Forum Vaillant boiler F67 fault code problem is board

I see new PS-900 for <$150 on ebay, so value wise that would be the best. FX-971 we don't have good performance testing, other than a few anecdotes. Its most likely a lot better than an FX888, but its not clear how it compares to a top JBC or metcal. ...

Back last year I started to work on that, but meanwhile someone already did a complete reverse engineering and converter: https://github.com/Rav263/fnirsi-wave-decoder

What is the specific HK address? I don't see one on their site. JLC I see one posted online for No.2 On Yiu Street, Shatin, NT, HK

XDM1251 teardown part2 images

XDM1251 teardown images (part1), if anyone curious.

Quote from: Hydron on September 07, 2026, 09:36:50 pm .... I did try and reload default calibration values, and still got the same 0 values for resistances, but K values did change, so clearly it is holding some cal data still! ...

Hi, did you find the solution?

When i read these reports of using AI for software development i am asking myself how those involved think they own their results. Is this a problem? How is it solved? Running models locally may be an attempt to solve that problem. I mean the day befor...

Hi MariuszD As shown in the image below, this is a step-up circuit board built using the MC34063; it takes a 4.2V lithium battery input and provides a 9.0V output. In the output section, an SS8550 transistor is also used for shutdown control; why, then...

Did some more digging... seems a bit more complicated. I identified the Vishay VSH precision resistors on the board, and their TCR is most likely not what is shown in the calibration tables. As someone here already flagged, −272 ppm for the 95.357 kΩ ...

Quote from: bcrist on Today at 04:51:46 pm Quote from: tube_time on February 22, 2026, 01:18:29 am I think a bunch of folks involved in this thread would be interested in this. I've completely r...

Quote from: studiot on Today at 09:19:11 pm I am totally mystified by this thread. I am seeing quotes of replies that I can't see. Schrödinger's quotes?