hybridfree/eevblog-posts huggingface dataset:
PS3 fat delid like a Pro and fix YLOD caused by over heating - Page 1
Forum section: electronics / repair

author: dvd4me
author_rank: Regular Contributor
timestamp: June 20, 2022, 05:10:49 pm
content: This is a fat PS3 with YLOD issue.First cleaned and checked with the capacitor boost ( adding caps beside the Tokin ones) no success.This means the caps are not at the origin of the YLOD failure.Only thing left is to de-lid and enable additional pressure on the silicon die to try to fix the 1-st level interconnection.This is the only reason these units are failing with the YLOD because the heat affects the die connection to substrate.If the IHS ( integrated heat spreader ) loses heat efficiency, because of aged thermal paste between the die and IHS, then the high temperatures will affect the 1-st level connection. It's not PCB de-lamination, it's not that hot to get affected there.I believe almost everybody missed the 1-st level potential problems. It may be a bad batch of epoxy that is expanding too much and brakes the connections.Thus the necessity of pressing down directly on the die to compensate for the bad connection. This can only be done if you delid and remove all the support ( silicone or the white glue ) for the IHS to rest on the substrate instead of directly on the die.This is basically what I have done with 3 PS3 fat backwards compatible units.I do not have more fat PS3 to test but I am confident this is the way to restore those units.I have played hours with the one i first fixed and still boots up every time and no freezing during the games. The other ones are still booting fine even if I keep them off.Because of the liquid metal compound the temperatures are very good.You only need to have a thin film of that on the dye, no visible droplet.On the IHS the liquid metal is not even needed, since I could not spread-it because of surface being quite repellent, it did not stick. I left the IHS almost uncovered by any liquid metal compound.After all is assembled back, I put the hair drier in the back of the PS3 and let-it run for half hour.Hair drier is not capable of re-flowing, remember it's safe for your hair, it will not damage any PS3 component. Compare hair drier with the reflow station, that's intense heat and the board survives.The real reason the hair dryer "fix" actually works it's because it's concentrating the heating, thru the heat sink, directly to the die, and not necessarily to the solder balls to the PCB.Heating up is also good to expand and release any air pockets trapped in the liquid metal and heat sink compound.I did not wait to cool down, power on repeatedly until there was no more overheating shutdown, it just stayed ON !!!! Remember this was YLOD initially.That's it folks, keep repairing these wonderful units.Tools are from amazon, the excellent painting tools and the dollar store bubble liquid to make the tool slide like butter.
PS3 slim YLOD RLOD fix - Page 1
Forum section: electronics / repair

author: dvd4me
author_rank: Regular Contributor
timestamp: May 02, 2022, 08:02:25 pm
content: Hello,This is about fixing the PS3 slim red light of death, yellow light of death or any other light combinations while booting.I found this slim PS3 CECHK04 model in recycling, it was turning on with a high speed fan and red light blinking. It was opened and missing the cover screws.Never had a PS3 fat before so I had little info about the most common failure modes. It seems this red light blinking was a very common issue.I start reading about the trend of re-flow the chips, this made me more curious, now I know they were practically killing these machines by reflowing the chips, CPU and GPU.It seams that the heat treatment was reviving the TOKIN capacitors enough that the result of the re-flow was an almost " back to normal" PS3.Which it was, curiously, proven after that it does not last very long, because other complex reasons like PCB delamination issues and other scenarios.I believed initially the high rpm fan issue in this PS3 was caused by bad heat transfer, the dried thermal paste well known issue.Not realizing this is not the cause, I tried to fix-it, I de-lid the CPU and the GPU to replace the thermal paste. There are some decent guides out there for that.Obviously this has done nothing, still high rpm. Then I did the hair dryer " fix", warming up the CPU/GPU to a decent temperature.You have to understand that any hair dryer will not be able to re-flow the CPU and GPU and solve any issues. I was just curious to see the effect on my PS3.In my case, heating up the TOKIN's capacitors just made the fan go quiet! That means the CPU just booted up and realized there was no overheat after all.Further testing, when it was about to show an image thru the HDMI port, the red light starts to blink. That means the GPU is not going anywhere.This is the point I started to search deeper and I found this TOKIN capacitors issue, I tried changing them with regular electrolytic caps and it worked! The PS3 booted.After that, all it was just a question of soldering skills and all is good now.Here is the video of the fixing and PS3 booting up:The picture below is the new arrangement of the replaced TOKIN capacitors.

author: dvd4me
author_rank: Regular Contributor
timestamp: June 20, 2022, 04:43:50 pm
content: Hello again,This is the second part where the Blue ray drive is put back together after it was harshly opened by the previous owner to extract the disk stuck inside.Since the PS3 was still running nice after the caps were changed I wanted to be able to insert the game discs.Temperatures after delid and liquid metal compound were very good and the fan was quiet.Video of the Blue ray drive is here:Cheers
PS3 Slim Power Supply - Page 1
Forum section: electronics / repair

author: ed-209
author_rank: Newbie
timestamp: October 03, 2021, 02:02:52 pm
content: Afternoon AllHelp NeededTrying to identify the capacitor that has blown on my PS3 slimPlease see attachedAll Help WelcomeThanks in advance

author: paul_g_787
author_rank: Frequent Contributor
timestamp: December 26, 2021, 01:32:42 am
content: Well all I can see from that photo is that it is a film capacitor.They usually have the voltage and capacitance written on them in printed text. Sometimes it is hard to see so I would suggest de-soldering it and having a look in a good light.Make sure to discharge it first.Also that resistor nearby looks a bit crusty. Would suggest measuring it.It may just be blackened from the capacitor and actually be fine but best to check it.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: December 27, 2021, 11:00:13 pm
content: Metalized polypropylene film capacitormost has no unit marked e.g. only 683 means 68 . 10^3 pf i.e. 68 nFjust ask seller the same size so can estimate approximately the rating
PS4 Dualshock 4 v1 Stick Drift - Even After New Sticks? - Page 1
Forum section: electronics / repair

