On Sunday, October 17, 2021 at 5:08:18 PM UTC, Joerg wrote:> On 10/16/21 1:00 PM, Joerg wrote: > > With a lot of Sherlock Holmes sniffing I could find it but the > > schematics for those things are horrid. > > > > https://www.audio-thai.com/index.php?topic=15325.0 > > > > I have the HY3030EX (30V/30A). The problem is that it shows arbitrarily > > high currents that aren't there and they are proportionate to the set > > voltage. Shows 11A at max voltage without any load. Of course, nothing > > becomes hot because those are fake numbers. Once it hits overcurrent it > > locks itself up and the output voltage drops to zero. Has to be > > power-cycled it every time. > > > > The internal connections appear to be ok. > > > > Maybe it ain't worth repairing but maybe one of you had that happen? > > > Gentlemen, found it. It wasn't just one poor solder joint but three. All > in the connection from the big current shunt to the 7107 display board > for the current display, plus one on the voltage display board. Not sure > how but this also caused the power supply to lock up. > > If someone else has that happen: Check the blue and black wires going > through a toroid towards the back of the unit. They measure sort of ok > but give them a tug near the solder joints and the resistance changes. > > I can't remember when I last saw such a poor solder job. Basically > consisting of splats and dull blobs. I'll have to take the whole thing > apart and resolder the wires. Considering that they also jammed in lots > of the screws because many things didn't line up that won't be fun. > -- > Regards, Joerg > > http://www.analogconsultants.com/Glad you found it. (I mentioned that resistor first, since I always check high-power parts first; And, it seemed like the PS output was zero, with any load,) ALWAYS first assume solder joints are a cause and re-solder anything remotely suspicious. In a mass-produced product, the solder-process QC is too easily 'relaxed'; and weak joints can be hard to detect. Actually when troubleshooting, there is a long list of basic steps. Here on sed, I tend to assume these were checked off. Would we benefit from a "s.e.d.-level" repair FAQ? regards, RS
Volteq HY series bench supply, wrong current display
Started by ●October 16, 2021
Reply by ●October 17, 20212021-10-17
Reply by ●October 17, 20212021-10-17
On Sun, 17 Oct 2021 12:56:52 -0700 (PDT), Rich S <richsulinengineer@gmail.com> wrote:>On Sunday, October 17, 2021 at 5:08:18 PM UTC, Joerg wrote: >> On 10/16/21 1:00 PM, Joerg wrote: >> > With a lot of Sherlock Holmes sniffing I could find it but the >> > schematics for those things are horrid. >> > >> > https://www.audio-thai.com/index.php?topic=15325.0 >> > >> > I have the HY3030EX (30V/30A). The problem is that it shows arbitrarily >> > high currents that aren't there and they are proportionate to the set >> > voltage. Shows 11A at max voltage without any load. Of course, nothing >> > becomes hot because those are fake numbers. Once it hits overcurrent it >> > locks itself up and the output voltage drops to zero. Has to be >> > power-cycled it every time. >> > >> > The internal connections appear to be ok. >> > >> > Maybe it ain't worth repairing but maybe one of you had that happen? >> > >> Gentlemen, found it. It wasn't just one poor solder joint but three. All >> in the connection from the big current shunt to the 7107 display board >> for the current display, plus one on the voltage display board. Not sure >> how but this also caused the power supply to lock up. >> >> If someone else has that happen: Check the blue and black wires going >> through a toroid towards the back of the unit. They measure sort of ok >> but give them a tug near the solder joints and the resistance changes. >> >> I can't remember when I last saw such a poor solder job. Basically >> consisting of splats and dull blobs. I'll have to take the whole thing >> apart and resolder the wires. Considering that they also jammed in lots >> of the screws because many things didn't line up that won't be fun. >> -- >> Regards, Joerg >> >> http://www.analogconsultants.com/ > >Glad you found it. (I mentioned that resistor first, since >I always check high-power parts first; And, it seemed like the >PS output was zero, with any load,) > >ALWAYS first assume solder joints are a >cause and re-solder anything remotely suspicious. >In a mass-produced product, the solder-process QC >is too easily 'relaxed'; and weak joints can be >hard to detect. > >Actually when troubleshooting, there is a long list of basic >steps. Here on sed, I tend to assume these were checked off. > >Would we benefit from a "s.e.d.-level" repair FAQ? > >regards, RSEven the Chinese can have a bad day once in a while.
