Can we fix a dead nebula projecting spaceman?

Summary

The transcript describes troubleshooting an astronaut nebula laser projector that arrived dead on delivery. The user methodically tests each component, determining the power cable was faulty. Upon disassembly, the internal construction and circuits are compared to a previous model, revealing differences in the power supply, control boards, motors, and unusual optical assembly. Although fixed with a new cable, the performance seems inferior to the prior version, but still produces an intricate laser effect when directly illuminating the optical components.

Takeaways

• 😀 The video details repairing a broken astronaut nebula projector.
• 😞 The projector was dead on arrival but the seller refunded and didn't want it returned.
• 🔌 The projector cable was faulty, replacing it fixed the issue.
• 👀 The internal design was very different from a similar previously repaired projector.
• 🔋 It uses a buck regulator power supply circuit to provide efficient 3.6V.
• 👂 Infrared remote control signal is passed directly to the LED board.
• ⚙️ The LED board can drive 4 motors, a laser and RGB LEDs.
• 🔦 The optical assembly is less efficient than the previous projector.
• 🪟 A rotating rippled glass disc and mirror reflect the laser beam.
• 📐 Firing the raw laser through the optics creates a complex morphing effect.

Q & A

What was the issue with the astronaut nebula projector that arrived?

It was completely dead on arrival, even though nothing looked burnt or damaged. It simply would not power on.

What was determined to be the root cause of the issue?

The faulty cable - once it was swapped out with a cable from another unit, the projector began working.

How does the infrared receiver function if it's enclosed inside the backpack?

It's unclear how the infrared signals can reach the receiver inside the enclosure. This was noted as a questionable design choice.

How does the optical assembly in this unit differ from the previous one examined?

Instead of a spinning diffraction disc, there is a rotating mirrored rippled glass disc that the LED shines through. This provides a more complex rippling effect.

Why is the light output of this projector less than the previous one?

The light passes through the rippled disc twice, losing intensity. The previous design had simpler, more direct optics.

What regulated power supply circuitry was found in the lower section?

A buck regulator using an MT2492 chip, along with an inductor, filters the input down to a steady 3.6V supply for the circuits.

What functionality does the microcontroller section provide?

It controls the motor, laser and LEDs via transistors and MOSFETs. There are 4 motor channels and 3 LED channels for red, green and blue.

What simple hack provided an interesting alternate lighting effect?

Shining the laser directly into the optical assembly, rather than the LED. This created a complex rippling projection.

Why might there be 4 motor channels when only 1 motor is used?

It's unclear - perhaps for compatibility with other products or configurations that need more motors.

What are the overall conclusions about this astronaut projector?

While an easy cable fix, the optics don't perform as well as the previous unit. But the circuitry and mechanics are still quite interesting.

Outlines

00:00

😕 Faulty Cable Caused Non-working Astronaut Projector to be Returned

The paragraph describes an astronaut nebula projector purchased for Christmas that arrived dead. Testing found the projector itself works with a cable from another unit, indicating the cable is faulty. The supplier refunded the purchase and the unit seems fully functional except for the bad cable.

05:01

🤔 Exploring the Internal Mechanisms and Circuit Boards

The paragraph opens up the projector and explores the internal mechanisms and circuit boards. Differences from a previously disassembled projector are noted. The power supply, LED driver circuits, motor drivers, laser diode, and unusual rotating rifled glass optical assembly with mirror are analyzed.

10:03

🎯 Infrared Receiver Embedded in Backpack for Button Control

The paragraph examines how the infrared receiver for remote control button presses is curiously embedded inside the astronaut backpack. It is unclear how the infrared signals can reach the receiver in this position. Wiring for the LED head module matches a previously disassembled projector.

15:03

🔦 Comparison Testing Against Previous Model

The paragraph concludes by noting the projector is dimmer than the previous one disassembled. It plans testing to compare brightness side-by-side. Shooting the laser directly into the optical assembly creates nice effects but the product itself is disappointing.

Keywords

💡astronaut

The astronaut refers to the nebula projector product that the person is trying to repair. It is shaped like an astronaut with a laser and lights. The astronaut theme is central to understanding the product and the narrator's repair efforts.

💡repair

A key theme of the video is the narrator attempting to repair the broken astronaut nebula projector. They diagnose the issue, open it up, analyze the circuit boards, and try to get the lights and laser working again.

💡cable

The initial fault is found to be with the cable connecting the astronaut toy to power. Replacing this cable with a working one from another toy solves the power issue.