author: paul_g_787
author_rank: Frequent Contributor
timestamp: November 30, 2021, 04:05:42 pm
content: I have just recently learned to hot air solder and have been repairing tons of PS4 controllers by replacing the analogue sticks.However I have one controller here which like all the countless others is suffering from "Stick Drift" it is the v1 Controller model JDM-011Now I just installed two brand new full sticks onto it but the drift is still there on the right stick!I just removed and changed the right stick for a second brand new one but the issue persists!!I have verified this on my PC using jstest and as you can see the right stick vertical axis is reading a value of 3040 without any input.Any ideas? I am stumped.Edit: I would like to add that this was the same reading the old original stick was getting.
PS4 PRO ADP300CR only works in 220V - Page 1
Forum section: electronics / repair

author: rvalente
author_rank: Frequent Contributor
timestamp: August 25, 2020, 10:22:45 pm
content: Hello Mates,a friend of mine asked for help, fix their PS4 PRO power sypply. The damn thing will only work when plugged in 220V, not in 110V.I believe is the 5V stand-by power supply doing funny business.The model is ADP300CR from delta, seems very well built (even some nippon chemicon as main caps)The controller is a remarked SOIC16, DNP012.Could not find any help online.Any suggestions?

author: wraper
author_rank: Unknown
timestamp: August 25, 2020, 10:29:38 pm
content: I think it might be dead PFC. If it's not running, it simply passes mains voltage through without any boosting. During full operation (not standby), voltage on 450V electrolytic capacitors should be around 400V, if it's much lower, PFC not running.

author: rvalente
author_rank: Frequent Contributor
timestamp: August 25, 2020, 11:28:14 pm
content: I believe the PFC won't run while the power supply if off, but i do not know how to turn this baby on, maybe some short or feeding 5V back in the 4 way connector.My friend just handed me the PSU not the console itselft.Anyway, is a good tip.

author: wraper
author_rank: Unknown
timestamp: August 25, 2020, 11:40:12 pm
content: I don't know which pin you need to pull up or down. But you also need some load attached to PSU. Without any load at all PFC most likely will not work properly and will shut down due to overvoltage protection.
PS4 Pro rear USB 3.0 replacement - Page 1
Forum section: electronics / repair

author: SYN80
author_rank: Newbie
timestamp: November 19, 2019, 03:41:29 am
content: I'm trying to replace the non-functioning rear USB 3.0 port on my Playstation 4 Pro and the only ports I can find do not 100% match the original port. The original port has 4 anchor points and the ports I'm finding on ebay are only 2 anchor points. It looks like it may be possible to use one and it be as simple as dropping it in and soldering the points. Does anyone have advice in this situation before I proceed with attempting this fix? Thank you for timeI have included pics below.

author: tooki
author_rank: Super Contributor
timestamp: November 19, 2019, 12:27:28 pm
content: Quote from: SYN80 on November 19, 2019, 03:41:29 amStop wasting time with eBay and instead look at a real distributor like Digi-Key. There are too many variations to rely on what happens to be on eBay at any given moment. There are differences in mounting, pin positions, height, orientation, etc. (For example, on the PCB shown, the rear anchors are next to the pins, while on the eBay one, the anchors are forward of the pins, meaning that it wouldn’t fit at all.)Without having any kind of dimensions to go on, it looks like it could be a Molex connector. Take a look athttps://www.digikey.com/en/datasheets/molexllc/molex-llc9876510181Here’s a link to the search results for through-hole receptacles:https://www.digikey.com/short/pvc8dv

author: SYN80
author_rank: Newbie
timestamp: November 19, 2019, 06:41:43 pm
content: Thank you for the information and links. I may just have to remove the original from the board and look to see if it matches up with those in the link.

author: maginnovision
author_rank: Super Contributor
timestamp: November 19, 2019, 07:29:17 pm
content: Also realize the PCB is very heavy and used lead free solder so desoldering wont be easy and you'll need a good iron to attempt to solder it.

author: SYN80
author_rank: Newbie
timestamp: November 19, 2019, 07:59:31 pm
content: I plan on using flux with a hot-air tool. After watching videos of HDMI port replacements on PS4, the USB port seems like it should be much easier since all contact points are on 1 side of the board.

author: maginnovision
author_rank: Super Contributor
timestamp: November 20, 2019, 12:34:29 am
content: I'm pretty sure last time I did one it was all through hole, but maybe I'm misremembering.
Ps64e8000 powersupply troubleshoot - Page 1
Forum section: electronics / repair

author: ant17
author_rank: Regular Contributor
timestamp: October 04, 2022, 05:33:13 am
content: hi i have bn44-00516a power supply out of a samsung ps64e8000 tv which transistor failures in the pfc circuit and the main switchmode supply ic failed taking some tracks with them and the tv has some missing smd caps which i do not know the value of cx814 and cx812 cx813and the smd cap cx826 which goes the across the switchmode ic is missing also but i need to know where the track that runs between it goes as it has partialiy missing peice where the red line is the track under cap to either one of those pins seen in the picture can anyone help
AGILENT PSA E4440A – 1st lo Unlevel error at 16.91 GHz (Band 3) - Page 1
Forum section: electronics / repair