Reply by ●October 17, 20212021-10-17
søndag den 17. oktober 2021 kl. 19.08.18 UTC+2 skrev Joerg:> On 10/16/21 1:00 PM, Joerg wrote: > > With a lot of Sherlock Holmes sniffing I could find it but the > > schematics for those things are horrid. > > > > https://www.audio-thai.com/index.php?topic=15325.0 > > > > I have the HY3030EX (30V/30A). The problem is that it shows arbitrarily > > high currents that aren't there and they are proportionate to the set > > voltage. Shows 11A at max voltage without any load. Of course, nothing > > becomes hot because those are fake numbers. Once it hits overcurrent it > > locks itself up and the output voltage drops to zero. Has to be > > power-cycled it every time. > > > > The internal connections appear to be ok. > > > > Maybe it ain't worth repairing but maybe one of you had that happen? > > > Gentlemen, found it. It wasn't just one poor solder joint but three. All > in the connection from the big current shunt to the 7107 display board > for the current display, plus one on the voltage display board. Not sure > how but this also caused the power supply to lock up. > > If someone else has that happen: Check the blue and black wires going > through a toroid towards the back of the unit. They measure sort of ok > but give them a tug near the solder joints and the resistance changes. > > I can't remember when I last saw such a poor solder job. Basically > consisting of splats and dull blobs. I'll have to take the whole thing > apart and resolder the wires. Considering that they also jammed in lots > of the screws because many things didn't line up that won't be fun. > --watch the guy soldering at 23:01-23:05 https://youtu.be/HF0E8WeEUVM?t=1381
Reply by ●October 17, 20212021-10-17
lang...@fonz.dk wrote: ===================> > - > watch the guy soldering at 23:01-23:05 > > https://youtu.be/HF0E8WeEUVM?t=1381 >** Bloody heck !!!! That iron tip must be glowing red to go so fast, just look at the smoke coming off, Terrible, crazy idea. ..... Phil
Reply by ●October 17, 20212021-10-17
On Sunday, October 17, 2021 at 8:48:18 PM UTC, palli...@gmail.com wrote:> lang...@fonz.dk wrote: > =================== > > > - > > watch the guy soldering at 23:01-23:05 > > > > https://youtu.be/HF0E8WeEUVM?t=1381 > > > ** Bloody heck !!!! > > That iron tip must be glowing red to go so fast, just look at the smoke coming off, > Terrible, crazy idea. > > > > ..... PhilAha - the detective Lasse, scores again. Thanks! well said, Phil! they are may get joints that Look ok, on the surface, but.. what darkness lurks beneath? Soldering is a chemical and mechanical process. You can speed up the chemical reaction with higher temp, up to a point. (...Until you degrade the flux, the PCB, etc.) But the mechanical? there's that physical thermal time constant of the assembly.... regards, RS
Reply by ●October 17, 20212021-10-17
søndag den 17. oktober 2021 kl. 22.48.18 UTC+2 skrev palli...@gmail.com:> lang...@fonz.dk wrote: > =================== > > > - > > watch the guy soldering at 23:01-23:05 > > > > https://youtu.be/HF0E8WeEUVM?t=1381 > > > ** Bloody heck !!!! > > That iron tip must be glowing red to go so fast, just look at the smoke coming off, > Terrible, crazy idea.if you are paid by how many you can make in a day it is a great idea ..
Reply by ●October 17, 20212021-10-17
lang...@fonz.dk wrote: ===================> > > > > watch the guy soldering at 23:01-23:05 > > > > > > https://youtu.be/HF0E8WeEUVM?t=1381 > > > > > ** Bloody heck !!!! > > > > That iron tip must be glowing red to go so fast, just look at the smoke coming off, > > Terrible, crazy idea. > > if you are paid by how many you can make in a day it is a great idea .. >** Silly, false criterion. That manager guy looks like he would be more at home running a brothel filled with 12 year old girls. Maybe he does that too. ...... Phil
Reply by ●October 18, 20212021-10-18
On 10/17/21 12:56 PM, Rich S wrote:> On Sunday, October 17, 2021 at 5:08:18 PM UTC, Joerg wrote: >> On 10/16/21 1:00 PM, Joerg wrote: >>> With a lot of Sherlock Holmes sniffing I could find it but the >>> schematics for those things are horrid. >>> >>> https://www.audio-thai.com/index.php?topic=15325.0 >>> >>> I have the HY3030EX (30V/30A). The problem is that it shows arbitrarily >>> high currents that aren't there and they are proportionate to the set >>> voltage. Shows 11A at max voltage without any load. Of course, nothing >>> becomes hot because those are fake numbers. Once it hits overcurrent it >>> locks itself up and the output voltage drops to zero. Has to be >>> power-cycled it every time. >>> >>> The internal connections appear to be ok. >>> >>> Maybe it ain't worth repairing but maybe one of you had that happen? >>> >> Gentlemen, found it. It wasn't just one poor solder joint but three. All >> in the connection from the big current shunt to the 7107 display board >> for the current display, plus one on the voltage display board. Not sure >> how but this also caused the power supply to lock up. >> >> If someone else has that happen: Check the blue and black wires going >> through a toroid towards the back of the unit. They measure sort of ok >> but give them a tug near the solder joints and the resistance changes. >> >> I can't remember when I last saw such a poor solder job. Basically >> consisting of splats and dull blobs. I'll have to take the whole thing >> apart and resolder the wires. Considering that they also jammed in lots >> of the screws because many things didn't line up that won't be fun. >> -- >> Regards, Joerg >> >> http://www.analogconsultants.com/ > > Glad you found it. (I mentioned that resistor first, since > I always check high-power parts first; And, it seemed like the > PS output was zero, with any load,) >It wasn't zero, you could set the voltage correctly until it locked up with a fake overcurrent depending on potmeter settings. The solder problems are in the cable path but also in the ground cable path of the voltage display.> ALWAYS first assume solder joints are a > cause and re-solder anything remotely suspicious. > In a mass-produced product, the solder-process QC > is too easily 'relaxed'; and weak joints can be > hard to detect. >You sure could call that soldering style "relaxed" :-)> Actually when troubleshooting, there is a long list of basic > steps. Here on sed, I tend to assume these were checked off. >Well, you can't always see it, only after I used the mirror from my Bernstein set. I was hoping someone had experienced the same thing. Meatime I found yet another bug, a ceramic capacitor is "touchy" and makes the current display go crazy. So that also needs to be replaced.> Would we benefit from a "s.e.d.-level" repair FAQ? > > regards, RS >-- Regards, Joerg http://www.analogconsultants.com/