Trying to FIX: Jacob Jensen Alarm Clock
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- Опубликовано: 8 сен 2024
- Hi, this 'trying to fix' video shows me attempting to repair an alarm clock designed by the Danish designer Jacob Jensen. You cannot set the time and the light doesn't work.
Remember that this is just for entertainment and I am not an expert in these repairs. The processes in the video may not be the best way, the correct way or the safest way to fix these things.
I do love fault finding and trying to fix broken things so I hope that comes across in this 'Trying to FIX' series.
Many thanks, Vince.
this white thing is backlight (electroluminescence backlight - blue light like in old casio g-shock) and it's connected by 2 springs, You can buy it from china or harvest from old cheap mp3 player
BodziuM You’re likely correct. Vince most likely has a few MP3 players laying around given how many videos he’s done.
YEAH Revisit!!!!
Screaming at the screen again, this time "electro luminescent display !" The big yellow transformer is the giveaway, and the oscillator that drives it to produce the big volts needed. Really enjoy these videos though Vince!
BodziuM no it’s not connected through the springs. If you watch and listen carefully. The springs aren’t connect to anything on the main board.
Wow! can't believe how well that plastic screen came up, great stuff....can't wait to see the fix on the electroluminescent display, or maybe replace. The transformer (other yellow thing) will generate a high voltage, so take care when you measure it. "L" is the symbol for inductance and the units are "henry's" (first yellow thing) the caps you were playing with will be there to "trim" the frequency or they have added a bit of load in order to sustain a stable oscillation...good luck!
Is that flat piece behind the LCD an electro luminescent strip, maybe it has died.
Agree. The strip might be ok though. They require high voltage.
Yup, almost certainly an EL tape. That's exactly what the transformer is for - they need high voltage AC. So, the thing to do would be to probe the springs and see if there's an AC voltage when the light button is pressed. If there is, the excitation circuit is fine and the tape is dead. But EL tapes are pretty much indescructible - they work even if you cut them. There would have to be discontinuity across the width for it not to work. So my bet is on some component on the low voltage side of the transformer being bad.
PS: Edited out typos
@@hooeezit yep i think you are spot on, I have replaced many of these on old radio scanners.
But when he measured the springs, nothing come up
@@hooeezit i believe in you :)
L1 is an inductor (just a coil) The backlight which is strip behind the LCD module has indeed failed.
Agree!
WildScotsman 👍
If it's a coil why didn't it beep on continuity.
@@Mobin92 Continuity only triggers on readings below 50. The coil had a reading of 196.6 Ohms. So there's no continuity; the resistance is too high.
a Coil ? but with a few 100 V it should be start lightning ^^ ;-)
That strip of paper connected to the springs is Electroluminecent foil. I work at a Warehouse where we stored those alarm clocks. They have a tendency to burn out. It is a common fault with cheaply produced EL products. EL-Wire, EL-Tape etc.
Wow that's cool information love the channel
Definitely need to look at videos on how an electroluminescent light works and then do a revisit. I had several clocks with that type of light. The whole screen lights up in blue and it hums (guess that's the transformer) when doing so. Compared to a LCD backlight it is much much more effective. Often on weather stations and clocks. I've had several fail and like you I took apart and couldn't find a light! Some are fairly quiet and others much noisier when you press the light with a horrid high pitch squeel in the worst case.
L1 is used to create resonance so the passive piezo buzzer will produce the beep sound.
And the EL strip is used to create the backlight. The transformer is used to create the high voltage for the EL strip. Most probably the switching section for the high voltage supply is not working
I think your right and the light is the rectangle thing behind the LCD display and the problem is with the transformer.
you can always wire a small LED and put it under the lcd (looks like there is enough room) from battery to "light" button so it will not light up for 5 seconds as in manual but as long as you hold the button it will light up the screen :)
22:35 "6th of the 16th"
Fell foul of the US date format there Vince lol
Gave me a good laugh
*Vince says* "hopefully a nice easy fix." I look at length of the video. Nice and long = not an easy fix! GREAT! 😊 THANKS for the great videos. I'm learning a lot! Regards! 😊
45:00 - you have discovered an electroluminescent backlight - that yellow thing is indeed an inductor and that yellow rectangle is a step up transformer. Electroluminescent displays require an AC voltage to activate - the working voltage of that backlight is probably 90v AC. One of the downsides of early electroluminescent lights is the noise from the high frequency circuits used to power the light...
yes the yellow thing with the carbon conductors its flat and lights up when you pump AC into it...