author: Mgelderland
author_rank: Newbie
timestamp: October 05, 2025, 05:25:42 pm
content: Hi all,I’m troubleshooting a PSA (E4440A/E4443A/E4445A) and I’m stuck with an issue around the SLODA (A21) / ALC control loop.Symptom:• At 16.91 GHz (Band 3) I consistently get an Unlevel error.• RF path itself looks fine: on a spectrum analyzer the Sampler Out from 16.8 to 17 GHz is flat and clean, no dip at 16.91 GHz.• Signial from A18 YTO looks normal and wright amplitudeMeasurements so far:• Sampler Out: −4.4 dBm @16.8 GHz, −6.5 dBm @17 GHz → within spec (−8 to −3 dBm).• High Band LO out: 13.6 dBm @14 -+3 dBm• Low Band LO out: 13.5 dBm @14.5-+1dBm• 1st lo out at 5ghz zero span 15 dBm at 16.91ghz 18dBm• When I turn the preselector off no error and level 13dBm• EXT SENSE: drops to 0.0 V during the fault, measured both on the SLODA and at A13 → so not just a cable/connector issue.• INT SENSE: only small change (−218 mV → −211 mV). ( Band 3/4)• Band 0 -208mv (value on the A21 sticker)• Band 1 -218mv• Band 2 -165mv• Band 3/4 -218• Level Adj: normally around −0.6 V, but jumps to +0.05 V right at 16.91 GHz (outside the expected −0.5 to −3 V range).• Gate Bias: label value −106 mV, measured around −0.50 V (shifts to −0.42 V at the fault).Interpretation:• RF distribution itself seems fine (Sampler and LO outputs present).• The issue appears to be in the ALC/levelling loop: Level Adj goes the wrong way, Gate Bias is off, and EXT SENSE is pulled to 0 V.• Likely suspects: A13 Front End Driver (provides ALC drive, Gate Bias, and EXT/INT mux) or the SLODA itself (detector/leveling circuit)Has anyone run into this specific behavior (Unlevel around 16.91 GHz, but sampler output still clean)? In your cases, was the root cause more often the A13 Front End Driver or the SLODA board?As I mentions when I turn preselecter off its follows (option 123) and no 1st unlevel errorThanks in advance!
PSA parallel pliers are amazing for connectors - Page 1
Forum section: electronics / repair

author: ivan747
author_rank: Super Contributor
timestamp: June 20, 2025, 07:15:05 pm
content: Just the title. Parallel pliers are amazing for removing rectangular connectors. They just grab. You can grip with plenty of force and they will not slide out and pinch your wires.

author: jdragoset
author_rank: Frequent Contributor
timestamp: June 20, 2025, 10:10:22 pm
content: I have a cylindrical one that works wonders on bent BNC barrels

author: thm_w
author_rank: Super Contributor
timestamp: June 21, 2025, 01:12:16 am
content: Photo of what you are using?This is more appropriate for:https://www.eevblog.com/forum/reviews/
PSA question with ERR reading I2C EEPROM on RF_ATT_CTRL board - Page 1
Forum section: electronics / repair

author: allenw
author_rank: Newbie
timestamp: November 16, 2023, 09:27:38 am
content: Hi,I have the R&S`s PSA( model number FSEB30 ) part number is FSEB30, now turn on power and into system, it has a error in "system message". and the error message is "ERR reading I2C EEPROM on RF_ATT_CTRL board" as the attachment.who know which board is the function of the RF_ATT_CTRL board and this I2C EEPROM IC inside it?thanks!Allen
PSP 3000 ta-090 ripped off d-pad connector - Page 1
Forum section: electronics / repair

author: SotirisGR
author_rank: Newbie
timestamp: January 28, 2024, 06:06:48 pm
content: Hello everyone! I'm trying to resurrect a psp 3000 (ta-090 motherboard), the dpad and power supply connector were ripped but i managed to find the power supply connector. On the other hand i'm having trouble with dpad, it's a 0.5mm pitch zif connector. I can't find the exact locking type, could you help me pointing me some sources where i can buy the replacement or the terminology for this connector?Image
PSPH531801A plasma power supply - Page 1
Forum section: electronics / repair

author: chema.rb
author_rank: Contributor
timestamp: July 03, 2020, 05:50:03 pm
content: Hi!I'm trying to repair a PSPH531801A plasma power supply. I have 5V standby, but nothing happens when connecting PS-ON to ground (through a current limiting resistor), or VS-ON to 5V.Do you know if the diagrams are available for this model? Or maybe someone has an idea on where to continue troubleshooting?
PSU Earth Ground/Neg.  - Page 1
Forum section: electronics / repair

author: BILLPOD
author_rank: Frequent Contributor
timestamp: September 17, 2021, 07:21:14 pm
content: Good Morning All, I've had a Dr. Meter DC bench power supply for a few years now, (model # PS-305DM) and just discovered that the negative banana jack is internally connected to the earth ground banana jack, (which is connected to my mains earth ground). I can't believe I haven't blown something upwhile probing devices with my scope, (devices I'm powering with the PSU.I'm going to tear into the PSU to disconnect my neg from earth GND, but I'm wondering if any of you have resolved this issue and can point me to where this connection is, inside this PSU. Thank you in advance.

author: J-R
author_rank: Super Contributor
timestamp: November 11, 2021, 05:56:44 am
content: I have the same power supply but mine has an external flat bar connection between the negative and ground posts. Without it I measure about 20MOhms between the two terminals. So hopefully it could be a simple internal modification. Have you taken a look inside yet?

