1202 ALARM

I have a couple of 20 LED solar strings in the tiki bar at the back of the house. After a couple of years outside the strings weren't working so well and opening up one of the solar panel units I found the AAA NiCd cell inside was only holding 0.5 volts instead of 1.2 volts when fully charged. Initially I went to a few shops looking for direct replacement strings but couldn't find any. Then in Home Bargains I found 50 mini LED strings with larger solar panels and a lithium-ion battery for only £3. So I bought 2 of these and chopped off the LED strings as I was only interested in the solar panel units. An initial test with just twist-and-tape wiring proved this upgrade would work. The next step was to take the solar panel units apart and solder the wiring for my LED strings in properly. I decided to mount the solar panel units under the composite roof to keep them dry so that hopefully they will last a few years longer than the ori...

Another garden power tool converted to run on Parkside/Lidl 20v lithium-ion batteries. This is a nice brush cutter from Ozito which had seen good service on an allotment, but had a failed 18v battery pack. I took the same approach as with the Bosch conversion and gutted the cells out of the battery pack and attached a Parkside adaptor plate. Interestingly, of the 5 cells (18650) in the Ozito battery pack, 4 are serviceable and only 1 had failed, just the same as the laptop batteries. It is working well and I still have 2 adaptor plates from my last AliExpress order for more shenanigans.

These nice Sony headphones came in another batch of stuff from a kind Freegle user. One of the drivers (speakers) seemed to have burned out and the earmuffs were badly worn. I had a poke in the spares box labelled 'Speakers & Sounders (Small)' and found a pair of Sennheiser drivers that were the same size. The Sony ones were built into the headphone housing, but were easy to dismantle and the Sennheiser units fitted right in. It was just a matter of soldering the cables in and they were not only repaired, but upgraded. I measured the earmuffs to be 70mm and ordered replacements for $3 on AliExpress. The headphones are light and comfortable, but have the great Sennheiser sound quality. Job done.

I haven't used my remaining Raspberry Pi 2 for a while, but dug it out recently. I had to update the operating system which now has options for over-clocking the CPU to 1GHz as long as you can cool it so there is also an option to run a fan.  The miniature 5v fan recovered from a broken laptop super glued onto a miniature heat sink recovered from a Sky+ box. Prototyping the control circuit using a BS170 MOSFET with the gate connected to GPIO pin 14. Using pin 14 puts the 3 connections in a row (+5v/GND/GPIO14) on the RPi GPIO connector making for easy fitting. The circuit constructed on a piece of stripboard with a recovered 3-pin connector from some long dead piece of kit. The completed fan on top of the RPi's Broadcom CPU with a drop of thermal paste between them. So I enabled the fan and over-clocking and ran the Pi for 2 hours running YouTube videos and a spreadsheet. A little faster but the fan never came on! Seems the heat s...

I was given this really nice HP 350 G2 laptop by a very kind lady on Freegle. As is usually the case it was running slow under Windows. I offered to install Linux, but she had bought a new laptop and just wanted this one to be used. This is the first 15w laptop I've worked on and it needs low power RAM (1.25v), which I didn't have in stock, so I purchased a 4Gb module on eBay for under £5 delivered. This took the total memory to a respectable 8Gb. A 512Gb SSD upgrade (under £20, AliExpress) and a clean install of Linux Mint and I have a decent laptop to do me for the next 3 years. Performance is fine for my needs (mostly web browsing, Zoom and some hobby coding). The CPU is an i5-5200 which seems to be the fastest that the motherboard can handle so I won't be changing the CPU this time. HP Pavilion G6 CPU Upgrade As I usually do, I'm going to cycle my i7-3632M HP Pavilion G6 (above) into the workshop, which will leave two older laptops to pass on via...

Another damaged portable DVD player I got from a kind lady on Freegle. She said it had been dropped and wouldn't play discs anymore. The unit powered up okay and as luck would have it, can read DVD and DivX files from a USB flash drive. A bit of testing revealed that the main turntable motor was only getting 0.5 volts instead of 6 volts and the drive transistor was probably blown. My guess is that when the unit was dropped something jammed the spindle and the stall current blew the transistor.  Anyway, my eyesight isn't up to even trying to replace a surface mount transistor so I thought, why not gut the DVD parts out of this thing and just keep it as a digital player.  And below you can see Chun Yu Fat in the classic action film 'Hardboiled'  playing from DVD files copied on to a USB flash drive. A 32Gb flash drive will hold around 45 DivX film files, plenty of choice.

I took a punt on another retro portable television on eBay which was listed as non-working due to a missing volume knob. It was a Sony which I figured would be built to last and getting it including delivery for £20 I couldn't really go wrong.  It turned out the television works perfectly and I found a matching volume knob in the spares bin (probably from some other piece of Sony kit I dismantled), so a result. The case has a little damage and the tuning knob isn't working properly, but from the photo you can see a signal coming in via my old Acorn Amega RF modulator. And here's a Zoom call on it!! 

I've been trying different component values for the composite video input on the repaired National Commando 505 television. I soldered a screened cable into the entry point to the video circuit by taking R141 (47K) in the schematic off-board. Than I tried different input capacitors and the infamous 75R resistor (which seems to kill the signal). This is digital television coming off a Freeview box.  The mag-mount aerial is handy. I need to work out how to patch up the case and whether or not to spray paint it. I could be boring and go matt black or be radical and go bright red.

Just messing about with the big Dell monitor and a Linx Windows 10 tablet Mike kindly gave me. The screen has a problem with a black bar down the centre which is physical and probably terminal, but it has a micro HDMI output so can drive a monitor. I'm going to get the screen out of the tablet at the weekend and get a part number and a good look at what has gone wrong with it, but the tablet could still be useful as a computer even with no screen! UPDATE!! 27/02/22 I passed this monitor on to Steve from Freegle/Freecycle this morning.  Unfortunately I managed to drop the stand which was glass and shattered, but the monitor will most likely be wall-mounted so not a huge problem. If it fails again it needs a STPS60170CT high specification diode costing about £5.