I'll try a 4.7 uF (or similar). Thanks!
Xbox 360 Model: 1439 (Trinity) - without 3.3v and chip HANA with problem   - Page 1
Forum section: electronics / repair

author: GreatField
author_rank: Newbie
timestamp: October 15, 2025, 05:26:57 pm
content: I got an Xbox 360 Slim (model 1439) that had no 3.3V rail.I checked and found that the 3.3V line was shorted to ground, so I removed the filter coil and injected voltage into the 3.3V rail.The HANA chip started heating up.My question is:Can this HANA chip be replaced with one from another board, or is it paired ("married") to the specific motherboard it was originally soldered to?

author: Ismsanmar
author_rank: Regular Contributor
timestamp: October 15, 2025, 10:15:55 pm
content: Of course. It can be replaced for a new or used one. Usually they tend to fail when somebody "does something bad" with the HDMI port.https://xenonlibrary.com/wiki/HANAOn the 360 there is nothing paired. The only thing that is "paired" on a 360 is the CPU Key with the Key Vault.

author: GreatField
author_rank: Newbie
timestamp: October 16, 2025, 01:48:53 am
content: thanks, that xbox stop to work after a lightning strike.
XBOX 360 won't boot due to a solder bridge mishap - Page 1
Forum section: electronics / repair

author: einhander
author_rank: Contributor
timestamp: October 24, 2023, 07:36:57 am
content: hi guys , i have a question. Quite simply I soldered 2 points on one of my XBOX 360s. I check before moving on but this bridge escaped me.Anyway it will boot 1-2 times out of 10 attempts. I was wondering if I could probe with my DMM to find a component that is damaged.BTW........the Console works fine with its Retail NAND , but when I flash the Console to RGH 3.0 I have booting problems.I have attached an image if anyone is interested
Xbox One Original Powers on then off - Mosfets ok - Page 1
Forum section: electronics / repair

author: smurf786
author_rank: Newbie
timestamp: May 18, 2020, 06:42:00 pm
content: Hi Guys,I have a xbox one original console it powers on then straight off, please see vid:https://youtu.be/sKtBJYUd8SwI have checked mosfets and they seem to be ok, there was alot of dust in heatsink which i have cleaned out, applied new thermal paste to APU, changed the hard drive but still the same...Anyone know what i should be checking for or any other common problems i should look for...Thank you

author: Lin0
author_rank: Newbie
timestamp: September 03, 2020, 11:43:41 am
content: Wow no responses at all to the OP. I'm having same issue. Xbox One powering off after 3 seconds. Not the mosfets or the switch board that plugs into the motherboard. No shorted caps near HDMI...

author: fzabkar
author_rank: Super Contributor
timestamp: September 03, 2020, 06:21:15 pm
content: Locate all the coils and measure the resistance to ground. That should tell you which, if any, of the loads are shorted.
XBOX ONE Phat, VREG_CPUCORE variable - Page 1
Forum section: electronics / repair

author: whatboy
author_rank: Regular Contributor
timestamp: December 29, 2021, 04:42:21 pm
content: So I have two XBOX one phat, one that shuts down at intermitent times and one working fine, so I check the VREG_CPUCORE line and saw this!Then went to check the fully working one, and saw this too!!!voltage goes from 1.3v to 0v, why is that? seen that on laptops, but goes from 1.2v to .8v depending on what the CPU is doing, and only when windows starts... but 0volts???

author: Mario87
author_rank: Frequent Contributor
timestamp: December 31, 2021, 01:42:11 pm
content: Looks like it's using PWM to modulate the voltage, so if they want an average of 0.8V when the CPU is idling it will sit at 1.3V for 60% of the time and 0V for 40% of the time, giving an average of 0.8V, but I would expect that the voltage will be smoothed out as it gets closer to the CPU pins so by the time it gets there the signal is extremely smooth and clean.Not sure exactly where you took those readings from, but that's what it looks like.

author: whatboy
author_rank: Regular Contributor
timestamp: January 01, 2022, 05:20:06 am
content: It is not behind the coil, it is after the coil, actually it is on the capacitor... that is weird... and the xbox it is a working one.

