HPE HSTNS-PL33 1500w PSU Mod / Hack - anyone know where to find a schematic? - Page 1
Forum section: electronics / projects

author: ubrain
author_rank: Contributor
timestamp: January 18, 2021, 12:21:57 am
content: These old server power supplies are a fantastic bargain. Having been engineered to ensure that expensive chips don't get fried and to be efficient enough that data-centres full of them don't heat up to rival the emissions of a small star, they outlive the purpose they were designed for and provide a really solid base for developing into all sorts of power solutions. That is,ifyou can figure out what to tweak in any particular model to your needs, as they're all slightly different from each other.After great success modifying the 1200w HP HSTNS-PL11 onthis thread, I got a bit excited (perhaps over excited?) and thought I'd try something similar with the 1500w version, the HSTNS-PL33 aka 684532-B21 .Perhaps foolishly, I thought I'd be able to find a schematic pretty easily but it has so far eluded me - can anyone help, or point me somewhere useful?

author: ubrain
author_rank: Contributor
timestamp: January 20, 2021, 02:52:17 am
content: Hmmm.... I'm starting to wonder whether I've hit a dead end

author: ubrain
author_rank: Contributor
timestamp: January 29, 2021, 04:11:58 am
content: OK, perhaps unsurprisingly, no joy with schematics.I have found someone though, who managed to tweak the voltage up to 13v.This is his site(he's got a decent list of projects detailed there)I've tried his mod and, using a combination of fixed and variable resistors, managed to pull 13.8v at start up (val=10K95), and 13.9v by tweaking once powered up. Then of course, the OVP kicks in. So next on the wish list is to defeat/tweak OVP.Any advice suggestions gratefully received.Opening the box was similar to the PL11: just a few ordinary and obvious screws. However there's a sticky pad holding the lid down once the screws are out. After the lid came off so easily on the PL11, it's a little disconcerting as it makes you think you missed a screw somewhere but it just needs a little 'measured' force to release...The 3 images attached below are from YO4HFU's site, this one is to show what was hidden beneath a screen in his photos - Given the PIC16F886 was key to fixing the PL11, I'm wondering whether that PIC33FJ16GS-502 may be significant to sorting the OVP in this one?

author: eblc1388
author_rank: Frequent Contributor
timestamp: January 29, 2021, 08:05:48 am
content: Quote from: ubrain on January 29, 2021, 04:11:58 amDefinitely not.Warning: That part of the circuit is on the primary side which is LIVE, HOT. Don't get electrocuted.My bet is still on the small PCB marked RS232 board as per YO4HFU's site. He had this board removed. His picture of the board does not show clearly markings of some of the ICs or if there is any ICs on the back of this small PCB. If there is any chance a MCU is on this board, then the OVP could be on it and could be modified similar to the PL11.On the second image, can you provide the missing markings on these chips and check if any of the bottom 10-pin connector pin has zero ohm (i.e. connected directly) to the positive output connector?

author: ubrain
author_rank: Contributor
timestamp: January 29, 2021, 11:13:39 pm
content: Wow, It's surprisingly difficult to get the text to show up clearly in a photo.The bottom left-most pin and the little solder tag above it both seem directly connected to the +ve output.

author: eblc1388
author_rank: Frequent Contributor
timestamp: January 30, 2021, 07:23:17 am
content: The CT3253A is a Dual 1 of 4 De/Multiplexer and the IS741A is an UART with selectable I2C/SPI interface. The 402WP is an I2C 2KB EEPROM. These chips all work together requiring a MCU in control, which probably is located on the back of this board.From your investigation, the output volt sensing and OVP divider circuitry, is likely on the rear side of this board. Access to these components are blocked making any modification difficult.

