Update on the Velodyne power supply.

I managed to buy and replace the LNK625PD standby DC/DC regulator, however the situation remained same - still not working, the relay did not switch.

Therefore I tested the secondary part for short circuits - looks OK. Then I put 5V at the capacitors on the secondary part of this standby supply and the relay clicked normally.
So I assumed there must be something I could not see.
Then I checked the LNK625 bypass voltage, that was 6V - OK. Measured the patterns of the secondary transformer on oscilloscope, there were sharp...

Hello all,
my friend has issues with subwoofer Velodyne Wi-Q12 (actual PN Wi-Q12VBE, could be also similar as Wi-Q10 ).
He had it connected and powered at all times, not in standby mode, but in "always on" mode.
The subwoofer is made in 2013, so not 2024 it is 11 years old.
Once during night it started to make noises like helicopter (as he says). Then it may have stopped itself, however after that the subwoofer is completely dead. Absolutely nothing happens, no buttons react. The main fuse was blown, but after replacement still same.

I extracted the...

Hi, I would like to share with you small modification to your Bosch tool 12V and 18V chargers.

You can use it for almost all Bosch chargers what I have seen, for example part numbers GAL 18V-20, GAL 18V-40, GAL 1880, GAL 18V-160, AL 1820, AL1115CV, AL1130CV.

Bosch (today also other brands using the same system like Wurth, Fein) does not care if you destroy your batteries, because they can sell you new ones. So the marketing is telling you only about speed of the charging, so you will not wait for your batteries to charge too long. Me as a customer want the tools and batteries...

IBM R51 schematic...

You can check the flex cable, connector, soldering. Clean with isopropyl alcohol is always good idea. Sometimes I use WD40 to impregnate contacts against corrosion, it cleans them too.
Found the schematic here.
IBM R51 schematic.

[COLOR=Red][[B]Mod. Edit][/B][/COLOR] Do not attach schematics here at Tech section please.
If you want to add a schematic, find an existing thread at [URL="https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/schematic-requests-only"]Schematics...

HI all, I am new to this forum. I hope that would be useful for both sides. I have graduated in radiocommunications and electronics and I am electronic person since my childhood. I worked for company for 11 years as electronics engineer for high end scientific machines, usually some repairs, changes. Now I am working as electronics designer.
My colleague wanted to repair his laptop and showed me this forum, where he found the shematic, so I would like to look around, what is here.
Have a nice day