author: Mario87
author_rank: Frequent Contributor
timestamp: January 01, 2022, 11:12:44 pm
content: Quote from: whatboy on January 01, 2022, 05:20:06 amWhich capacitor, how close to the CPU? CPU core voltage will pass through A LOT of decoupling capacitors near the actual CPU, if you are measuring this at the beginning of the voltage rail its not really weird as it will pass through various filter circuits to smooth out the PWM and decoupling caps to smooth out even more before it reaches the actual CPU.Unless you know where on the rail you are taking the measurement, you can't say it is weird or abnormal.

author: whatboy
author_rank: Regular Contributor
timestamp: January 02, 2022, 12:46:42 am
content: No, no, Every other line, like NB_CORE, GFX_CORE and MEM_CORE are smooth, only CPU_CORE has this weird beheavor!!!
xbox one s 3.3v stby voltage drops when front panel is plugged in.  - Page 1
Forum section: electronics / repair

author: haxorflakes
author_rank: Newbie
timestamp: May 15, 2024, 09:05:01 pm
content: since reflowing the 3.3v standby regulator chip, i now have my 3.3v, but when i go to plug in the front panel, it makes the output voltage drop down to about2.9 from the ~3.5 that it generates before plugging in the front panel. the added amperage draw that plugging in the front panel adds is ~20mA. for a measured total of ~60mA being consumed with power being injected onto the board.anyone have any ideas as to what to look for next to see why such a low amperage is causing it to drop the voltage?I have already checked the feedback circuit to make sure that it was getting the voltages fed back for what it is expecting. according to the datasheet, the minimum Vref voltage it expects is 598mV and when i have the front panel plugged in, it measured at 534mV. I dont think my issue lies with the feedback.I am unsure of what to check next.for reference the regulator chip is a monolithic nb671.

author: Harry_22
author_rank: Frequent Contributor
timestamp: May 16, 2024, 06:42:55 pm
content: Hello!Connect 51 Ohm load resistor to the output instead of front panel. Check the output voltage as well as input.
Xbox One S - Beep on, few seconds, Beep Off - Page 1
Forum section: electronics / repair

author: Chiefdm
author_rank: Newbie
timestamp: August 16, 2021, 02:15:18 pm
content: Hi all,First post here, I've done a quick search already and found a few helpful posts but nothing that can really give a definitive answer, so here I am.Bit of background, I know a bit about electronics (probably enough to be dangerous.... just) but I'm looking to start picking up board repair after 20 something years in IT. Thought I'd chuck myself in at the deep end and pick up a broken Xbox One S on eBay thinking that I would approach it as more of a "can I fix it" project rather than a "should I fix it" time saving exercise. I understand the generl layout on the board but obviously there are no schematics available for these things.So, on to the board. It has a stable 12V rail, and the mosfets on the 3 phases all seem to be ok. There are some fairly low resistance to ground readings (60ohms) around some of the memory rail components and a direct short on the V_CPUCORE test pointand extremely low RTG of 2.2 ohms on the NBCORE test point.What I have just noticed literally while typing this up and taking measurements is that there is a voltage regulator (this onehttps://www.onsemi.com/pdf/datasheet/cat6243-d.pdf) on the left hand side of the board measuring a direct short on Pin 2 which is the Vout pin which I'm thinking can't be good. I'm guessing that can only be caused by either that component going bad or the smoothing cap on that output going bad?Anyways, who want's to come down the rabbit hole with me to try and get this thing working??Any help/suggestions is/are very much appreciated!!

author: Chiefdm
author_rank: Newbie
timestamp: August 22, 2021, 07:58:30 am
content: Ok, bit more progress. I have now removed the northbridge chip using possibly the most ghetto rework setup ever…..! But it’s off and cleanjust need to find time to reball it now. Removing the chip has got rid of the short on the 3.3v rail though so I’m hopeful that once I get it back on that bit will be ok. Pics attached for those interested.On the flip side though I still have a short on the CPUCORE and GFXCORE rails…… looks like I might be breaking out the ghetto rework setup once more to try and remove the APU as well!
Xbox one s dead only 12v no 5v etc - Page 1
Forum section: electronics / repair

