HP E3610A power supply  (Solved) - Page 1
Forum section: electronics / repair

author: Remy
author_rank: Newbie
timestamp: January 08, 2023, 11:04:46 am
content: Hello, happy new years to everybodyAs y am french, so excuse me for my bad englishY try to repair Hp E3610, but i dont find solution. Y have only fluke multimeter, no scopepotientiometer are both in maximun (current an voltage).Pb : when I switch range (8v to 15V) nothing happend. Output stay at about 15V all time.Y check all alimentation test point an it is ok (TP 9, 1, 5, 8 ) .The only change is Tp2 moving up from 16.5V to 26.4V.So, y change U4 (double op amp) but it is the same. Output of this op stay stable. I make mesurement at Tp7 an y have -4.75 / -3.25 for range 8 /15.Is there someone find this on this type of equipement?Thank you for your helpRegardsRémy

author: wn1fju
author_rank: Frequent Contributor
timestamp: January 08, 2023, 01:37:53 pm
content: The HP E361x power supplies have known problems with the electrolytic capacitors. Whether it is a thermal problem (some are near the warm main transformer) or a poor design (insufficient ripple current capability), they tend to leak electrolyte which creates havoc on the main board.I suggest you pull all the electrolytic capacitors and check for wet electrolyte underneath. Scrub the board with alcohol thoroughly before you replace or reinstall any capacitors. I assume you have some way to test the capacitors with your DMM.This may or may not be what is causing your problem, but it is worth doing anyway. On my HP E3611A, I saw leaking electrolyte near a few caps, so I replaced those. A few months later, the unit malfunctioned and it was due to leaks underneath the capacitors that I didn't originally pull.

author: Remy
author_rank: Newbie
timestamp: January 08, 2023, 06:30:44 pm
content: thanks for your answer.I replace all the electrolytic capacitor by new part, and clean printed board before soldering them.but power supply does not go on. Same problem than before.Y dont really know what to do and it is difficult to understand schematic and how does it work.Y read some post on this forum about E36xx, but y dont find same problem and how to resolve it.

author: free_electron
author_rank: Super Contributor
timestamp: January 08, 2023, 06:57:15 pm
content: depending on the age of the machine there are variants. you may need to install the bleed resistorhttps://siliconvalleygarage.blogspot.com/p/e3610a-e3611a-e3612a-e3614a-e3615a.htmlAnd cleaning off capacitor electrolyte needs to be done with vinegar, followed by a 50/50 mix of distilled water and IPA ( isopropylalcohol). There are different kinds of electrolyte. some are water based, some are alkaline ( the older ones). the vinegar bath makes sure the older types are neutralised.

author: Remy
author_rank: Newbie
timestamp: January 11, 2023, 03:27:15 pm
content: Good morning,some news from my E3610 power supply.After applying all recommended changes (thank you to "Free_electron" for the link), range switching still does not work (8v/ 15v).The list of amendments is as follows:_replacement of all electrochemical capacitors_Suppress C5 and C4_Replace C12 with 470uf 50v_installed resistance R 46 (bleed resistor)_installed capacity 220pf paralel on R6Then check the voltages at the different test points and everything seems OK (+12V, +5V _1, +5V_2, -12V, and V Tp2). Note that V Tp2 changes well when you switch the range!As the output voltage still does not switch according to the range, replacement of integrated circuits U1, U4, U5.The range control still doesn’t work!!!Then I also checked Q2 and the transistor works (hfe = 50).Here’s where I am and I don’t know what to do. If you have an opinion on this strange breakdown, I would very much appreciate your help.Thank youRemy

author: free_electron
author_rank: Super Contributor
timestamp: January 11, 2023, 04:36:18 pm
content: Wait a second. I think you misunderstand these suppliesThis is essentially a supply that can give "up to 15 volts at 2 ampere" under all conditions. When you want more current you can get 3 ampere at up to 8 volts.This is NOT a range switch. The output voltage does not magically double. It is a power dissipation limit to protect the power transistors in the supply. It simply makes sure you don't drive them in thermal overload. They did this to be able to use a small heatsink.That range switch is essentially a power dissipation limit switch. This supply is made for 30 watts.

author: wn1fju
author_rank: Frequent Contributor
timestamp: January 11, 2023, 06:51:03 pm
content: Yes, free_electron is exactly correct. I am embarrassed that I didn't also catch the original poster's mistake. I should have known better especially since I have one of these power supplies.

author: Remy
author_rank: Newbie
timestamp: January 12, 2023, 10:31:19 am
content: Good morning,and thank you for your answers.To be sure i understand, the 8v/15/ switch is not a choice of range, but only a choice of available current (or max power).So, if I am on the 8V position, it means that I can have a 12V voltage output if the current is low (example 1A with 12load).If I change load to have a current of 2.5A (3), then yes, I could not have more than 8V on the output but current will be ok.This is how this supply works, right or not ?Thank you for coming back and for taking time to explain me how it works.Rémy

author: free_electron
author_rank: Super Contributor
timestamp: January 13, 2023, 12:13:41 am
content: correct. The supply can give you 15 volt at 2 ampere max. If you stay below 8 volt you can push the button and get up to 3 ampere. Even though the supply can give more voltage on this range , the regulation and output voltage is not guaranteed. It will regulate current BEFORE voltage ( traditional current limiting mechanism. )For light loads you will be able to get higher voltage in the 8v range but the supply will regulate back if you ask for higher voltage.

author: Remy
author_rank: Newbie
timestamp: January 13, 2023, 05:07:03 pm
content: Thank you very much for your answerI now better understand how this power supply works.I’ll be able to use it properlycordiallyRemi

author: jonpaul
author_rank: Super Contributor
timestamp: January 13, 2023, 05:33:16 pm
content: Bonjour cher Remy, bravo pour le intéressant questionLes alimentation marque HP il ya le plus qualitéJ'habite Paris 6emePeut-être nous pouvons appeler ou RDV quelques tempsAmicalementJon

author: Remy
author_rank: Newbie
timestamp: January 14, 2023, 05:22:05 pm
content: Good evening,I reassembled the power supply and performed differents tests with a variable resistive load.Everything is fine and the power is working properly.thanks for your help.RémyPour Jonpaul, regarde le message personnel

author: fmashockie
author_rank: Frequent Contributor
timestamp: October 07, 2023, 06:31:04 pm
content: Just wanted to add this here. I recently repaired a HP E3612A which is practically the same as the E3610A except it has max voltages of 60V and 120V and 0.5A and 0.25A, respectively. The problem with this one had to do with faulty current control. It would only limit current to 60mA regardless of what the setting was. Also, the max current could only be set to ~280mA. I traced both these problems to a dirty CC set button (cleaned with contact cleaner) and a faulty Q5 2N2222. I did a video on my YT channel walking through troubleshooting and repair. Hopefully someone can find this helpful!