The big yellow L1 component is an inductor, just a coil of wire wrapped round a core, possibly a hollow, air core, possibly a ferrite core. "L" means inductor like "R" and "C" mean resistor and capacitor and "Q" often means transistor.
The value of inductors is given in Henries, usually microhenries because, like Farads, one Henry is pretty big.
A smart enough multimeter can measure inductance. But Vince measured L1 in ohms instead, as a resistor. Which it will also show up as, since a long enough length of wire, wrapped round into a coil or not, has resistance, especially the thin wire needed to fit so many turns. At DC it effectively is just a resistor, it's with AC that the difference happens.
Nice, you are right, Jacob Jensen is the genious behind B&O 70s and 80s design
L1 is an inductor (coil) as others have said! When ever you see the L designation, its coil / inductor. Lucky it didnt blow with the voltage you were putting through it lol! I was praying you wouldn't go beyond 0.3v lol The caps doubled up there was deliberate - they were in parallel to give a larger (specific) capacitance value. They appear to be on one side of the Crystal. It's not uncommon to find PCBs with components never fitted. It can be either for cost savings, a correction to the design, or because the board supports a few variations on feature etc. The light will be mounted under the LCD screen (the white thing). The fact it doesn't read makes me wonder if has failed. Did you try powering it with a low voltage (eg. 0.5v)? Those "dome" switches are super common in cheap devices - the Atari 2600 controller used them! You can "re-dome" them if they aren't working very well, or you can get replacements from time to time on eBay or AliExpress. Great video =D
The flat white thing is an electroluminescent backlight panel, it needs about 120 volts at a few hundred Hz AC. It's a capacitive device and the phosphor between the two electrodes gives off a light when the capacitor charges or discharges. That's what the little transformer is for. There should be one or two transistors to drive the transformer, and a DC-blocking capacitor between the transformer output and the EL panel.
@@skonkfactory Ah, that's what the transformer is for on the PCB! I was wondering about that! In that case, maybe the high voltage is not being provided to it? Check the cap(s) maybe then, and the transistors.
There is another surface mount cap on the other leg of the crystal. The two through hole caps in parallel are used to match the value of the surface mount cap.
@@davebrooks993 It's more likely they are different sizes. It's common to have a different size of cap on one side of the crystal there (in many cases its done with a trim cap).
@@skonkfactory Right. I already knew that transformers could either step down or step *up* the voltage, but I didn't know those backlight panels required such a high voltage, high frequency AC source!
So if the backlight panel needs 120V high-frequency AC, then no wonder it needs a transformer, transistors and a DC blocking capacitor!
In that case, the transformer is obviously for the stepping up of the voltage, the transistors are (probably?) wired in an astable mode to provide the AC-current (one connected to the positive, the other to the negative (if there are two)), and the DC blocking capacitor will filter out any residual DC voltage!
I agree with commenters that the strip behind lcd is a backlight. They use high voltage supplied by the yellow transformer near the piezo buzzer. Couldn't tell u how high the voltage would be, only that you really want to take care not to wreck your multimeter if you go to measure voltage out of that transformer. You could check resistance between contacts of that transformer to make sure the windings haven't failed.
phosphorus light tape...
If I was to guess I would have thought the mini transformer was the more fragile of the components involved so well worth testing... continuity on each side separately then with power on. Might get a couple of hundred volts (nil current) if you are lucky. Mind where you poke your probes.
It uses electroluminescence paint to make the light work, and to get it to work it is VERY high voltage, about 600 volts, hence the transformer and strange looking IC (one of those has probably failed, or the transistor). Also, you can solder the outside edge (tiny dob of solder on each side) of the dome switches if you do not want to use tape.