author: Dean3083
author_rank: Newbie
timestamp: September 29, 2023, 11:56:14 am
content: Hi everyone, having a bit of trouble finding the fault on a Xbox one s was hoping a standard shirt on the 12v line mosfets but nope all ok I checked what I believe is everything it came to me with a dodgy hdmi port removed that and the retimer chip I checked the voltage rails have 12v in and out but no 5v or 3.3 1.8 etc all dead. I checked the mp8757 I have 12v in and 5v on 2 of the pins and a 2v on en but no 5v output line removed coil to see if being shorted after but still nothing anyone else have any situation the same as me. I’m assuming without 5v I’m not going the get the other lower voltages.Tia dean

author: MathWizard
author_rank: Super Contributor
timestamp: September 29, 2023, 08:13:08 pm
content: Do you have an oscilloscope to see if the 5V tries to reach 5V ? IDK about consoles, but I'm guessing the start up on a routine, and when each stage is ok, it signal's the next stage to start up.Maybe it's that chiphttps://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MP8757/document_id/905Have a good look at the little circuit around it. They call the enable pin a digital pin, I see it mention 2V. But maybe there's a lot of noise on it too ?Maybe the output caps are going, and it can't raise the output enough, and shuts down ? Again a scope would be useful.

author: Dean3083
author_rank: Newbie
timestamp: October 30, 2023, 11:37:07 am
content: Hey sorry late reply life got in the way as always.I have diy mini oscilloscope I did a brief check and no 5v whatsoever I removed a few caps in case pulling to ground no change I have 5v on to other legs I sent to 5v out it was stable couple milliamps that in turn powered my 1.8v and 3.3 and finally the power button reacts. I’m going to assume I need a new mp8757 as also assuming my 2v engage is high enough.

author: tom66
author_rank: Super Contributor
timestamp: October 30, 2023, 12:06:17 pm
content: MP8757 requires at most 1.35V on the enable pin to turn on. You can find this figure in the datasheet:https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MP8757/under parameter "VILen" (page 4).So I agree with your conclusion, provided you have eliminated the possibility of a short circuit on the output side of MP8757. (Check with a multimeter across the caps for a short using the ohm setting.)
Xbox One S - no standby voltages anywhere - Page 1
Forum section: electronics / repair

author: Aimbit
author_rank: Newbie
timestamp: September 24, 2025, 03:59:57 am
content: Hi all, trying to figure this out but scratching my head.I have an XB1S that has no standby voltages. My first thought was to check the 5v step down IC at U4C3. I see 12v going in, and I saw 9.8v coming out of what I believe should be the 5v pin. I also get 2v on the enable pin.Ok so I have a parts board, took that same chip and swapped it (not 100% certain the parts chip was functional. I did a check before removing, I did not have 5v either, but I did have 3.3 and 1.8 )Anyhow to no one’s surprise, I still don’t have 5v, or any other standby voltages. Does the 3.3 and 1.8 require a functioning 5v? Trying to understand how I was getting those on my parts board but not reading 5v.Just for fun, I swapped the “bad” chip into my parts board to see if it read anything different. I got 9.8v again, but lost the remaining standby voltages.Do we think both chips are bad? I don’t seem to have any short on the 5v rail, or any other for that matter. Reading in the high mega ohms when checked to ground on the 5v. I don’t know if it matters but I was doing all these tests on the bare motherboard, no fan, power switch installed, etcThanks for any advice!
xbox one s rev G board known good voltages? - Page 1
Forum section: electronics / repair

author: derDragonmeister
author_rank: Newbie
timestamp: July 25, 2020, 01:27:53 am
content: as the title indicates i am in need of a list, or preferably boardview file, for an xbx1s revG. cpu, mem, NB, etc all have voltages, but TP4d4 and TP4D5 are showing 1.14v wich i find a bit odd since everything else is 1 or 1.5 or 1.8v i know there are chipsets that like 1.1v but without info on which it should be i am kinda lost. the system chimes and turns on but 2 seconds later beeps and turns off. lol so i have to keep one finger on the pwr button to msr all my rails.. any advice would be greatly appreciated, i cannot believe i have waited this long to join this wonderful community! thanks in advanced- Joe
Xbox One S - short on ram  - Page 1
Forum section: electronics / repair