author: bdunham7
author_rank: Super Contributor
timestamp: November 11, 2021, 06:04:58 am
content: I had a similar issue with a power supply that used tantalum capacitors as EMI filters or whatever from all the floating grounds to earth ground. One of them shorted. You probably just need to take it apart and you may find something like that or something physical that has connected.
PSU RLU 01-60 / 5 - Page 1
Forum section: electronics / repair

author: frantisek
author_rank: Regular Contributor
timestamp: August 10, 2019, 05:39:07 pm
content: Greetings! Does anyone have any schematic for Slovenian source RLU 01-60 / 5? It is a 60V and 5A power supply. The current limiter is lit even without a connected load.
PSU Short Circuit Protection prevents me to find short, disable ?? - Page 1
Forum section: electronics / repair

author: cpuxxx
author_rank: Newbie
timestamp: January 13, 2020, 07:56:09 am
content: i bought 30v, 5 amp power supply. I see in youtube videos people junction power to power rail to find which chips or components shorted. When you give some power to rail, the components which have problem start heating up so they understand component is shorted and must be removed. My power supply has Short Circuit Protection feature and when i junction power to see which components would heat up and shows me but Short Circuit Protection prevent it and cut power off power supply. So should i disable Short Circuit Protection or anything else to do ?

author: trevatxtal
author_rank: Contributor
timestamp: January 13, 2020, 08:28:16 am
content: It is not wise to trace shorted faults by using power and hope to find a hot spot ,The reason is if it is a true short you will find the tracks and any other parts in line will heat up and possible burn making things worst.The way to trace it is to use a ohm meter and isolate areas by cutting connections and or tracks.That is after a good visual inspection of the components and tracks to see if any clues are there.Any capacitors that are out of shape take them out !Trev

author: shakalnokturn
author_rank: Super Contributor
timestamp: January 13, 2020, 12:22:50 pm
content: Quote from: trevatxtal on January 13, 2020, 08:28:16 amIndeed, the "high power" method could have some unexpected / unwanted outcomes.A better approach and big time saver would be feeding the output with limited power, keeping voltage and current to levels where they are unlikely to do more damage, then shooting it with a thermal cam.
PTC replacement in 28w T5 ballast - value? - Page 1
Forum section: electronics / repair

author: cape zoloh
author_rank: Contributor
timestamp: July 16, 2022, 03:43:28 pm
content: The PTC blew in a 28w T5 ballast and I need to replace it.Problem is, there is no component left to measure, as it exploded.Anyone with knowledge of what type of PTC I need to get?The ohmage of these varies quite a lot.I understand that a sufficient voltage rating is needed, but the rest is unknown to me.

author: Kleinstein
author_rank: Super Contributor
timestamp: July 16, 2022, 06:06:46 pm
content: A first question is if one really needs the ballast or would change to LED light in short time anyway.A PTC may make sense as a kind of fuse - if blown, chances are that there are more problems. For a replacement one would look for a suitable PTC fuse for the expected current.However the part may also be a NTC for inrush current limiting. Ideally the NTC you can buy have a datasheet to tell the right one for the size of filter capacitor and expected inrush current.Similar to the PTC case there is a chance that there are more defects. So a replacement NTC/PTC may well blow again in relatively short time.

author: cape zoloh
author_rank: Contributor
timestamp: July 16, 2022, 09:59:04 pm
content: I'm well aware changing a fuse might change nothing, but as this lighting fixture have worked for years I'm willing to try, but getting a correct PTC seems very hard without more knowledge. A 28W T5 tube is a known current. Maybe I'll try one of those Vishay PTCL I think the series is called.Might be right regarding LEDs. However this is my parents designer lightfixture, and they will never let it go...maybe I can modify it...
PTS 160 TCXO distorted sine wave output - Page 1
Forum section: electronics / repair

author: wd5jfr
author_rank: Regular Contributor
timestamp: January 15, 2024, 09:46:12 pm
content: This PTS 160 (160 MHz synthesized freq gen) is intermittent and I think it's due to the 10 MHz TCXO output. Sometimes I get a nice smooth output and other times it's distorted and later dies. I thought it might be my scope or probe but another scope and probe show the same. I kind of remember seeing a similar waveform on my Collins R389 PTO output. I can't see the label on the TCXO can since it's right against the side panel. Any ideas on the cause of this distortion?Thanks Hank

author: wd5jfr
author_rank: Regular Contributor
timestamp: January 16, 2024, 10:25:54 pm
content: Anyone know what kind of simple circuit would output such a distorted wave from a symmetrical sine wave?
PTZ ip camera troubles - Page 1
Forum section: electronics / repair

author: BellaminoBoy
author_rank: Newbie
timestamp: September 16, 2020, 12:21:41 pm
content: I have a strange problem with a generic IP Wi-Fi PTZ camera. The camera is located on a horse stall, powered from 4S40P Li-Ion pack charged by MPPT and 240 W solar panel. The thing s installed a switch on my solar distribution box to turn off the camera on low sunlight, rainy days so it does not discharge my battery (i need it also for light, door openers, fence energizer etc...). Just a simple push rocker switch, nothing special (planned to replace by a adjustable low voltage cut off module, just did not have time to make one yet).I noticed PTZ function stopped working immediately and camera draws 2.5 A instead of 900 mA as usually. After few trips to the roof, taking down the camera i noticed it worked every time in my lab, but not on my stall roof. Then i realized if i remove switch and hard-wire the camera, it works perfectly. As soon i put the switch back, camera PTZ function stops working and current draw goes from 900 mA to 2.5A. I can view the image online, but can't move the camera or zoom. Also, when wired to switch camera does not perform its reset, moving in all directions when power is applied. If hard-wired it will normally move in all directions and center. So ok, maybe the switch is defective, having some abnormal resistance. I put a new switch, same. I put three types of other new switches, same happens. I put a new relay instead of switch, same. I tried measuring resistance of switches, the resistance is so low i even dont have equipment to measure it.I have been troubling this problem for some days and cant find out what could be the issue. It is almost mistical problem, that i cannot believe myself.