Hi Vince:
I might be wrong (often am) but I think that Jacob Jensen did indeed do design work for B & O. However, he also did stuff on his own i.e. the thing that you are fixing (not watched whole video yet) and phones etc. I have never bought one, nor even picked one up but yeah I think they have Danish minimalist style that seems to emulate B & O, but yeah not of the same quality.
capacitors in parallel will be to tweak the oscillator frequency fot timing i think the electroluminescent display needs high voltage high frequency signal to make it glow
53:10 - yes that is a great advert for polywatch - fantastic transformation! You will need an AC voltage to test the electroluminescent display (EL). You may be able to make it light with as little as 30v AC. Also I can see it has a 1999 date stamp. It's still a bit of mess inside though, I would expect to see that in a product from the 80s, not from the 90s!
Note that there would be a slightly higher voltage present than a normal battery powered circuit (I doubt more than 100v, probably around 30mA...). It should not have any impact on a healthy person though - just be careful when probing as you could zap the clock IC...
Designed by Jacob Jensen and made in China ;-) The yellow thing is a coil wrapped in heat shrink tubing and the transformer (PWM low to high! voltage) is required for the electroluminescent paint to light up behind the display. Take a look at this video (search for it) on RUclips to understand what it is exactly: "Applied Science Electroluminescent paint and multi-channel control circuit". I have a LCD travel clock and has implemented the same method to light up the display, it is blue/green, not very bright and the transformer makes a high pitch noise when light is turning on.
Maybe it is a good idea to make a list of components to be able to identify it and to know in basic what these actually doing. Big Clive made an excellent video for beginners: "A simple guide to electronic components". But there are also other very nice channels, such as afrotechmod that can give some basic inside information. This can help you to understand better and avoid frustrations and disappointments (because you don't know what is actually going on ).
Nice clock!
As wildScotsman says below L1 is a coil and Bodzium says exactly where the light is. Coils generally have a L designation, Transistors are generally designated Q, T or TR(TR can also be a transformer but usually they are designated by TX). Diodes tend to be designated D, Capacitors are designated C and resistors are designated R.
Just to further what Bodzium says the backlight is open circuit hence you're getting no reading.
The light is in the LCD itself and seems to have gone out. The L1 component is just a wire wound ferrite core inductor.
Am I too anxious for already wanting the revisit? :)
Hey Vince! This video randomly popped up so thought I'd have a watch. You've progressed quite a bit since this one! I'm a bit late to the party but I'd say the light is some kind of HV fluorescent type thing which T1 will generate the required voltage, and why you wouldn't get a reading with the meter on ohms. I couldn't see what drives T1, but it should be one of the transistors such as Q3 possibly. I'd check those and perhaps the capacitors around it. Best wishes Mick.
Those "dead end" tracks, are actually going to VIAs - they connect a track from one side of the board to another, or in some cases to another layer inside the board. Some boards can be multi layer, having 4,6 or even 8 layers. So some via's can take tracks inside the board. It's something you'll get used to as you learn more about electronics.
The yellow L1 - L is used to denote inductors, which are coils of wires, sometimes on a ferrite core, like the one you had there. Common things you will see is
Lx - Inductor
Cx - Capacitor
CPx Capacitor package
Rx - Resistor
VRx Variable resistor (potentiometer) or trimmer
RPx Resistor package
Dx - Diode
Zx or ZDx - Zener Diode
Qx Transistor or FET
Ux or ICx - An Integrated Circuit Package.
Fx Fuse
Tx Transformer
CNx or Jx - Connector
TPx test point
where x is the number of the component in the design.
Some manufacturers have their own systems, I've seen boards with PRx PCx PDx etc, but the system is similar.
The disappointment in your voice, “That’s a bit crude.”
We Learning Together, as you see marked next to component Lx (in this case L1) meant this component is a inductor! Inductor , Plus transformer, means this clock uses electro luminescent ligh not led, EL lights working normally from 12 to 80 volts a.c.(try to measure conical cois, and never aplly any eletric tension in any part of circuit before isolate them from the rest, if not shure, DONT´N DO) the conical coils you saw on the lcd side of board give contacts to back of LCD in black (graphite contacts) it runs the backlight, I assume if is not working , is for 2 factors, first lack of contact from left coil, (the coil was bent remember?) or the oscilator for generate the tension for ELlight is not working or both! try to put coils inside plastic parts to give contacts to black part of back of lcd, so you can try other alternatives(I hope you can understand my very bad english, sorry for that! congrats!