author: ubrain
author_rank: Contributor
timestamp: February 03, 2021, 05:11:21 am
content: Been fiddling around a bit.I unplugged that little sub board near the back (the 4 pin plug at the top of it) last night and thought I had a success when I managed to wind the voltage up to 14.4v. That was without load on it though. Once I added a load, it wasn't stable above 13.9v although it would run at 14.2v for a little while - a few minutes.Oddly, having plugged the board back in, I can still wind it up to 14.4v unloaded so maybe it made no difference at all after all13.8v is about the limit with any reliability at the moment.

author: ukkuty
author_rank: Newbie
timestamp: November 06, 2023, 07:06:57 pm
content: did you get 13.8 v without kicking OVP ??

author: Trurl
author_rank: Regular Contributor
timestamp: November 15, 2023, 10:59:20 am
content: Quote from: eblc1388 on January 30, 2021, 07:23:17 amOn the far left side of the "Controller_PCB"(refer to OP's attached photo above), there is a MCU (MICROCHIP dsPIC33FJ64GS606).Could this be the MCU you suggested?I ask because there was a suggestion on YouTube by "Tao LI"* that "adding a resistor between the 14th pin* of the MCU(dsPIC33FJ64GS606) and ground can increase the OVP voltage."* According to the datasheet, pin14 is "AN2/ASS1/CN4/RB2".*He uploaded a video demoing a hack of the HSTNS-PL33(below) with OVP manipulated via firmware update, and it does not show a resistor based method, but...for those that asked about the possibility of a non-firmware OVP hack with resistors, he referred viewers to the following video of a HSTNS-PL30/PL42 mod, and in the comments section below the video, he commented(refer to the Q&A quotes below)** the possibility of OVP mod with resistors I mentioned above.** Q&A from Tao LI's uploadQ: "Is there a way to modify the OVP with resistors?"A: "Adding a resistor between the 14th pin of the MCU(dsPIC33FJ64GS606) and ground can increase the OVP voltage."Q: "... what kind of resistor is needed there in order to have 13.8V?"A: "To achieve an output of 13.8 volts, you will need to connect a 1.8 kilohm(R1) resistor in parallel. Additionally, for OVP adjustment, it is recommended to parallel an approximately 6.63 kilohm(R2) resistor."WolframAlpha Solver Output 13.8Vhttps://www.youtube.com/redirect?event=comments&redir_token=QUFFLUhqa3cxWDZLRHY2VXRtbVFTT1lYdDZTbURtS19GQXxBQ3Jtc0tuNkNkOEplR3hsN3FaU2VQSmxhc0Y4T1ZnWHRCcm85cjUwWXA3cDlkNXMxYnAySXNhNTZzVGJEeDJ1anYtc1dFb1hmRmtZZUhwVGNUZVJWeHVRV2E5TmxCcV9oX1ZYTUp6UW1FX1AtcUVHZGkwTmo3dw&q=https%3A%2F%2Fwww.wolframalpha.com%2Finput%3Fi%3DR_11%252F%2528R_11%252B39.2%252B10%252B4420%2529%2AV_1%253D0.58%252CR_11%253D220%2AR_1%252F%2528R_1%252B220%2529%252C1%252F%25281%252B3.92%2529%2A12.32%253DR_12%252F%2528R_12%252B3.92%2529%2AV_1%252CR_12%253DR_2%2A1%252F%25281%252BR_2%2529%252CV_1%253D13.8&stzid=UgyNg8WkXAZCVxVE3j94AaABAg.9qLtRAYbpgG9qLzC6Dvb9TAgain, your assessment and suggestions would be much appreciated...

author: pienari
author_rank: Regular Contributor
timestamp: November 15, 2023, 04:51:19 pm
content: Have you better pic from other pic chip?