💡circuit board

The narrator analyzes two circuit boards inside the astronaut. One controls the power supply, the other the lights, motors and laser. Understanding the circuit boards is key to diagnosing the fault.

💡laser

One feature of the astronaut is a laser projected through rippled glass to create nebula patterns. Getting this laser working again is part of the repair effort.

💡LED

LED lights are another feature of the astronaut projector. The narrator identifies the LED circuitry on the boards and tests the LEDs during repair.

💡motor

Motors are used internally to spin the rippled glass plates that diffract the laser and LED lights. The narrator identifies motor control circuitry on the boards.

💡power supply

One circuit board contains a buck regulator power supply to convert the input voltage to 3.6V for the lights and motor. This power supply is analyzed.

💡infrared

An infrared receiver inside the astronaut detects signals from the remote control. Its placement and wiring is analyzed during repair.

💡optics

The narrator analyzes the optical assembly with lenses and mirrored glass that manipulates the laser and LED light. This creates the nebula projection effects.

Highlights

The cable was faulty, resulting in the whole product being condemned

Interesting power supply design with voltage regulator to lower dissipation

Infrared sensor tapped directly across the 3.6V supply rail

Voltage divider circuit allows microcontroller to detect which button is pressed

Four motor drive channels allow control of multiple motors

Mosfets used to directly switch the laser and LEDs

Different resistor values used for each LED color

Ripple glass disc rotates to create interesting optical effects

Double pass through ripple glass reduces brightness compared to other design

Hacking laser directly into optical assembly creates complex morphing projections