author: damanloox
author_rank: Contributor
timestamp: June 24, 2022, 04:44:05 pm
content: Hi,I've an Xbox One S that turns on for a split second and powers off almost instantly. I have short to ground on all caps near ram chips (and it's a dead short. I know in "working" machine it's low resistance but on this one it's a short). I measured mosfets and they all seem to be OK, also measured 12V - no short there. I tried to inject voltage and the board takes about 1.5 amps at 1.8V but nothing seems to heat up (ie. ram chips slowly warm up but it's minimal and they all warm up exactly the same). I don't see any hotspots anywhere (note - I don't have a thermal camera, using IPA to see if it evaporates anywhere so my "diagnosis" may not be accurate).I inspected the board and there's no signs of liquid damage or any missing components etc.Went through several "tutorials" but they all seem to have faulty mosfets so not my case (I think)...Any ideas...?

author: james_s
author_rank: Super Contributor
timestamp: June 24, 2022, 05:39:39 pm
content: 1.5A at 1.8V is almost 3 watts, that energy must be going somewhere. It's possible the RAM is on the same rail as something else that is heatsinked though. My first thought was shorted decoupling capacitor, but I would expect that to hold the voltage at pretty close to zero.

author: damanloox
author_rank: Contributor
timestamp: June 24, 2022, 08:46:29 pm
content: yeah I know that energy must go somewhere... It's just that I don't see it(with my rather poor equipment). I'll try again and focus on the caps (worst case scenario I'll desolder them all...I was thinking that perhaps it's the apu - just wondering how much amps it needs to get warm to the point it starts evaporating the IPA.Also - (best case scenario/assumption) if one of the caps is bad - would that short _all_ other caps/ram (ie. are they all on the same rail)?

author: james_s
author_rank: Super Contributor
timestamp: June 24, 2022, 08:49:12 pm
content: Yes it will short anything that is on the same rail, although by passing as much current as you are, you should be able to see a pretty significant voltage drop as you get closer to the short so you might try that technique. Poke around with power connected and try to find the point where the voltage is lowest.
[Solved] xbox one s unable to generate 3.3v stby, bst mystery via help - Page 1
Forum section: electronics / repair

author: haxorflakes
author_rank: Newbie
timestamp: May 14, 2024, 04:38:39 am
content: there is a mysterious via that comes off of the 3.3v_stby chip that is not listed anywhere on the Schematics i have for it, and the chip is unable to generate a proper 3.3v on the bootstrap pin. i have removed the resistor R4C20 to see if there was something bringing the BST pin down, but i cant figure it out. there is no direct short to ground, and yet i am unable to get a proper bootstrap voltage coming off.with the resistor in place i was measuring .5v and with it missing i am getting 1v. the other curious thing, is when i try to measure from the pad of the resistor, i don't get any voltage except like 5mv, but measuring direct at the pin i get 1v. i did check for continuity between the pin and the resistor pad and i get continuity. so something is def weird there.anyone can help me determine where this via goes and why i am getting funky readings?Edit: Reflowing the chip has now made it generate the proper voltage
Xbox One X: caps values around the 3.3V test point? - Page 1
Forum section: electronics / repair

author: Slyken
author_rank: Newbie
timestamp: February 15, 2021, 06:20:12 pm
content: Hello, I'm trying to repair an Xbox One X that doesn't power at all.I found the TP10 "V_3P3STBY" is shorted to ground, the 5V test point close to it does show 5V.Here is a picture, please ignore how the caps look on the left, I tried to remove them with my hot air station and some flux:Does someone know the values of C267, C268, C274, C275, C284, C285, C289, C290, C299, C300 (I guess they are all the same) and C303 (the small one)?The caps on the left and right of the 56C215 chip are not shorted, and there is nothing on the other side, I hope it's one of them

author: fzabkar
author_rank: Super Contributor
timestamp: February 15, 2021, 08:52:57 pm
content: TI's datasheet recommends that the min/max values for Cout at 3.3V should be 88uF/500uF, respectively. For 10 caps, that's 8.8/50uF per cap.https://www.ti.com/lit/gpn/tps56c215