Actually,your English is very good 👍
I think the LCD's Backlight has burnt out, a fix could be a tiny LED soldered to the two tracks that feed power for the time you said the light stays on, only problem is you don't have a schematic, an oscilloscope would come in really handy by having one lead connected to ground and the other to one of the many leads feeding the LCD, And what you would be looking for is a jump in voltage when you hit the light button and that voltage should stay high as long as the light should be on for, once time runs out the jump in voltage should drop down again.
L = Coil/Inductor. The transformer is for the EL backlight. It runs at around 100V AC at around 50-100Hz.
Hi VINCE,
I got mine in the late 90s ,you mis the stand . It is a nice heavy metal stand.
You could buy 3 or 4 modules and stack them on each other ,i got the alarm clock and the barometer module and a temperature Station .
Just Google for jacob jensen modules..
Edit
,if you want it i wil send it to you for free ,i know where the watch and stand is but dont know if i can find the temp module is.
But if i can find it i send them bouth.
edit2
I found it and put a battery in it ,and guess what??? No backlight ,same as yours .
Maybe that was the reason i didn't used it no more my nightstand clock .
But i can confirm there is a light in it ,if i remember it was a very very faint green light .
Still if you want it i will ship it .atleast you get a stand for it .
Vince this yellow thing is a coil for sure. Maybe clean this zebra connection with IPA? Also that transformer could boost voltage for backlight?
Yellow L1 is an inductor to provide the probably greater than 3V needed to make the piezo buzzer work. As others have said, looks like an EL backlight. These use high frequency AC (up to a few kHz), 50V upwards and it's very likely your multimeter even set to AC won't measure anything. Multimeters a're usually tuned for the 50-60Hz range. If you have a oscilloscope (think you mentioned having a handheld one) check the low voltage side of the yellow transformer (T1), that's not the side connected to the springs. Hard to follow with all them vias through the board, but if one guessed that low voltage side will probably be switched by transistor Q1 driven from an output from the blob on the other side of the board.
I learnt a lot from this thanks and thanks for all your other great video work. You strike a good presenting balance and are easy to follow.
8:00 - those are standard fare for 1980s tech - I have several joysticks with those style switches. Two things the go wrong - the metal looses it's spring and the tape looses is tack. Both issues easily resolved!
I have recycled many alarm clocks at the charity shop I volunteer at, too scratched up to be sold and many feature silly things going on with them. I think I may have recycled a model very similar to that and thought about rescuing it because the shape was unusual and interesting but didn’t because it didn’t light up!
"Screaming at the screen!"....lol Love your videos!
It's normal for there to be no conductive path across EL backlight panels. They're basically capacitors that glow if you put high voltage, high frequency AC across them.
Hi there
i have the same Clock, it has a Blue light on pressing the light button, it gloss for 5 Seconds then turned off automatically,
in my point of view the paper that is printed 'Made in USA' and being connected with springs is light and it got faulty, so now remove that paper from back and try to connect a very small LED with springs and it will work,
It will not as smooth and uniform as the original one but i think it will work
I love these fixes for simpler things, as it's more like real life. Someone in my family spilled water on their alarm clock and it didn't work at all. So, I opened it up and cleaned up the buttons
That build quality…
Entertaning as always sad it did not work, maby a revisit later if some things pops up
Wow. Standard Atari 2600 joystick switches. Haven't seen them for years. They are a notorious pain in the ass. They cost nothing and they stop working for no reason. Am surprised that are still been used into something :/ Pro Tip: Clean and bend to fix :P
The EL display is powered by AC that's created by that little oscillator circuit driving T1. It's possible that EL display has failed in some way but not as likely as something else in the circuit. If there is no AC coming out of the transformer then the oscillator may not be running. If you are interested in how they work, the following link is to a well known you-tuber in the DIY/Engineering/Electronics scene: ruclips.net/video/Z2o_Sp2-aBo/видео.html
Maybe the plastic thing works if you turn it to the other side? Also I think that black capacitor is blown up. I love your videos!! Keep the work
"Should be straight forward"... 53min video - oh yeah!!