author: Renate
author_rank: Super Contributor
timestamp: September 18, 2020, 11:31:40 pm
content: It sounds like it's trying to home but stays stalled.The root cause could even be something mechanical.You need to monitor the voltage directly at the camera.
Pulled this from an Amprobe meter today. - Page 1
Forum section: electronics / repair

author: mendip_discovery
author_rank: Super Contributor
timestamp: October 24, 2022, 07:08:16 pm
content: This is the worst I have seen.

author: Gyro
author_rank: Super Contributor
timestamp: October 24, 2022, 07:49:29 pm
content: I suppose you can be grateful that it didn't leak at the connector end!

author: mendip_discovery
author_rank: Super Contributor
timestamp: October 24, 2022, 08:21:50 pm
content: It's an Amprobe meter, so I suspect it will be an improvement if it did leak all over the inside.
Pure Evoke H4 Not Powering Up - Damaged Component? - Page 1
Forum section: electronics / repair

author: Grotsoft
author_rank: Newbie
timestamp: January 30, 2021, 12:19:05 pm
content: Hi,I'm looking to repair a Pure Evoke H4 DAB radio.Nothing's happening on power up, the battery is showing 3.9V but, again, nothing happens when trying to power up from it either.It looks like my SO pulgged in a 21V PSU rather than 12V PSU at some point.Physical examination of the board shows what looks like a damaged (diode?) tied to one of the battery input pins. I've attached a picture of the component, it's the black rectangle at the top of the picture.My question is:1. Is this a diode? (It has two parallel lines at one end.)2. Does anyone have a circuit diagram of this radio? I've had a look through dozens of sites.thanksStewart

author: Manul
author_rank: Super Contributor
timestamp: January 30, 2021, 12:42:56 pm
content: It is likely a diode (could be also a zenner diode), thats true. Does it look damaged? It is not clear from the picture. It could be more then one damaged component, don't forget that. Do you own a multimeter? Soldering station/iron?

author: Grotsoft
author_rank: Newbie
timestamp: January 30, 2021, 01:00:25 pm
content: Quote from: Manul on January 30, 2021, 12:42:56 pmIt does look damaged, you can see what looks like some bulging on the top.I have a full set of electronic tools, just not much experience with surface mount components (valves and MCUs are more my thing).I used the diode test mode of my multimeter on that component (in situ) and got 0.5V one way and 0.6V the other.

author: Manul
author_rank: Super Contributor
timestamp: January 30, 2021, 01:37:42 pm
content: In that case it is most likely good. Overstressed diode will usually fail shorted. Bulging to me looks like residue of some glue / conformal coating. Proceed with tracing and measuring power path and power rails of the circuit, switching converters, linear regulators, etc. Is some rail shorted?

author: Grotsoft
author_rank: Newbie
timestamp: January 31, 2021, 10:08:57 am
content: Thanks Manul, I'll dig in.
Puritan Bennett Renaissance II  - Page 1
Forum section: electronics / repair

author: rcarlton
author_rank: Contributor
timestamp: November 03, 2019, 10:44:33 pm
content: I have an old Puritan Bennett Renaissance II spirometer dating to 2003. The company has changed hands a few times and is owned by Medtronics. No luck with their support. The item was working recently, now I get an error code 113 resource corrupt after a long wait while the unit was recovering data. The plastic tabs that hold the screen in place were broken, other than that it is clean. Internal battery is still strong, rated at 3v, providing 3.1v. Nothing in manual about error code. Anyone have ideas? This unit, when working, sells for $300-$500 on e-bay. Our staff wants a newer one. Any ideas?
Push pull amp-Replacing NPN with a non-complementary transistor (output stage) - Page 1
Forum section: electronics / repair

author: Yamin
author_rank: Frequent Contributor
timestamp: August 20, 2020, 07:50:37 pm
content: I am working on an Onkyo hifi amplifier which has got a shorted channel. One of the final stage NPN transistor is shorted. I have ordered the spares but was wondering if it would be ok to replace it with a non-complementary transistor to its PNP buddy? The shorted NPN is C5198 and the PNP is A1941 (those are complementary pair). I am thinking of replacing it with a 2SC4468 its just for the time being till the spares arrive - I know I could just leave that channel but do need it.Thanks in advance.

author: Yamin
author_rank: Frequent Contributor
timestamp: August 20, 2020, 08:15:52 pm
content: I also want to add the PNP A1941 seems to check out ok measured in circuit. I have ordered replacement as well, would it be a good idea to keep the current 1941 in for the time being of course?

author: Mr Evil
author_rank: Regular Contributor
timestamp: August 21, 2020, 11:35:59 am
content: From the datasheets, they look similar enough that I would expect it to work with a 2SC4468 instead. The 2SC4468 has lower ft (20 vs 30MHz), so be careful to check that the amp is still stable.

author: David Hess
author_rank: Super Contributor
timestamp: August 22, 2020, 04:28:14 pm
content: Yes, it is very feasible to use a replacement which is not the complementary part as long as the performance is roughly the same. Distortion *might* be higher but not significantly so.
Push switch cap, transparent lightpipe - Page 1
Forum section: electronics / repair

author: Audiorepair
author_rank: Frequent Contributor
timestamp: August 19, 2022, 12:53:58 pm
content: Hi,I'm looking for these push switch actuators.They are transparent to show the LEDs on the PCB through the actuator when the switch is active.These are on a Behringer DI box, but I also have a Samson headphone amp with the same things, only with an oval actuator instead of the rectangular ones shown.So I hope they are at least a little bit generic.Cheers.
Putting an old ALPS variable resistor push/pull switch - Page 1
Forum section: electronics / repair

author: gkmaia
author_rank: Frequent Contributor
timestamp: July 21, 2022, 03:03:53 am
content: I had to put these apart to replace a broken shaft.Now I am really stuck trying to put them back together. I know the position the black and white bits should go, but the spring is a mistery... how does it fit?