author: coromonadalix
author_rank: Super Contributor
timestamp: November 15, 2023, 05:59:44 pm
content: have you check on rcgroups ?? they hack server psu's as battery chargers

author: Trurl
author_rank: Regular Contributor
timestamp: November 16, 2023, 09:36:36 am
content: Quote from: pienari on November 15, 2023, 04:51:19 pmIf you download ubrain's attached photo of the "Controller_PCB"(3rd post above) you can zoom in for a better view of the Microchip MCU (albeit the image is not so clear). Sorry, I do not actually have the unit myself, perhaps the OP or other member can provide a better image in focus/close up of the left side Microchip MCU and its surroundings on the "Control_PCB".I've attached a brightened version of ubrain's uploaded image(in post #3) below for your convenience. You can download the attached version at the bottom of this post to zoom the image as you'd like.Quote from: coromonadalix on November 15, 2023, 05:59:44 pmI'm keeping an eye out on the RC scene's sights, thanks... I have googled this matter which led to this post.It seems hacks of this model are still scarce, even though the solution seems to have already been suggested at least by "Tao LI" (note: I'm asking here on this thread for clarification or confirmation if the OVP control is indeed achieved by this Microchip MCU on the long side board.)I look forward to someone's experience taking on the OVP with resistors! Cheers~

author: coromonadalix
author_rank: Super Contributor
timestamp: November 16, 2023, 11:33:47 am
content: while i understand your tenacity RCgroups is your best optionyou will need to reverse engineer it at some point, normally some or many advanced psu's do communicates between them for load sharing and status sent to the server boardhaving dspic33 and other mcu's without the source code will almost get you nowhere .... you have the white connector near the small dspic33, must be the debug / programming port ??the classic fiddling with feedback resistors trimmings / values etc ... as you know it, has it's llimits, you will break ocp ovp cc cv at some point,even the power factor correction circuit, if equipped (normally they do) etc ...you should take on known hackables ones, sure a deal is a deal ...i had some of theses as chargers, bought a few for mere dollars, i have blown some of them while trying the same thing, some of them absolutely need forced air cooling ... if not they will blow under 10 minutes with a faint load (i know it now loll)now a friend use them as chargers for his electric cycle ...