I sense a revisit in the next weeks :)
Take the "domes" off and and rub contact side on a strip of card soaked in contact cleaner then rub pcb contacts with same card strip. Re-attach domes with fresh capton tape. (Have fixed numerous door entry phones with this method)
It took me ages to memorize the circuit board markings but it's worth taking the time to do it..That's definitely an inductor...Not sure why they use L but I guess there must be a good reason.
same reason we use " U " for chips and " Q " for tranny's, its an old convention that everyone uses, probably something more interesting to it than that if you were to dig.
In honour of the physicist Heinrich Lenz (he of Lenz's law fame), apparently.
Electronics engineers are strange people.
@@mahlapropyzm9180 Indeed.
Btw ive seen many oldet electronica that have multiple disk capacitors soldered in a strand like that im not sure if its cheaper back then or it causes a diffrent flow perhaps like a small and largwr pulse I have no idea but ive definitly seen it multiple times in older tech
Sounds like someone is cleaning the dishes in the background.
Live stream would be awesome!!
Vince on the back paper behind the LCD screen there is a bit of the green track on the out side doesn’t go right to the end like the other side so it’s not making the connection right threw
Those switches use the same type of contacts that were used in old Texas Instruments calculators (those with red LED displays, like the original TI-30), and they were notoriously error-prone. The same type was also used in some 80s joysticks, where they were frequently sello-taped to the circuit board.
EDIT: those disc-shaped components ARE indeed capacitors, specifically ceramic ones, and they are NOT polarised. The "empty" one looks like it was designed for an electrolytic capacitor.
Keep up the good work fella! Always interesting to see what can and can’t be fixed.
That is a tiny clock ☺️
Me screaming the entire clip "l1 is an inductor, don't solder the capacitors there :)" nice method and perseverence, how ever :)
Whack the battery in at midnight, job done ;)
Greetings from Denmark. Always wondered what these things looked like inside. I suspected expensive danish design combined with cheap chinese engineering. I wasn't much off.
Perhaps learn the typical PCB component naming conventions and get a book about basic electronics to help you to identify common components?
Love your vids on the Nintendo Switch! Still haven’t got one myself but hoping to find one soon.
The light just causes the segments activated to backlight, not an actual light per se and likely EL which is what the springs does conveying it to the electroluminescence bit of the screen. If push comes to shove you could prob wire in an alternative EL source that would feed its light down the side of the screen. Think of Casio EL backlighting where it makes the segments glow in the dark, heck you could prob harvest a light from an old watch or even just wire in a section of EL wire.
l1 is just a coil , T1 is used for the backlight to create high voltage AC test the transistors to the transformer and the resistors , c8 tracks don't look good , It works nearly the same way as a ccfl
L stands for Emil Lenz; it means the yellow thing is definitely an inductor. I suppose the light in the display is integrated or the foil works similar to a LED. Do you think you can try it with a little voltage? Maybe better not to avoid to damage it. If the housing is already closed it is not recommended to open it again.
The switch arrangement is quite common with the sellotape it keeps the contacts in place otherwise they will move about 😏
I think that this design is only for looks :) not for electronics :) greetings from Poland :)
Sorry am completely ignorant to the electronics but has anyone solved the light problem? what is the solution? Great video by the way!
Awsome welcome back
i think maybe they reuse the same board for more than one thing because at home we have a thermometer with the same case just with another print on the button which also is a made by Jacob Jensen
Fifury 161 comment of the transformer on the last test listen to the video the clock put out a hi frequency sound like the transformer powered up an it lasted for about 5 seconds. At 45min 40 seconds you press the light button and you will hear the sound
hi vince the high voltage AC is missing look round the transformer for bad joints EL strips go dim with age but dont normaly die
A few decades ago when I was a young man Jensen made premium electronics
Well I got amued when I first took appar my Casio Clock with EL backligh ... I mean .. "just a piece of cardboard ??????". Yep, just that. The EL backlight uses more voltage and you can hear a high pitch tone when you turn it on. I though that this type was gone long ago, in favor of led backligh. But nothing is as uniform and perfect as EL backlight
I have a 22 year old alarm clock, one of the led points seems to either be dead, or dying but I think can be fixed though don't want to wreck it, one of the pieces almost never work but randomly every few weeks it may work for a few days, I wonder if its like the old Game Boy fix where I need to rub a warm solder iron over it but any ideas?
