Repaired some lights on my "new" BMW.
Parking lights, poor connections in cheap aftermarket led bulbs installed by previous owner.
I ended up cutting the plugs and solder the wires.
Number plate light. Removed the light and discovered it was not connected.
After connecting it to the car, I found out that the bulb was out.
Replaced the bulb and still didn't get any light. It turned out that the output on the light control module was switched off due to a high number of short circuits (previous owner had repaired the wiring loom for the hatch.),
After resetting the short circuit counter, the bulb came back to life.
Parking lights, poor connections in cheap aftermarket led bulbs installed by previous owner.
I ended up cutting the plugs and solder the wires.
Number plate light. Removed the light and discovered it was not connected.
After connecting it to the car, I found out that the bulb was out.
Replaced the bulb and still didn't get any light. It turned out that the output on the light control module was switched off due to a high number of short circuits (previous owner had repaired the wiring loom for the hatch.),
After resetting the short circuit counter, the bulb came back to life.
It is called musicians fuse in this area and could be done with cigarette alum. foil in the past.
Musician + smoker = musicians fuse can be a deadly equation.
My next-to-last "repair" was on a 1980 JVC cassette deck, which today got sold on Craigs List to a guy.
I demonstrated it to him, and before the second song on the tape played, I got handed money - SOLD!
I'm sure he'll get good use from it, because it deserves a good home.
I demonstrated it to him, and before the second song on the tape played, I got handed money - SOLD!
I'm sure he'll get good use from it, because it deserves a good home.
This morning I repaired my work laptop. It would power on but just sit there with a blank screen. Forcing power off and turning back on it would not even post.
So I pulled the fan covers off (they were clogged with dust) and cleaned. Still wouldn't start up.
So I removed the entire cover, pulled the battery, pulled the memory, pulled the M2 drive, and pulled the CMOS battery.
Put everything back and when I connected the battery it beeped. Came up with an invalid time message. Went to the bios, set the date and time and it started up fine.
It's a lot quieter now too! 🙂
Tony.
So I pulled the fan covers off (they were clogged with dust) and cleaned. Still wouldn't start up.
So I removed the entire cover, pulled the battery, pulled the memory, pulled the M2 drive, and pulled the CMOS battery.
Put everything back and when I connected the battery it beeped. Came up with an invalid time message. Went to the bios, set the date and time and it started up fine.
It's a lot quieter now too! 🙂
Tony.
A Yamamoto A-08. The right channel would oscillate as the input reached a threshold level. It is otherwise stable with no input signal. A good example of a quiet tube amp that used AC filament supply.
Separate issue was the machined tube sockets, they don’t have enough bite compared to the cheapest conventional tube sockets from China. The Yamamoto PTFE tube sockets all needed a pinch on both sides to make the connection solid temporarily.
Second was a Zero Zone M7 phono preamp kit, a Marantz 7C clone. Stupid thing oscillates in the 300-500kHz region. The board belongs to the thrash heap. Oscillation can be mitigated but it readily picks up 60Hz line noise on the right channel where the AC line passes. PCB layout was mostly spent with single point grounding that they didn’t take into account possible oscillation and line noise pickup. I bet the board design was never tested for stability and performance. The R-core transformer’s low noise potential was completely wasted on this POS kit.
Separate issue was the machined tube sockets, they don’t have enough bite compared to the cheapest conventional tube sockets from China. The Yamamoto PTFE tube sockets all needed a pinch on both sides to make the connection solid temporarily.
Second was a Zero Zone M7 phono preamp kit, a Marantz 7C clone. Stupid thing oscillates in the 300-500kHz region. The board belongs to the thrash heap. Oscillation can be mitigated but it readily picks up 60Hz line noise on the right channel where the AC line passes. PCB layout was mostly spent with single point grounding that they didn’t take into account possible oscillation and line noise pickup. I bet the board design was never tested for stability and performance. The R-core transformer’s low noise potential was completely wasted on this POS kit.
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I have an old computer in the house that was beginning to emit a high-pitch whine when it was on. It would fade in and out over time, but was a rather piercing sound. I figured it was a fan bearing that was dying. Turned out to be a CPU heatsink that was clogged with dust. The fan on the clogged sink was causing it to resonate. Blowing the dust of out the sink made it all nice and quiet again 🙂
yes! 🙂 I was pulling it appart whilst participating in a global meeting using webex on my phone (because I couldn't join on my Laptop).
Was very glad I decided to have a go, as otherwise I would have been off to the city to get the compute team to look at it, and I would have lost 1/2 day at least!
Tony.
Was very glad I decided to have a go, as otherwise I would have been off to the city to get the compute team to look at it, and I would have lost 1/2 day at least!
Tony.
Hi Tony, I've had the same issue with my laptop computer and being under warranty, I had the mainboard exchanged for a new one, problem disappeared for a year and a half, and then came back. The only solution that made sense was to enter bios right after turn-on and wait there for a couple of minutes, then resume booting and it works every time, otherwise black screen, as if some switch was not working. Also, using vga/hdmi out helps for awhile.
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Bought a set of eero mesh routers for a great price, with 1 of 3 described as intermittent power issue in the ad. A little inspection revealed that the jack and not the plug was the issue. It was an SMD barrel jack, but reflowing 3 out of 4 pads my iron could reach did the trick.
Well that's the dumbest design choice I've heard of in quite awhile, but I guess it was inevitable...
A tape measure.
The auto lock, stuck.
Opening the case, I saw a broken small part.
It had to break, I found the case was not metal but all was plastic with a good looking metallization.
Well a rip off. 😡
Did some fix, but not so good.
The auto lock, stuck.
Opening the case, I saw a broken small part.
It had to break, I found the case was not metal but all was plastic with a good looking metallization.