Disappointing performance compared to previous astronaut design

More complex optical assembly but lower light output

Regulated supply aims to lower dissipation vs raw supply

Fault was just the cable, easy fix

Interesting to take apart, different and more complex than previous design

Transcripts

it is another nebula projecting laser

astronaut but this time it's different

because it's completely dead and it

comes with a cover

note hello Clive here is an alternative

astronaut nebula projector it was

purchased from

teu uh for Christmas but was dead in

arrival timu said there is no need to

return it and have refunded presumably

they want the e-w to be our problem

indeed I've opened it to look for

anything obvious I could fix but

everything looks in order at least

nothing is burnt so drawing except that

I can see pretty sure I put it back

together correctly the only thing I can

guess at is a motor which is a two- pin

connector shoved into half a four pin

header but I don't think that should

cause catastrophic fear of the entire

astronaut unless it's plge reversed I'm

not 100% which way it was originally

also interesting the position of the

infrared receiver which is inside the

backpack I'm not confident this could

ever work how does the infrared get to

it it is the same 3+2 wires connecting

the head as your for me but the infrared

presses the buttons that will be

interesting right

right so it came with this lead so the

first thing to actually do here is get a

little power analyzer and just see if

it's drawing any current at all if it's

like a short circuit or something so I

shall plug it into this little rang

analyzer it's drawing nothing and then

buttons

nothing okay let's rule out the obvious

first meter

is the polarity correct in this is it

even working this is set to 20 volts

that's

perfect so is the lead okay and is the

polarity

correct R in

here nothing that's an interesting start

hold on I'm going to get the other lead

from the other astronaut just give me a

second here where is it there it is

that would be a very very easy fix but

it never ever works out that easy does

it I shall plug this lid in here

hopefully the tip and ring of the crack

polarity let's plug it

in and push

buttons uh the NAB projector is now

working it's the cable that's faulty

right so now we've done that let's

explore it for is everything working

here oh there's the laser mhm not a very

bright laser I have to say God I can't

even see the laser unless

it's oh it's doing its fading thing

right okay enough let's open it up and

see what the circuitry is like in theide

how it compares to the other one I took

apart right I shall tie a knot in this

one just to remind me this is the dff

one I could just stick it in the bin

right now I may just chop the plug off

at the end if it's that end and just use

it as for the

lead so he says the infrared receivers

in here that's kind of interesting let's

pop this open I'm going to need a thin

screwdriver for

this that is not the suitable

screwdriver this is where I just scatter

all my screwdrivers everywhere I didn't

plan this did I um I'm not seeing my

screwdrivers one moment

please I found a suitable is screwdriver

let's see this infrared sent in here

let's uh zoom in a little

bit I still have a box with uh good

chunk of fanfold computer listing paper

in it from the era that I was doing

quite a lot of software writing in uh ql

super basic and uh Doss uh what was the

one with DOs it was a Microsoft quick

basic I think it

was what do we have what do we have what

do we have what do we have do we have

the infrared sensor in in here it may

just see through the

plastic so unscrew that

one unscrew

that there is the infrared sensor there

is a power

supply that's interesting this is

different from the other

one so it's got three buttons uh I'm

guessing it's

power plus one of the the the buttons

are all common to one reference so this

may be a standardized uh voltage regular

Supply

excellent that's intriguing what are we

going to find in the head is it going to

be the same mechanism as before with the

uh Distortion disc just basically um

spinning inside a little sort of cradle

which was quite an interesting

construction are these screws coming out

I think they're coming out they might

not be coming

out they do feel very loose but they

might not just been snug in too tight

which is good not like those ones you

get from China where they've just

basically just run it right into the

point of this is completely

different what the heck this is very

different there's the LED Source

projecting down onto something that is

then firing out at an angle this is very

interesting can we get this out a little

bit further as this glued in there is a

circuit board we should analyze the

circuit

board there's a laser as is often the

case there is a little four pin

connector with just two jammed on I

wonder why there's two drives are there

two transistors for driving that it

looks like there are two h options or

transistors

here I'm not actually even seeing a

transistor in one of those positions I'm

seeing the three for the

LEDs right there well let's unplug

everything so that one was in the

one to the

side that's actually a five pin

connector this is wedged on that's

exciting uh this is a

little connector for the well this is

the laser on

here these are well jammed and if these

been glued in it feels like

it but they may just be a tight fit here

is the one for the

LEDs and here's the one for the other

bit let's WAP this out and see what's

what's going on

here this is very

odd a first time for seeing this now the

other one the infrared receiver was

actually mounted below this pattern of

holes I wonder how efficient this one is

compared to the other one I may try them

next to each other and just see how

bright it is at this point I don't even

know how it's working is it a reflector

that it's actually rotating a a chromed

plastic

disc and is the laser glued in properly

or is it going to fall out like the

other one

did this ain't comeing out too easy

these uh screws required to come out too

let's just take all the screws out

that's usually a good

result now it's coming

out what a weird little mechan

ISM that is worth

exploring how

strange yeah we'll have to open that up

uh and I shall Also let's see is the

loser it's just wedged in

again with the defraction disc in front

of it the defraction material just of

jammed in there right okay well we know

what we'll do now I shall uh take a

picture of Sucker board and we shall

reverse engineer it and uh then take it

from there one moment

please reverse engineering is complete

let's

explore so the unit is divided into two

sections this it turns out is a power

supply section that's why it's got the

inductor it's got the infrared which

sends data up and it's got three

switches which uses a voltage divider to

provide a voltage level up to the top

let me Zoom down this

uh a bit

more so the incoming Supply comes in the

Jack here and there is a capacitor

across that for General decoupling it

would have been nice to put a diod in

that particularly given this is actually

regulating down 3.6 volts but they

didn't this is the inductor that couples

with this a616 3 Z now it's worth

mentioning that that a616 3 Z is

actually uh Mt 2492 that's a good

correlation of numbers there and this uh

is basically it's a little Buck

regulator that she uses the inductor to

drop the voltage down by providing

pulses and it effectively just kicks

back against it acts like a a resistor

