DIY - Repair Tools for modern electronics

Started by Elantric, September 15, 2015, 04:52:10 PM

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Frankster

A very big +1 vote for the little Rigol DS1054Z scope, I don't know how I ever managed without mine. Apart from the four channels it does serial decoding as mentioned, great for those projects using I2C, SPI or even MIDI. I've been building a lot of Eurorack analogue synth modules in the last year and the Rigol has punched well above its weight in value for money.




admin



admin

#31
Quote from: PaisleyWookie, post: 27317465, member: 162799I'm confused as to how two Zuma outputs (500Ma each) can power a 3000Ma device. I've got a Zuma now for my board, and would buy another if this'll work.

I figure the HX Stomp draws 1200mA (1.2 Amp) "nominal" steady state DC current

But during intial power on  - the power supply needs a bit of Headroom for momentary "inrush current"
https://www.sunpower-uk.com/glossary/what-is-inrush-current/



https://www.loxone.com/enen/kb/inrush-current/



https://www.kew-ltd.co.jp/en/support/mame/detail.php?id=59







How to Measure DC Current

Clamp on to a conductor just the same way as with AC current measurement using an AC current clamp meter. In the case of DC clamp meters the reading is positive (+) when the current is flowing from the upside to the underside of the clamp meter.


https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/


https://www.amazon.com/gp/product/B06XSMDMYV/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/




vtgearhead

I cannot quite see what the resistor is doing - is that in series between supply + and the connector barrel?  And, I doubt that little cap "doubles" the filtering of the supply.

admin

#36
Cap states 106K = 10 Microfarad

but it appears the Resistor is a 5 color type : "Brown, Brown, Black, Red, Red" (11K ohm 2% or 22 ohm (?)  in parallel with the 10uF cap and is a bleed off cap  -

(hard to read the resistor code )

I would expect a decoupling circuit  =  (22 ohm resistor in series with the +DC supply with a 10uF cap to ground) 


admin

#38
https://www.vguitarforums.com/smf/index.php?topic=19475.msg181633#msg181633
QuoteDenzil D'Cruz
3 hours ago
Ryan, the best way to replace a multi-pin chip like this is to cut the legs off the chip from the component side of the PCB ensuring you leave enough of the pin in the circuit board that you can grasp it with a pair of tweezers whilst heating the solder pad from beneath. You should be able to easily remove each leg remanent this way then use you solder sucker to clean up the hole, you might need some solder wick which is resin impregnated copper braid which will give you nice, clean PCB holes ready to accept the new chip.
Also, do not be tempted to remount the heatsink with only one screw - Boss have fitted two for good reasons, also get some heatsink compound to smear between the chip / heatsink interface to aid heat transfer.   Good luck!
Some comments  -
without prior experience with Lead FREE Solder, This is NOT a repair normal folks pursue - without prior experience ( spend a few hours learning to desolder / solder with high temp lead free solder on an old discarded PCB Board  before attempting this type "dead power amp " Katana repair)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1281311/
1) Consumer electronics built since 2006 employ Lead Free Solder which requires special high temp soldering tools and skills  -  _ when replacing a dead  TDA7293 Power amp IC - it works best to use side cutters and cut ALL the pins directly under the IC chip housing  - then remove each pin separately from the PCB board  - one at a time  using a lot of flux and special dilute  lead free solder ( to get things  flowing ) and use a higher temperature soldering iron with an appropriate tinned soldering tip.
https://forum.allaboutcircuits.com/threads/desoldering-lead-free-solder.109784/
https://pdfs.semanticscholar.org/268a/b371b20b9bf08edddd1392172f3dbedd60fd.pdf

At his point I would join VGuitarforums  - and I will try to connect you to Boss US Service



DIY Repair Tools area
https://www.vguitarforums.com/smf/index.php?board=21.0









admin

#42


https://www.circuitspecialists.com/blog/dso150-oscilloscope-the-little-scope-that-can

$39
Specifications:

Vertical
Number of Channel: 1
Analog Bandwidth: 0 – 200KHz
Sensitivity: 5mV/Div – 20V/Div
Sensitivity error: < 5%
Resolution: 12-bit
Input Impedance: 1M ohm
Maximum Input voltage: 50Vpk2pk
Coupling: DC, AC, GND
Horizontal
Max Real-time Sampling Rate: 1Msps
Timebase: 10us/Div – 500s/Div
Record Length: 1024
Trigger
Trigger Modes: Auto, Normal, Single
Trigger Types: Rising/falling edge
Trigger Position: 1/2 of buffer size fixed
Display
2.4-inch color TFT LCD with 320 x 240 resolution
Power Supply
9V DC (8 – 10V acceptable)
Supply Current: 120mA @ 9V
Physical
Dimension: 115mm X 75mm X 22mm
Weight: 100 gram (not including cables and power supply)


https://makeradvisor.com/jyetech-dso150-digital-oscilloscope-review/




billbax

Very impressed with this technique admin - creating a fine 0.6mm hole through tungsten is an outrageous achievement. Great post!

admin

Quote from: billbax on August 07, 2019, 01:45:07 PM
Very impressed with this technique admin - creating a fine 0.6mm hole through tungsten is an outrageous achievement. Great post!

Same technique works for creating pass thru holes in metal bridges for piezo saddle wires