author: Trurl
author_rank: Regular Contributor
timestamp: November 16, 2023, 04:27:21 pm
content: Very useful info below...!(All credit to Tao LI for the PL33 hacks, and Hopper for the PD43 hack)"Tao LI" had apparently uploaded a link*(below) to a site with clear photos of the OVP access point (pin14 of the Microchip dsPIC33FJ64GS606) and the output voltage access points."In the description section of the video (for the HSTNS-PL33 above), there's a linked image* with specific areas highlighted in red font. By paralleling a resistor to the designated points for both ground and over-voltage protection (OVP), you can fine-tune the output voltage and OVP threshold."*https://github.com/darwinbeing/HPServerPSUHack/blob/main/resources/PL33_MOD_HW.pngNOTE:1. The link above not only shows the high res image of the OVP & output voltage access points, but also seems to have the firmware "patch" used in the videos of "Tao LI"(refer to the repository's menu on the left).Also, at the bottom of the left-side menu, there is a "README.md"* which explains the HPHSTNS-PL11/PL30/PL42 circuitry in detail with relevant schematics!(Some relevant examples attached below for convenience)https://github.com/darwinbeing/HPServerPSUHack/blob/main/README.md2. The HSTNS-PL33 and HSTNS-PL30 seem to have the same basic side circuit board, and for questions regarding resistor values for OVP/output voltage "Tao LI" refers inquirers to his earlier PL30 video, in the comments section of which the following is asked and answered:Q:(@ten3mareczkos) "... Hey I want to modify my unit to work with 13.8V ... what kind of resistor is needed there in order to have 13.8V?"A:(TaoLi) "To achieve an output of13.8 volts, you will need to connect a 1.8 kilohm(R1) resistor in parallel. Additionally, for OVP adjustment, it is recommended to parallel an approximately6.63 kilohm(R2) resistor."* Note:"R1" & "R2" as the respective resistors are indicated in the relevant schematics(attached below) from the README.md linked above in which he mentions:"R1 is used to adjust the output voltage of the power supply, while R2 is used to adjust the threshold of the Over Voltage Protection (OVP).The modification mentioned above is not meant to increase the OVP threshold, but rather to trick the dsPIC33FJ64GS606 MCU into thinking that the output voltage has not been adjusted."The link below to the online WolframAlpha Solver contains the equations used to compute the R1 & R2 values by adjusting the desired output voltage "V1"*.*V1 is the very last/far right entry in the orange input cell.If V1 = 13.8V, then R1 = 1.80k, and R2 = 6.63kIf V1 = 14.4V, then R1 = 1.27k, and R2 = 4.7kIf V1 = 15.2V, then R1 = 910Ohm, and R2 = 3.4kIf V1 = 16.0V, then R1 = 715Ohm, and R2 = 2.67k etc."WolframAlpha Solver Output 13.8V(example)https://www.youtube.com/redirect?event=comments&redir_token=QUFFLUhqbTlEOHAyMGExRTNUZ2ZjWmllUzRESWxZVzh5UXxBQ3Jtc0ttUUJlNjkzSER0OGxXckVmSTItM0h5R05QWmZ0dWd1SHJlYkZOTW9MOXREWWUwcHpXdmJ2Y3pkeTByZ3dXWmRCY3NaV2pIQ0JZd1V5UHVreTh3QVUxTDlXaGplTXA1UGhQV3gxYXNTNnF2TVBJb2Rmbw&q=https%3A%2F%2Fwww.wolframalpha.com%2Finput%3Fi%3DR_11%252F%2528R_11%252B39.2%252B10%252B4420%2529%2AV_1%253D0.58%252CR_11%253D220%2AR_1%252F%2528R_1%252B220%2529%252C1%252F%25281%252B3.92%2529%2A12.32%253DR_12%252F%2528R_12%252B3.92%2529%2AV_1%252CR_12%253DR_2%2A1%252F%25281%252BR_2%2529%252CV_1%253D13.8&stzid=UgyNg8WkXAZCVxVE3j94AaABAg.9qLtRAYbpgG9qLzC6Dvb9T"So soldering on one end of each resistor to its respective access point and the other end of the resistor to the nearest/convenient ground soldering point would achieve the result.Tao LI apparently chose to hack with the patched firmware because the OVP access point is a difficult soldering job. But as there is some copper trace going away from pin14, it may be possible to clear some of the green solder mask along this trace at a point where soldering might be easier.The variable potentiometer used in the video is 10K(max) according to Tao LI.So it seems both the firmware and resistor solutions have all been shared in detail all along(in the GitHub repository), just not obviously presented(in the videos). Hopefully someone tries the resistor method and reports back here.Cheers~P.S.TheGen8 PL33(1500W)will require a bit more care in soldering resistors and the currentprices for most of the unitsis for some reasonactually higher thanthe newerGen9 PD43 (1400W)* which is more compact yet easier to solder resistors due to the nature of the access points, and the PD43 seems more available with more attractive prices both on Ebay and Aliexpress (considering international shipping).*HP HSTNS-PD43 1400W Power Enable Method & PinsHP HSTNS-PD43 1400W Pin Assignments Assessed From Breakout Boards For Crypto Mining

author: zorg33
author_rank: Newbie
timestamp: December 06, 2023, 11:30:09 am
content: Hi!I got the 1600W version of this HP Flex PSU (like PD43) and I want to use it's standby output, but all I could find are 3.3V pins.Is it possible that these PSUs have only 3.3V Standby voltage? Anyone knows how many Amps can they deliver?I want to connect some additional circuit to the standby output that controls the turn on/off if the main 12V output.Thanks.

author: yo4hfu
author_rank: Contributor
timestamp: January 13, 2024, 05:36:49 pm
content: More easy way to "disable" OVP for PL33 or similar PSU:- connect a Zener diode 2V7 between MCU pin 14 and GND. MCU input voltage will be always ~2V. In this way output voltage can free changed between 12V...15.5V.Output voltage adjustment:- using a parallel resistor or potentiometer across 220 ohms resistor (R 1K72 = 13.8V, 1K2 = 14.4V)73!