Posts

Showing posts from March, 2018

In the beginning there was the Word...

Image
In a fit of nostalgia I ordered up 'Making A Transistor Radio' from a second-hand book seller on eBay a couple of weeks ago. This wasn't entirely necessary as the book has been scanned, PDF'd and uploaded several times over the last few years, but I wanted, no, I needed a copy. Why? Because this is where it all began, my obsession with technology and anything that needs electricity to run. As some of you are aware my grandfather Bertie Walsh was one of the first radio amateurs in Ireland and had his original licence under Marconi's patents. His callsign was GI4RY and if you Google that you can still find a couple of references and I think a scan of one of his QSL cards. He made his fortune as a cinema magnate in the 1930s and was fascinated by the technology of the time. So I grew up with this wonder for anything connected to radio or television and my earliest memory (aged 3) was the adults (mainly drunk) going mental in July 1969 when a certain man stepped

Samsung Power Supply

I've been fiddling about with a 40" Samsung LCD television today. I was given this free because the power board had packed in. The previous owner had attempted a repair by replacing the 'Bad Caps' (i.e. blown electrolytic capacitors, Google that one!), but the de-soldering and soldering was a bit ropey looking so I tidied that up and replaced 2 of the capacitors myself as one didn't look right and the other was the wrong value. I managed to find a schematic diagram online for the board (Hansol SIP400B), which was helpful in identifying the capacitor values. Anyway, I put it back in the TV and powered it up and all the voltages coming off the board are correct, but all it does is click. This is the result of a relay on the board switching the circuit from  standby to power on. The red LED on the front panel lights and the set is receiving IR signals from the remote control. This is really frustrating, but as 95% of these boards suffer from Bad Caps, I might just