author: perieanuo
author_rank: Frequent Contributor
timestamp: February 16, 2021, 07:39:26 am
content: i quote myself from nother post:short on complex and relatively cheap pcb's cab be succesfuly diagnosed aplying the correct voltage from some variable power supply setting some current limit (like in your case i'll use 12V and minimum 2A), then your 'suspect' heats upthat method is tested in finding shorted capacitors in laptop motherboards, you find the broken one in seconds, can't beat this method (in some laptop mobo I used 10-20 amps to burn the capacitor, seems like a joke but works)look for some recent radio repair job here on this forum, i proposed this and some joker laught, but finally the OP used the method and found a broken transformer in 2 minutes. the thing, you can't broke what's already broken, and with this aproach you don't make more damage, maybe burn a track bu that's easy to fix afterwardsOR you can take out piece by piece, the visual check often fails short, after 2 hours
Xbox One X Power Supply Issue - Page 1
Forum section: electronics / repair

author: benscuba
author_rank: Newbie
timestamp: December 14, 2024, 10:06:53 pm
content: Hello,I have a dead power supply from an Xbox One X, No output at all.I'm not a electronic expert so i tried to open it carefully and test any voltage from caps to avoid dead shortI've look all the component i found i burnt one.I searched i foundhttps://www.eevblog.com/forum/repair/xbox-one-x-power-supply-repair/msg3028000/#msg3028000topic about the same faulty component but no reference about it to replace it.Did someone have any clue of the remplacement i can get?

author: Per Hansson
author_rank: Unknown
timestamp: December 15, 2024, 11:04:17 am
content: You can remove the common mode choke and just replace it with two jumper wires: that way you can test that the power supply works.If it does either find a scrap power supply to steal the common mode choke from (be sure it is rated for at least as much current as is shown on the label of the PSU, 2.75A in your case).Or buy a new one on Mouser / Digikey / Elfa / Whatever with a fitting footprinthttps://www.digikey.se/en/products/filter/common-mode-chokes/839?s=N4IgjCBcpgnATAZiqAxlAZgQwDYGcBTAGhAHsoBtcRAFiRpBLEQDYAGNhpxAVh9gDsjavwTDmA%2BCwAcIALokADgBcoIAMrKATgEsAdgHMQAX1NA
XBox One X PSU - Correct Voltage Output, Fails Under Load - Page 1
Forum section: electronics / repair

author: Dunderhead
author_rank: Newbie
timestamp: January 12, 2023, 03:48:14 pm
content: Have 2 of these power supplies now that make clicking noise (yeah I know switching power supply) and then crackling, almost static noise that cycles as soon as power is supplied. They are supposed to output 12v (and no other voltages) and they do. But they shut down when about 4amps is requested from them (rated for 20amps)Caps all look fine. No signs of burning around coil/chokes. Bridge rectifier putting out 165v dc. Just not sure what component would be likely suspect as , well, I'm a dunderhead.Attached mp3 that captures noises I'm referring to (it is top attachment and easy to miss now that I added pics). Also, known good power supply does not make these noises, is pretty much perfectly silent.Any insights greatly appreciated.....edit: For shts&giggles I did go ahead and swap out the two smaller output electrolytic capacitors (50v 47uf) just to see if any change. Just did because quick and easy. As expected no change. Also added photos of torn down power supply, cause hey, pics always fun. Burn mark in top view photo just from my solder iron trying to remove pesky shield. There were absolutely no burn or heat marks anywhere on supply.

author: Per Hansson
author_rank: Unknown
timestamp: January 12, 2023, 07:29:51 pm
content: You could use a plastic straw as a stethoscope to try to pinpoint where the noise comes from.But my bet would be on the 420v main bulk filtering capacitor, that it arcs over inside...

author: Dunderhead
author_rank: Newbie
timestamp: January 12, 2023, 10:22:48 pm
content: Thanks for the suggestions!....
Xeltek DOA-141 Universal Multi Tool - Page 1
Forum section: electronics / repair

author: EifX
author_rank: Contributor
timestamp: November 11, 2020, 10:04:28 pm
content: Hi there,I am looking for the schematics of a Xeltek DOA-141. It is a power supply 50V regulated and 5V and 15V normal, voltmeter, frequency meter, signal generator.The regulated 50 V power supply cuts off when a load is connected to it. I can't seem to find the part that causes the problem.Does any have the schematics or pointers how to locate the faulty part?

