Wednesday, February 21, 2024

Peavey Combo 115 repairs

My brother bought me a Peaver Combo 115 for repair.  They used controls with plastic shafts that broke off. They upgraded the design to use controls with metal shafts but they are out of stock everywhere unless you want to pay a fortune for them.

Here is a picture of the controls with their values and part numbers next to them.  You can see the broken controls in the picture.

This shows what the insides of the amplifier looks like. All of this could be 1/4 the size if it was made today.

The only critical controls that were broken were the 50K linear tone controls. The crossover and compressor can be ignored or bypassed.

Here is a possible source of parts.  The needed parts will cost you over $50 with shipping and may not be in stock.

As a solution I purchased 10 x 50K pots with knobs on eBay.  Short wires have to be run from each control to the circuit board.  I have seen this kind of solution before.


Wednesday, February 7, 2024

WARNING - 5630 LED strip lights are burning out!

I have many 5630 LED strip lights that have burned out after only 2 months of use.  Here is what they look like now that they have been replaced:

I used these LED strips to replace the five foot flouresent light bulbs in a street sign.  Here are the bad LED's as they were starting to burn up.  By the time I replaced them many more had burned out.

Monday, February 5, 2024

Arduino Powered Colloidal Silver Maker with Nokia 5110

I saw that someone had copied my colloidal silver maker design and their design was trending at number one when you search for Arduino Colloidal Silver Maker.  So I thought I would improve my previous design to use a Nokia 5110 LCD in the design instead of the 1602 LCD.  This Nokia display gives five or six lines of display so you can see more information.

I use a computer power AC adapter to power the colloidal silver maker at about 19 VDC. Most people say that 18 to 20 volts is ideal for this application. 

This is a picture of the Nokia display.  I added the ability to see the current setting as it reduces every time the current exceeds 1ma.  What else do you think I should display on the LCD?

Adding the Nokia display is easy as it just plugs into the Arduino Uno except for jumpers to 3.3 volts and ground.  Voltage dropping resistors are not needed as the Nokia chip is 5 volt tolerant.  You can jumper the BL (backlight) to 3.3 volts or add a jumper or resistor right on the LCD.

The top view has not changed from the previous version.  There is a voltage divider so the arduino analog inputs would not be damaged and a L293 motor driver IC module.  The motor driver has its own internal 5 volt regulator.  Use a separate ground for the voltage divider to avoid motor noise.

Here is the code:

#include <Adafruit_GFX.h>

#include <Adafruit_PCD8544.h>

// Software SPI (slower updates, more flexible pin options):

// pin 7 - Serial clock out (SCLK)

// pin 6 - Serial data out (DIN)

// pin 5 - Data/Command select (D/C)

// pin 4 - LCD chip select (CS)

// pin 3 - LCD reset (RST)

Adafruit_PCD8544 display = Adafruit_PCD8544(7, 6, 5, 4, 3);

// Pins for Colloidal silver maker

int CS1=10;

int CS2=11;

// Pins for stirrer

int Stir=9;  // Moved to pin 9!

int Shutdown=0;

// Variables for time

int hours;

int minutes;

int seconds;

long hour = 3600000; // 3600000 milliseconds in an hour

long minute = 60000; // 60000 milliseconds in a minute

long second = 1000; // 1000 milliseconds in a second

float AN1=0.0; // Analog inut 1

float AN2=0.0;

float temp1=0.0;

float temp2=0.0;

float CUR=0.0;  // Current in ma

int CurSet=255; // Current Setting

void setup()   {


  display.setContrast(60);  // Default is 50

  display.clearDisplay();   // clears the screen and buffer

  pinMode (CS1, OUTPUT);

  pinMode (CS2, OUTPUT);

  pinMode (Stir, OUTPUT);


void loop() {



  // Reverse current every 30 minutes

  if (Shutdown==0){

    analogWrite(Stir, 128); // 1/2 supply voltage

    if (minutes<30){

      analogWrite(CS1, 0);

      analogWrite(CS2, CurSet);    }


      analogWrite(CS2, 0);

      analogWrite(CS1, CurSet);    }



    analogWrite(CS1, 0);

    analogWrite(CS2, 0); 

    analogWrite(Stir, 0);     }






  if (CUR > 1.0) {CurSet--;} // Reduce PWM




  display.print(AN1);  // Analog 1



  display.print(AN2);  // Analog 2



  display.print(CUR);  // Current



  display.print(CurSet);  // Current Setting

  // print the number of seconds since reset:

  long timeNow = millis();

  hours = (timeNow) / hour;             

  minutes = ((timeNow) % hour) / minute ;

  seconds = (((timeNow) % hour) % minute) / second;

  display.setCursor(0, 40);








  if (hours>3){ // Time under 4 hours



  if (CUR>2.0){ // Current under 2ma





There was an error in the connections to the L293 motor driver in my earlier version.  The VIN of 19-20 volts goes to pin 8.  Also the stirrer has been moved to D9 as the Nokia LCD needs D3.

Saturday, February 3, 2024

The Capacitor Disaster is back!

 About 20 years ago the market was flooded with faulty capacitors.  This is happening once again.  Three times within one week I had to fix things with bad capacitors.

The first one is a ONN Roku TV model 100012589.  The symptom was that ths screen goes blank but the sound keeps working.  When I removed the cover I could see the bulging leaking capacitors.

The next one is a internet repater.  It worked great for about 6 months then the power light became dim and it emitted a buzzing sound. I used two capacitors to fix this in the hopes that it would last longer this time.

The third one was a 5 volt power supply AC adapter.  I did not take any pictures.  Is anyone else seeing thes bad capacitors all too commonly once again?