author: shakalnokturn
author_rank: Super Contributor
timestamp: July 24, 2022, 09:39:38 pm
content: I've never taken any of those appart and lack detail to guess from your photo.Most certainly it is there to give some "snap" action, mechanical hysteresis.I'd expect either tail to fit a small hole, the spring loops must have room to flip over a little less than 180° when moving from on to off position.
Puzzled by PLL voltages in a Kenwood R5000 Receiver - Page 1
Forum section: electronics / repair

author: jjbunn
author_rank: Contributor
timestamp: September 16, 2023, 11:11:08 pm
content: The attached schematic image shows part of a PLL in a Kenwood R5000 receiver.I'm puzzled by the voltages shown around Q7, a 2SC2668 transistor, and hoping someone can explain them.The Collector has a voltage of 2.8V, which is derived via R53 (1.2kOhm) from the supply of 8.6V. The Base has a marked voltage of 7.2V.This does not make sense to me, so clearly I don't understand how the circuit functions! Shouldn't the Base voltage be set by the voltage divider R51/R52 (22k,33k), so about 22/55*2.7 i.e. ~1V?How can the Base voltage be higher than the Collector voltage in this circuit?Thanks!

author: Kim Christensen
author_rank: Super Contributor
timestamp: September 16, 2023, 11:59:22 pm
content: I would guess that they've swapped the base and collector voltage labels by accident.C = 7.2VB = 2.8VE = 2.2V

author: jjbunn
author_rank: Contributor
timestamp: September 17, 2023, 04:19:29 am
content: Yes! Measurements on the circuit show exactly that ... thanks for the comment!
Puzzled by ribbon connector GRD pins? - Page 1
Forum section: electronics / repair

author: djmarkfromuk
author_rank: Newbie
timestamp: June 25, 2023, 12:34:26 pm
content: As a newbie I'm just wanting to have something confirmed about this connector and the pins 8 and 22, the schematic shows these as connected, surely when I put my probes on both in continuity mode I should hear a sound? Or am I missing something?I've attached the full schematic to this post, but here's a snapshot of the connector part:DDJ1000 Schematic 3 Pages-compressed.pdf(1999.97 kB - downloaded 38 times.)Also, on a schematic when I see a component has GRDLED should I get continuity if I touch probe on that and on to pin 8 or 22 which are labeled GRDLED?Thanks

author: xrunner
author_rank: Super Contributor
timestamp: June 25, 2023, 05:14:15 pm
content: Quote from: djmarkfromuk on June 25, 2023, 12:34:26 pmThey are shown connected so ... there will be almost Zero ohms. A sound? If your DMM is set to continuity mode it will make a sound.QuoteI would think so.

author: djmarkfromuk
author_rank: Newbie
timestamp: June 25, 2023, 11:19:07 pm
content: thanks. All sorted now. There was a broken thru-hole so no connection from top of board to bottom. Did a fix as shown on youtube, and all good now.
PVM Color Loss - Page 1
Forum section: electronics / repair

author: Cj1
author_rank: Contributor
timestamp: June 10, 2024, 08:01:25 pm
content: My PVM only displays in Black & White over Svideo/Composite. However, RGB works fine. I was advised this can be an issue with the color demodulation, which is controlled via the B board on my unit. Im not quite sure what to look for as i dont see any obvious signs of damage or broken solder joints. Is there an IC i should replace or should i just do a full recap of the board and hope for the best?https://archive.org/details/SonyPVM20L514L5ServiceManual

author: Runco990
author_rank: Frequent Contributor
timestamp: June 10, 2024, 08:35:24 pm
content: I'm not going to look through the manual, but I can offer some suggestions based on hundreds of Sony monitors I serviced.You are sure it is set to the right standard? NTSC PAL Secam?Obviously not in "blue only" mode....And finally, before going nuts, I have seen this in PVM's many times, check the color oscillator trim capacitor. I have had this issue MANY times, but mostly in the small 80 series PVM's. A tiny nudge of the color oscillator trimmer would pop it right back in.And... the "L" series does suffer from leaking capacitors..... yep...Hope that helps before you dig in deep.

author: Cj1
author_rank: Contributor
timestamp: June 11, 2024, 05:27:54 am
content: Quote from: Runco990 on June 10, 2024, 08:35:24 pmYes, its on NTSC with an NTSC source. Blue only is off.I know the 8" series had a service bulletin to replace the trimmer pot, however i wasent aware the L series had any trimmer pots as everything appears to be digital. I do see what looks like adjustable resistors on the B board, not sure if thats what you mean?https://imgur.com/a/K7MfJyw

author: Runco990
author_rank: Frequent Contributor
timestamp: June 11, 2024, 06:08:45 pm
content: Not sure... I have not worked on a lot of L models to be that intimate with them. See if you can find where the 3.58mhz crystal comes from and it's on frequency. This setting could indeed be "way off" in the service menu. I haven't worked on these in a long time, so have forgotten a lot.Do check these things before suspecting worse problems. I have seen monitors where someone screwed up the service menu setting to write off the monitor as broken. Quite a few times.Of course you failed to mention if you GOT it that way or you owned it and this just happened by itself.

author: Cj1
author_rank: Contributor
timestamp: July 17, 2024, 11:33:06 pm
content: Quote from: Runco990 on June 11, 2024, 06:08:45 pmI received it this way. I was actually able to borrow a working unit from a friend and swap the boards. The problem goes away when i swap out the B board, however I am not quite sure what component could be causing the malfunction.I suspect it may be a problem with one of the control IC's, however I think those need to be programmed and arent really replaceable.
PWM. Controller for Flyback - Page 1
Forum section: electronics / repair

author: ebclr
author_rank: Super Contributor
timestamp: October 12, 2017, 04:44:37 am
content: I have a sot 23-6 smd ic marked73F492960AThe circuit is like this, Does anybody know what PWM. Controller for Flyback have this mark

author: Armadillo
author_rank: Super Contributor
timestamp: October 12, 2017, 05:34:17 am
content: Its written there. RICHTEK R7735. Not sure the marking.