author: shakalnokturn
author_rank: Super Contributor
timestamp: November 13, 2020, 03:57:21 pm
content: Maybe it was DOA...A photo maybe? Google doesn't have much on the beast.Anything similar to the Voltcraft / Metex MS-9150?I think the schematic for that is around.

author: EifX
author_rank: Contributor
timestamp: January 20, 2021, 05:49:32 pm
content: Hello,Sorry for the very late reply...Here are some pictures.Hope someone can help me out.

author: EifX
author_rank: Contributor
timestamp: January 20, 2021, 05:50:17 pm
content: Bye the way no it's not the same. I think

author: shakalnokturn
author_rank: Super Contributor
timestamp: January 21, 2021, 11:40:55 am
content: Indeed different from the Metex.Should be similar to:Xaruba DOA-141Maxcom MX-9000 (MX-9003 also exists)I assume the OEM is: Dae Shin Electronics Co., Ltd.; Inc

author: Screwdriver
author_rank: Newbie
timestamp: January 27, 2021, 08:57:50 am
content: Good morning from Spain, here is the DOA scheme, I also have problems with the power supply. I have made some progress but cannot fully repair it. Please share your progress!

author: coromonadalix
author_rank: Super Contributor
timestamp: January 27, 2021, 11:18:25 am
content: @ screwdriver, is it the dc voltages ? have you checked all the dc voltages values ? there's a lot to check

author: Screwdriver
author_rank: Newbie
timestamp: January 27, 2021, 12:11:39 pm
content: Hi @coromonadalix, yes, there is a looooot to check. I think I have checked all the voltage values ​​and they are correct. I have very basic knowledge and there are parts of the scheme that I lose. At first, the variable PS dropped if you limited the current, when approaching 0. I replaced everything I could thinking that it is a device that is 30 years old (for example some capacitors), I also changed the lm324, and have changed or played with the power components. The result is that now it does not break when limiting the current, BUT now the PS provides 15v-60v, instead of 0v-50v. I'm honestly lost
XFX R9 380 No Ram Voltage. - Page 1
Forum section: electronics / repair

author: saronno
author_rank: Regular Contributor
timestamp: October 27, 2019, 06:47:14 pm
content: Hi, I am trying to repair this R9 380 by XFX.Fans works, no video .... but it's not the gpu ... there is no voltageon the ram.Looking at the board, there are two APW8722 near the two PCI-e power connector.Checking the datasheet, there are two interesting pins: BOOT and COMP.If COMP is pulled down, the IC shut down.The BOOT honestly I am not sure, but it should give a voltage bump atthe beginning to initiate the voltage regulation.VCC is presente. The two MOSFET connected to the IC are good.There are not evident shorts checking here and there with the multimeter .. and also checking with a finger if something is hot results in nothing obvious.Any idea? I was guessing the APW8722 was faulty but since both of them have the same behaviour I am inclined to think there is something else who stop them to regulated the voltage, maybe pulling down COMP ...At the beginning I also guessed there was something wrong with the bios but I check the chip with my ch341 and the bios was ok ... but there is no voltage to the chip when you star the board !!Photos of the board.https://imgur.com/a/Drf2g6L

author: saronno
author_rank: Regular Contributor
timestamp: October 30, 2019, 12:00:52 pm
content: Finally I have some spare time to keep analyzing this board.It seems the problem has nothing to do with the APW8722.I check the pci-e voltage and both of them are presente (12v and 3.3v).But GS7103 near the eprom has a very low VCC. So I find what componentis responsible for generating VCC .... and it's a adjustable voltage regulator (bm1117).But the Vin there is very low too.Anyway there are no low-impedence paths on the Vin and Vout line .... but nearby there is this little component who looks very suspicious.One pin is attached to bm1117 Vin the other one is attached to 12v line (present).Since the Vin should be more or less in that range (20v max) and Vout should be in the range 3.3v-5.0v (GS7103 VCC) I think think the problem is that little component ...it's a fuse or something else (it's not open and it's not short ....)Are you able to identify it?