to limit the current but ALS but using

inductive techniques it just makes it

more efficient and then there's a uh

voltage divider here that provides the

signal back to the feedback pin and by

changing the value of these resistors

you can set the output voltage in this

case they've used 3.6 volts and the

reason they've done that is to reduce

the dissipation of the resistors for

things like lasers and LEDs notably the

LEDs the infrared sensor is just tapped

directly across that 3.6v supply and

this pin goes straight up um and the

potential divider is formed by this

resistor down here and then these

resistors are switched in by the uh

switches let me show you the schematics

for this section

first I've abbreviated it

somewhat incoming USB Supply smoothing

capacitor Mt 2492

uh regulator and it produces the 3.6

volts that then goes up to the module

there's an infrared is tapped across

that Supply Rail and then it goes up to

the module and then the other module and

then this is the 100K resistor going to

the positive Rail and then each of these

resistors is switched to the negative

rail when you push the button and it

just means the voltage in the switch

connection that goes up to the other

control module again H just when it sees

if it says 3.6 volts it knows no buttons

are pressed if it says say for instance

you press this middle button it would be

half that it be 1.8 volts that would go

to and by looking at the voltage it

knows which button has been pressed it

means that they could use one line for

as many switches as they wanted and then

there's two other Connections in that uh

connector and it's two Zer volt

connections okay next circuit

board here is the next circuit

board the supply comes on here there is

loads of decoupling that capacitors

dotted about left right and Center all

over the circuit board there is a 4.7

Ohm resistor and a capacitor to provide

a filtered supply for the

microcontroller uh the motors the reason

there are so many connections is because

it can drive four Motors there's a

common positive connection and then

you've got 1 2 3 4 each with its own

transistor and um back EMF diode so

there's uh one uh the one motor that is

used with it 330 ohm resistor cuz it's a

standard npn resistor there's the second

motor there's the third motor and

there's the fourth motor it's just

basically four channels I wonder why

they've done that then for the laser

we've got a 7.5 Ohm resistor in series

from the power supply and we've got a

a2shb mosfet switching that directly

control for the microcontroller and then

for the LEDs we've got another three

a2shb mosfets and a resistor in series

of each color so 4.7 ohm for the red 1

oh for the green and 33 ohm for the blue

interesting there's two positions for

resistors here wonder why they've done

that that maybe it was for the red was

originally designated put there because

the red has a high voltage to drop and

more will be disappeared across the

resistors anything else worth saying no

that's it it's one of those things that

took a lot less time to tell you than it

took reverse engineer although to be

honest it wasn't that hard reverse

engineer here is the controller I'll

Zoom down this a little

bit so there's the uh Supply Comm on 3.6

volts there's the Zer volts there's the

little decoupled Supply 4.7 ohm leading

down to capacitor just to try and filter

noise from the microcontroller of the

switching of things like Motors we've

got uh the npn transistor the j3 Y

switching the motor there times four if

you want cuz there are four positions

the laser has its resistor going to the

positive rail then the laser diode have

just drawn one little beam of light

there cuz it is a laser and then going

down to the mosfet which has a 4K 7 P

down resistor but is driven directly

from the microcontroller for the the

LEDs this circuit is repeated three

times we've got the LED a resistor 4.70

1 ohm and 33 ohm for red green and blue

and then it's down to a mosfet again

with the 4K 7 pool down resistor and

that is it now let's take a look at the

interesting Optical module this module

here and it's not as good as the other

system it produces a different

effect if we take a look at it I'll zoom

out a little bit here so you can see it

in more detail I'll zoom out a bit more

cuz it's very big yeah

we have a this is the case open here so

we've got the cating lens for the LED

circuit board the LED circuit board just

basically has one of those Standard 1

wat 3 wat type beads on it and that uh

goes into the end of this uh cating lens

which is a total internal reflection

lens and that focuses the beam down onto

this rotating disc the disc is rippled

glass with mirror mirroring in the back

and it's just straight onto the geared

motor so that rotates slowly the beam

comes down goes through the Ripple

bounces off the mirror comes back

through the Ripple again and I'll show

you that effect and then gets diverted

uh through this uh front lens and then

far out the front of the unit I don't

think there's any other lensing that is

it this is just a a clear cover in the

front of this however it's not very

bright but see if you actually point the

laser down through here into this that's

a very different matter so I'm going to

set that up and I'm going to show you

the facts and what they look right right

now so one moment please

the unit is now running I shall turn the

light off and show you what this looks

like and this is it I have to say it's

not as bright as the other unit it's a

nice module but it really doesn't quite

put as much light through as the other

one because the other one is basically

just the LED and then it's rippled glass

and then a lens to focus that it's just

straight out the front of the unit this

one is trying to fire it through two

layers of the Ripple Glass effectively

which produces an interesting effect but

isn't as good now let me show you it if

I do a little hack and I put the laser

through this Optical assembly

instead so I'll let you judge is this a

better effect I'm not sure well it's

coming across on camera it's quite a

detailed complex effect but because the

mirror the laser is being shot into that

mirror and then back out again it

creates a fairly complex morphing

Rippling effect that covers quite a

large area it's not too bad an effect

but anyway watch your eyes the light is

coming

back so in summary um quite a

disappointing fault that you know the

cable had basically resulted in the

whole product being condemned as such

because it's faulty H but quite

interesting to take apart very different

to the other one although it looks

identical in the terms of the case the

whole functionality is different the

circuit boards are different it's

strange that it's using the regulated

power supply H to lower the dissipation

that's maybe a better move this actually

seems a more complex Optical assembly

than the other one particularly because

it requires the mirrored uh presumably

glass rotating disc the rippled disc but

it just doesn't pack out as much light

as the other one does because Perhaps it

is just trying to get too much into a

small era but an interesting thing a

very interesting thing and certainly

smacking the laser into the uh into the

optical assembly provided good and

interesting results but there we have it

uh it was an easy fix it just needed a

new cable but um to be honest it's not

as good as the other one it's uh just a

bit disappointing in terms of

performance but other than that

interesting circuitry and an interesting

Optical

assembly