author: ebclr
author_rank: Super Contributor
timestamp: October 12, 2017, 05:52:58 am
content: The mark73F492960AThe schematic is only for reference, of the kind of circuit, I.m looking for a part who is marked as on the 1st post

author: dave_k
author_rank: Frequent Contributor
timestamp: October 12, 2017, 11:45:45 am
content: can you post a photo of the part?

author: Cubrilo
author_rank: Newbie
timestamp: April 19, 2020, 08:08:52 am
content: I know it's late. Could be OB2273MP.
Pwm driver misterious chip..MCU or standard? - Page 1
Forum section: electronics / repair

author: Emi
author_rank: Contributor
timestamp: December 19, 2019, 07:24:27 am
content: HiI'd like to discover if a scratched pwm driver can be "unveiled" .Board is a classical chinese LY-820 pwm driver but (god damn them) has the chip grinded !!!Could be a tl594 similar..It drives a mosfet and has only few caps and resistors around..Can you help me?

author: Circlotron
author_rank: Super Contributor
timestamp: December 19, 2019, 07:29:58 am
content: Would be handy to show the other side of the board as well so we can see where the tracks connect to.

author: Emi
author_rank: Contributor
timestamp: December 19, 2019, 07:31:18 am
content: Ok..i will post a pic laterGrabbed on web..but NiceCould it really be a tl "something"?494?

author: fzabkar
author_rank: Super Contributor
timestamp: December 20, 2019, 07:15:26 pm
content: The Vcc and Ground pins match a TL494. I would draw a circuit diagram.

author: Emi
author_rank: Contributor
timestamp: December 26, 2019, 10:25:52 am
content: Thanks fzabkar. ..meanwhile i've casually found the solution in a Russian lathes forum. . ( chipmakers.ru)It ' really a tl494 very common chipThe guy here developed some mods to improve originalPerformances..Thanks for your interest
PXI-5922 DFC AT28BV64B EEPROM Data - Page 1
Forum section: electronics / repair

author: express
author_rank: Newbie
timestamp: October 02, 2023, 05:22:15 pm
content: Hello,I have a PXI-5922 that I tried to read the EEPROM off of but installed it upside down in my TNM programmer. Unfortunately, my programmer does not have a orientation or position check for the AT28BV64B device (this seems like a program error as all other devices, including the non-B version of the EEPROM, have this check). Meaning it automatically tried to read device contents, sending VCC to one of the I/O pins.The EEPROM is unfortunately dead and I can't recover data from it.Would anyone be able to provide an EEPROM dump from the PXI-DFC 2.0 board AT28BV64B-20TI EEPROM IC.Thanks
PXI-6250 - Looking for high res photos - Page 1
Forum section: electronics / repair

author: Khaveer
author_rank: Contributor
timestamp: July 03, 2020, 01:48:16 pm
content: Hello everyone!I've recently grabbed a cheap PXI-6250 DAQ card. Unfortunately at the time of the purchase I didn't notice that the card was missing a few passives. Does anyone happen to have this card laying around and would be willing to snap a few high res photos? It would be nice to have full front and back shots of the board, but I'm also especially interested in the area around U59 on the back of the board (I'm looking for the value of R159).
Pye Cambridge FM10D Service Manual ? - Page 1
Forum section: electronics / repair

author: barrds
author_rank: Contributor
timestamp: February 09, 2022, 11:46:04 pm
content: Hi everyoneDoes anybody have a Service Manual for this old transceiver ?Many thanks in advance.

author: CaptDon
author_rank: Super Contributor
timestamp: February 10, 2022, 01:27:59 am
content: Sorry, can't help with the manual. I did however own some PYE battery portable transceivers and the strange thing about them was that they were mostly germanium and silicon PNP transistors and the positive side of the battery pack was chassis grounded. They were on 154.XXX or somewhere in that range and were exactly on the drive-thru frequency of the McDonalds hamburgers right up the street!!!

author: barrds
author_rank: Contributor
timestamp: February 10, 2022, 04:27:07 pm
content: Many thanks for the tip about the positive connected to the chassis.Just in case you need it, I do have the manual for the AM version of the same transceiver the Pye Cambridge AM10D.
PZ-70 Burleigh High Voltage DC Amplifier schematic  - Page 1
Forum section: electronics / repair

author: Pkoff123
author_rank: Contributor
timestamp: October 30, 2024, 12:37:47 am
content: I will trade my first born for the schematic. Cant find it anywhere online. I have to repair like 10 of these. Drawing the schematic from the 1960s layout is torture..

author: tonykara
author_rank: Contributor
timestamp: November 05, 2024, 05:42:06 pm
content: Watching!
Q455 J2M Transistor? - Page 1
Forum section: electronics / repair

author: Wil_Bloodworth
author_rank: Regular Contributor
timestamp: March 17, 2024, 09:11:28 pm
content: Can anyone tell me where to find a Q455 J2M transistor or how to look up a replacement for it?Thank you,- Wil

author: Wil_Bloodworth
author_rank: Regular Contributor
timestamp: March 17, 2024, 09:23:04 pm
content: If this helps, here is the (terrible) schematic of where it goes.