author: saronno
author_rank: Regular Contributor
timestamp: October 30, 2019, 04:42:30 pm
content: This is from a rx470 ... same thing, more or less ...http://nekosoftpc.blogspot.com/2019/06/radeon-rx470-8g.htmlI replace the "the little component" with a 0 ohm resistor ... card is up and running.
XGecu T48 (TL866-3G) Self diagnosis error - Page 1
Forum section: electronics / repair

author: techrod
author_rank: Newbie
timestamp: March 25, 2023, 01:16:49 am
content: Hello, today is my first time using programmer since I didn't need it before.First I run software and it ask for firmware update and update complete successfullyAfter that I could never read SOP8 eeprom and tried a few dip and smd 25 seriesI ran the self test and it says ERRORVoltages shows 4.87V, 1.67V, 1.64V and 9.28V at one point it showed normal but 3.3V was somewhere in 2V and other voltages looked goodIts now never reached normal and so far haven't programmed a single device yet...On first check it gives red text there after just x or dashesWhat is the solution to this or did my programmer arrive defective?It also show firmware update greyed on GUI but i don't think necessary anymore since it was done before?Got it from seller on AliExpress:https://www.aliexpress.com/store/4805043so I'm sure its a reputable seller?Thank you for any help you can give me

author: jonpaul
author_rank: Super Contributor
timestamp: March 26, 2023, 01:18:00 am
content: NEVER "update" FW on 866 XGecu OR ANY ChiCom programmers, they can Rick the unit "invalid serial" etc.See the many old threads on 866 programmers.Jon

author: n4u
author_rank: Contributor
timestamp: March 26, 2023, 07:16:01 am
content: I bought mine t48 from that store and works fine (updates too). I thought its genique. Have you tried ask seller for support ? When you have issue with driver or software there should be issues with filmware upgrade.

author: giovannirat
author_rank: Regular Contributor
timestamp: March 26, 2023, 10:27:19 am
content: There is an information on the XGecu forum that they had a problem with an LDO AMS1117-adj chip.http://forums.xgecu.com/viewthread.php?tid=684&extra=page%3D1&page=2Most probably you have the same issue.

author: DavidKo
author_rank: Frequent Contributor
timestamp: March 27, 2023, 06:27:26 am
content: Quote from: techrod on March 25, 2023, 01:16:49 amFirst distributor in theirlist.@jonpaul SW update do the FW updates. Never had an issue with TL866 II.
XGecu T48 stopped working - self check hangs - Page 1
Forum section: electronics / repair

author: Mark Krass
author_rank: Contributor
timestamp: December 18, 2024, 02:34:20 pm
content: Hello guys,My 2-years old XGecu T48 suddenly stopped working. I went to Tools->System Self check, run it (no chip/adapter installed) and it hangs forever in the middle of the way - see screenshots.Updated firmware & Xgpro to latest 1.31 & 12.67 - no effect...Please avise?

author: MathWizard
author_rank: Super Contributor
timestamp: December 18, 2024, 03:17:25 pm
content: So does it always get stuck at the same point ? Does it complete uploaded the other firmware ? Maybe someone knows the order the self-check does stuff. If it was a programmed chip gone bad, I'd ask Xgecu if they would sell the programmed chip.I just got a new T48, and a little bit of something, is rolling around inside it. So I should open it up now, and see if there's a reset button or anything.I opened it up, and broke the warranty seal for nothing, whatever was loose, already fell out. I don't see any reset button, but there's a lot of chips and SOT-23 parts in there, and a big PSU section. If you're lucky, the problem isn't in any MCU/processor.

author: Mark Krass
author_rank: Contributor
timestamp: December 18, 2024, 04:10:42 pm
content: Yep, it gets stuck at the same point each time. Firmware update completes fine. So it looks like the problem not in central MCU but I don't have any idea how around 30-40% of the target's port buffers died with no reason. Last time when I used my T48 all went fine. My it be a power supply issue of these buffers?Do you know how self check is performed in T48 and what buffer chips are?Can Xgecu support stuff get any hand here?

author: Mark Krass
author_rank: Contributor
timestamp: December 18, 2024, 04:53:20 pm
content: Found the reason! Changed USB cable and self check went ok. No glue how it is associated. Hope it will help others who may encounter this problem.