That might be an inducter with two legs on one don't know if it is an antenna to pick up the time signal from Droitwich transmitter.
Awesome video Vince.
The light is luminescent operating on AC high voltage, the transistor and transformer act like impulse power supply step up voltage converter for light panel and the bended spring does not contact with it. L1 is choke (an inductor) and with transistor act like mini power amp for piezoelectric speaker (buzzer). Those 2 caps bias the frequency of the crystal resonator (look at the picture on board) and make it ticking with exact 32768Hz but it don't keep time, the CPU doing this job with the help of it.
Thanks technixbul :-)
Oh look, it's my favorite TV show. Move over, Netflix, I'm watching youtube tonight.
are this things wort anything ? i find dumpster diving a set of 4 of those modules the clock module it looks like yours and 2 sensors all work
These are supposed to be attached to a surface using doublesided adhesive tape for instance on a car 's dashboard
Whats wrong with being made in china......some of the worst things i have ever brought were made and bigclive.com swears by it ....quite literaly lol.
Good video as ever vince
That Polywatch stuff is brilliant! Will it work on any plastic to take out scratches or just clear stuff?
You’re making fun of my fellow countrymen, aren’t you?!! 🧐
RREEEE!!!
😆
Very unlikely to be a build error (cap position) as it was checked fully operational before leaving the factory - “Q.C. PASSED” label.
this reminds me of the porsche designed blackberry. Cosmetics were changed but internals were them same. Lipstick on a pig. but blackberry internals were much better than this
L marking on a pcb i think means either a coil inductor bead ferrite bead
I agree, it is almost certainly an inductor of sorts. I think the two springs on the PCB side facing the display are contacts for a light in the display itself.
@@BertGrink I think you are right the springs are supposed to connect to the light.
Ah looks like electroflourescent plastic
i only like the video because it was made on my birthday
Light Snooze means nothing more then not waking up in a rude way
As others of said those springs are sending AC power to the those pads to power an EL Panel. Thats what the Transformer on the board is for. Set your multimeter to AC and read off the transformers output. The Panel could have failed and luckily you can buy cut-able panels, so either buy a new module or buy a panel that is rated the same to be cut to size(can pick a different color too).
Thumbs up Vince bro 👌👌👌👌👌
The Light on mine works, but trust me it's extremely dim...Dimmer than those dim LCDs. It is a beautiful design but really cheesy electronics (even for those days) Believe me your not missing much without the light functioning. Mine is just for display, I never use it to check the time (too dim) or set an alarm (too much hassle in the age of Siri).
EL light, the problem is either the light, the chip, the transformer or the springs.
You could set the multimeter to high voltage and measure between the two springs. If the circuit works you should get a voltage between them. Try both AC and DC voltage. Gradually reduce the measurement range and see if you get a reading. But be careful, Voltage can be between 30V and 160V AC! The white plate is an electro luminescent light plate as others already stated. The connections are on the carbon pads on the non-white side.
Oh god i was like vince the track is the path onthe otherside of the via lol wich btw you taught me lol
You are amazing!🤙
22:35 - "Sixth (Day) of the Sixteenth (Month)" LOL I cant blame him for that though, because we use a different date format in the US
Both leads are going to the speaker and you still think it’s a light?! That was really dumb :(
The yellow thing is actually a speaker?
L1 definitely is an inductivity, not a light...I would have tried to exchange the cheap metal pieces with some microswitches.
I just bought one used where Its impossible to change the clock :-)
L1 is a inductor. It is used for a resonance circuit, e.g. a radio receiver or a LCR resonator. See here: en.wikipedia.org/wiki/Inductor
The inductor is used with the capacitor to form a LC resonator which generates an alternating voltage for the buzzer. This is how the buzzer generates a tone. The resonance frequency of the LC resonator equals the tone frequency you hear.
The Buzzer is a quarz Buzzer which reacts to voltage changes. This is how it generates tones.