author: fzabkar
author_rank: Super Contributor
timestamp: March 17, 2024, 09:39:06 pm
content: TR1 is a TRIAC. The logo belongs to Teccor.This old databook might provide some clues. For example, "4" appears to be associated with a 400V device.https://ia902506.us.archive.org/0/items/manuallib-id-2595393/2595393.pdfSince F1 is a 1A fuse, I'm guessing that would reflect the current rating of the TRIAC.Possible choices ...https://www.google.com/search?q=2a+400v+triac+to-92

author: Wil_Bloodworth
author_rank: Regular Contributor
timestamp: March 17, 2024, 11:04:57 pm
content: Thank you! That helps tremendously.- Wil

author: floobydust
author_rank: Super Contributor
timestamp: March 18, 2024, 01:03:34 am
content: It's used in a basic phase-control (light dimmer) circuit for the soldering iron temperature adjust.I also think it's a 1A sensitive gate TO-92 Teccor triac. "Q4___" is 400VConsider BT131-600. Z0107 is popular in appliances but not sensitive gate.B&K 181-007-9-001 "Triac 0.8A"If I was in there maybe upsize to a 4A TO-220 part, but they have a different pinout, not MT1-G-MT2.The meter bridge rectifier diodes D2,3,6,9 are B&K 150-008-9-001 "Germanium diode 1N67" and known to fail.The other rectifier diodes D4,5,7,8 are B&K 150-008-9-001 "1A, 600V Silicon diode" like 1N4005.Attached is B&K 1655 schematic I found that is a bit better.

author: Wil_Bloodworth
author_rank: Regular Contributor
timestamp: March 18, 2024, 01:09:42 am
content: Wow! Thank you so much! That’s definitely above and beyond.- Wil

author: fzabkar
author_rank: Super Contributor
timestamp: March 18, 2024, 01:12:58 am
content: Another version of the same thing:https://www.eevblog.com/forum/projects/help-configuring-acs724-to-monitorlimit-current-of-iso-variable-ac-power-supply/?action=dlattach;attach=1191646

author: Wil_Bloodworth
author_rank: Regular Contributor
timestamp: March 18, 2024, 02:38:44 pm
content: Not sure where y'all found the parts list but that is perfect. Thank you again!- Wil
q6ac toolkitrc smart charger no power but clicking sound - Page 1
Forum section: electronics / repair

author: dbuergi
author_rank: Newbie
timestamp: September 26, 2025, 06:35:29 pm
content: Hi all,i got this non working charger as a present and would like to repair it.Turning the charger on i get a clicking sound from the internal power board but nothing else happens. With a thermal cam i can see that the mosfets on the bigger mainboard heat up before clicking stops so somehow there is a protection i think.I separated the boards and tried to power up the mainboard directly but my power supply set to 12V and 2A goes down to 1V and 2A. Only the two mosfets next to the powerlines heat up.I removed them and tested them in diode mode. Both Show 0,5V after activation so they should be fine. I cannot find any shorts and look for help now. Maybe anybody else has problems with the charger?Also looking for replacement mosfets is a pain. Is the AO6407 correct?

author: ercan4434
author_rank: Contributor
timestamp: September 30, 2025, 06:31:10 pm
content: Hi,"but my power supply set to 12V and 2A goes down to 1V and 2A" probably your power supply switches to constant current mode which means there is a short in the circuit. Can you post the full board image?Also the mosfets in the picture are AON6407.
QC35 headphones power switch replacement - Page 1
Forum section: electronics / repair

author: sillygoose
author_rank: Newbie
timestamp: November 16, 2020, 04:18:35 pm
content: I have a pair of Bose QC35 headphones, for which the power switch has broken off. I was thinking of buying a broken pair of headphones to use as a donor to replace the switch, since that is the only thing wrong.I've looked around for this kind of switch (note that the plastic switch bit is chipped off), but can't seem to find one anywhere. Is this a common kind of 3-mode, spring loaded switch or some proprietary bose stuff? I'd like to buy the switch instead of donor headphones.The switch has two fixed positions for on and off, and a spring loaded third position for bluetooth settings.Thanks in advance!

author: pbarton
author_rank: Frequent Contributor
timestamp: November 16, 2020, 09:09:38 pm
content: Looks likehttps://www.aliexpress.com/item/32759056779.htmlAlsohttps://www.ebay.co.uk/itm/113317098300However, these slide switches do not have the sprung loaded momentary position for bluetooth.

author: sillygoose
author_rank: Newbie
timestamp: November 18, 2020, 11:13:43 am
content: Thanks!The switches do seem similar, and I guess a spring loaded switch is not strictly necessary.

author: pbarton
author_rank: Frequent Contributor
timestamp: November 18, 2020, 05:10:42 pm
content: With a bit of luck, it may be possible to transfer the spring from the original switch into the replacement???
QFP repair: 68030 CPU - Page 1
Forum section: electronics / repair

author: PeteJ
author_rank: Newbie
timestamp: July 10, 2021, 07:20:04 pm
content: Hi all,I've acquired an Amiga 1200 accelerator card, specifically a M-Tec T1230 LC Rev 1.0 and am looking to repair it.From the looks of things, the cause of the failure was due to some of the pins on the 68030 CPU bent and touched neighbouring pins, most likely causing a short.I've straightened the pins and tested the card with no success.Closer inspection with the microscope showed that one of the pins is actually broken (maybe melted) away. The pin itself is a ground pin, and whilst there are numerous ground pins on the 68030 I doubtthey are internally physically connected.What would be the best course of action to repair the broken pin/leg? How likely is it that the CPU in indeed fried?Attached are photos of the PCB, along with the pinout of the 68030.Regards,Pete

author: ataradov
author_rank: Super Contributor
timestamp: July 10, 2021, 08:02:56 pm
content: You have enough of a stub left to solder a couple wires. It is not hard at all for someone familiar with this type of soldering.Ground pins may or may not be connected. But you have a stub, so you can measure it. If there is already a short, then something else is wrong.If this is from just an external short, then there is a good chance the device is still ok.