Well a rip off. 😡
Did some fix, but not so good.
Currently working on an old Magnavox AMP-196-AA chassis to use with my computer in the den. Single common cathode resistor of 56 Ohms (measured 52) was producing bias current of nearly 70mA per tube!
I will split it and use 180 Ohm resistors to drop the current to get the dissipation down around 9W per tube.
I will split it and use 180 Ohm resistors to drop the current to get the dissipation down around 9W per tube.
Well that's the dumbest design choice I've heard of in quite awhile, but I guess it was inevitable...
It did strike me as odd. When I saw that I couldn't reach all 4 solder pads, I pulled the board hoping the underside would be more promising...no part of the jack protruded through the board at all to my surprise.
Of course I have 1st gen, which is the only hardware version with barrel jacks. Everything after is USB C.
Still the best $50 I have spent in a while, network screams compared to my old D- Link.
Finally got around to taking a look at my sister's subwoofer, a Velodyne SPL-1000. It was turning itself on & off with each bass note. I checked online for a schematic a couple of weeks ago and found nothing close, so it's been sitting awhile. Last night I poked around inside for a bit, but with no road map I felt like I was spinning my wheels.
Just before heading off to bed last night I checked online again, and found a schematic for the control circuit almost immediately! Dunno what went wrong the first time; I must have misspelled something.
Looking at the diagram, I could see immediately that the trouble must be a leaky 1N4148 diode in the timing circuit - it was the only part that could be producing the measurements I observed. Sure enough, pulled it tonight and it measured about 59 ohms, both ways. So much easier with the schematic! Sis will have bass for Christmas!
Just before heading off to bed last night I checked online again, and found a schematic for the control circuit almost immediately! Dunno what went wrong the first time; I must have misspelled something.
Looking at the diagram, I could see immediately that the trouble must be a leaky 1N4148 diode in the timing circuit - it was the only part that could be producing the measurements I observed. Sure enough, pulled it tonight and it measured about 59 ohms, both ways. So much easier with the schematic! Sis will have bass for Christmas!
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I've just been through a nice old Hitachi HA-330 Stereo Amplifier.
There was an issue with the startup delay circuit that ended up being an out of tolerance electrolytic capacitor. I ended up replacing almost all of the electrolytic capacitors (apart from the main Power Supply filter caps) with new 105 DegC Rubycon capacitors.
The meter lamp needed replacing and I reduced the bias a tad in order to reduce the incredible amount of heat generated while sitting idle. I know this would have increased distortion, but I felt it was more important to keep the output transistors alive.
There was an issue with the startup delay circuit that ended up being an out of tolerance electrolytic capacitor. I ended up replacing almost all of the electrolytic capacitors (apart from the main Power Supply filter caps) with new 105 DegC Rubycon capacitors.
The meter lamp needed replacing and I reduced the bias a tad in order to reduce the incredible amount of heat generated while sitting idle. I know this would have increased distortion, but I felt it was more important to keep the output transistors alive.
After having refreshed an old QUAD 405 amp with a Dada Electronics repair kit, I enjoyed listening to it. But after a while, I decided to do some modification to improve it, with the goal to put it at the level of a 306 or 606.
I did split the PSU, by separating the secondary bobins so I have a set for each channel. I replaced the former bridge rectifier by two sets of ultra-fast shottky rectifier diodes, and doubled the smoothing capacity of the PSU. As a floating PSU, I did split the signal ground from the chassis ground, both connected through 10Ω an 4.7nF, as in the 306 and 606.
A few more mods, mostly described by Bernd Ludwig and Keith Snook, will come after. Step by step.
As I have two more 405s, I'm thinking of changing them to mono amps.
Even my main stereo set has two Devialet Premier in master/slave (mono/mono) mode, I like the QUAD sound very much. The 66 preamp with the 606 amp is a wonderful sounding combi, which I enjoy since 30 years.
I did split the PSU, by separating the secondary bobins so I have a set for each channel. I replaced the former bridge rectifier by two sets of ultra-fast shottky rectifier diodes, and doubled the smoothing capacity of the PSU. As a floating PSU, I did split the signal ground from the chassis ground, both connected through 10Ω an 4.7nF, as in the 306 and 606.
A few more mods, mostly described by Bernd Ludwig and Keith Snook, will come after. Step by step.
As I have two more 405s, I'm thinking of changing them to mono amps.
Even my main stereo set has two Devialet Premier in master/slave (mono/mono) mode, I like the QUAD sound very much. The 66 preamp with the 606 amp is a wonderful sounding combi, which I enjoy since 30 years.
My Chronograph that I designed in 1992. I had to attach a new battery box for a pair of 18650 cells.
It is running an 8052 BASIC processor with 64K external RAM and ROM. 74HC logic with one Lattice PLD.
If it ever really dies, I guess I will have to design a new one.
It is running an 8052 BASIC processor with 64K external RAM and ROM. 74HC logic with one Lattice PLD.
If it ever really dies, I guess I will have to design a new one.
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I just repaired my Geiger counter! Touched up a couple of questionable solder joints and adjusted the HV and bingo!, it started working again.
7 years ago I built it from this kit... DIYGeiger - Geiger Kit - GK-B5
A video of me testing it when I first built it: DIY Geiger Counter - Lens Test - YouTube
Glad to have it working again. Maybe now I will finally put it into a small, handheld chassis/case.
7 years ago I built it from this kit... DIYGeiger - Geiger Kit - GK-B5
A video of me testing it when I first built it: DIY Geiger Counter - Lens Test - YouTube
Glad to have it working again. Maybe now I will finally put it into a small, handheld chassis/case.
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Oh wow, I never knew they used thorium in old camera lenses until I did a google search on radioactive camera lens, after watching your video!
Tony.
Tony.