Radio tape recorders The King and the Jester series "Potty"** - legendary devices among car enthusiasts, combining nostalgic design with modern functions. However, even these “indestructible” devices eventually encounter problems: memory failures, freezes when turned on, loss of saved radio stations or inability to update the firmware. If your "Potty" begins to "glitch", do not rush to take it to the service - most malfunctions are related to EEPROM memory or software errors that you can fix yourself.

In this article we will look at unique methods for restoring “Pot” memory without a soldering iron, including factory reset, manual firmware update via USB and hardware fault diagnosis. We will pay special attention to typical mistakes that users make during repairs, for example, using incompatible software versions or incorrectly turning off the power during firmware. You will also find links to official and custom firmware, up-to-date for 2026, a model compatibility table and a diagnostic checklist.

1. Signs of memory failure in the “Pot”: when firmware is needed, and when repairs are needed

The first step is to properly diagnose the problem. Symptoms of memory failure are often confused with hardware failures, but their causes are different:

  • 🔄 Cyclic reboot when turned on - a typical sign of damage to the boot sector EEPROM.
  • 📻 Resetting radio stations after turning off the ignition - there is a problem with the non-volatile memory (perhaps the capacitor on the board has run out).
  • 🚫 "NO FILE" error When trying to read USB, the firmware file manager is damaged.
  • ⚡ Spontaneous shutdown after 5–10 seconds - the power supply is faulty, but sometimes caused by errors in the firmware.

If the radio turns on, but “does not remember” the settings, in 80% of cases it is to blame EEPROM memory (24Cxx). This is a chip that stores user data (radio stations, equalizer, time). When it wears out or has power surges, the data is erased. Less often the problem lies in main processor firmware (for example, if the update was previously interrupted).

⚠️ Attention: If the radio does not respond to buttons at all (there is not even a backlight), the problem is most likely in the power supply or fuse. Firmware will not help here - diagnostics with a multimeter is required.
📊 What problem are you facing?
Radio stations are not saved
Cyclic reboot
Doesn't read USB/flash cards
Other

2. Factory reset: soft and hard method

Before getting into the firmware, try resetting the settings. There are two ways in Pots:

  1. Soft reset (via menu):

    Press and hold the button MENU for 3 seconds → select Settings → Reset → Yes. This method clears user data but does not affect the firmware.

  2. Hard reset (hardware):

    Disconnect the radio from the power supply, then press MENU + ON and apply voltage. Hold for 10-15 seconds until the logo appears. This method resets EEPROM completely, including service settings.

If after a hard reset the radio started working, but again began to “forget” the settings after a day or two, the problem is definitely in worn out EEPROM. You can replace it (see section 5) or try to reflash it (section 3).

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After the reset, write down the radio station settings on paper - the next time there is a failure, you can quickly restore them without searching on the air.

3. Firmware update: official and custom versions

The “Pot” firmware consists of two parts: bootloader and main software (firmware). If the radio turns on but is unstable, it is usually enough to update only the main software. If the device is “bricked” (does not respond at all), you will need firmware via ISP programmer (section 6).

Official firmware for models The King and the Jester (including “Pot”, “King”, “Jester”) can be downloaded from the manufacturer’s website:

Radio model Latest official firmware Compatible custom firmware Features
Pot 2DIN KSH-MP501 v3.12 (2023) KSH-Mod v2.8 (added Bluetooth 5.0) Requires USB formatting FAT32
Pot 1DIN KSH-MP301 v2.05 (2022) KSH-Lite v1.3 (simplified interface) Does not support files >4 GB
Android Pot KSH-MP701 v4.01 (2026) LineageOS 18 (unofficial port) Requires bootloader unlocking

Instructions for updating via USB:

  1. Download the firmware and unpack the archive. The file must have a name update.bin (for some models - firmware.img).
  2. Format the flash drive to FAT32 (cluster size - 4096 bytes).
  3. Copy update.bin to the root of the flash drive.
  4. Insert the flash drive into the radio, press MENU and turn on the power. Wait for the “Update OK” message (usually 3-5 minutes).
⚠️ Attention: If during the firmware the radio turns off (for example, due to a dead battery), it will turn into a “brick”. Always update the software with the engine running or the charger connected!

Download the correct firmware version for your model|

Format USB drive to FAT32|

Check battery charge (voltage >12.5 V)|

Have a spare flash drive on hand in case of an error

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4. Diagnosis of hardware problems: what you can fix yourself

If the firmware does not help, check the hardware. Frequent problems:

  • 🔋 Capacitors on the power board - swollen or leaking. Replacing them solves the problem of spontaneous shutdowns.
  • 🔌 Oxidized contacts power connectors and speakers - clean with alcohol and an eraser.
  • 💾 EEPROM chip (24C02/24C04) - if it “burns out”, the radio will not save the settings. Replacement costs ~300 rubles.
  • 🎛️ Volume potentiometers — the graphite layer wears off over time. Solution: spray WD-40 or replace.

For diagnosis you will need: multimeter (ring the power circuits), magnifying glass (inspect the board for microcracks) and soldering iron (if elements need to be replaced). The most vulnerable places in "Pots" are stabilizer 7805 (gets hot during prolonged use) and USB connector (contacts often come off).

How to check a power supply with a multimeter

1. Disconnect the radio from the network.

2. Connect the probes to the power contacts (+12V and GND).

3. Turn on the ignition: the voltage should be 11.5–14.4 V.

4. If the voltage drops below 11 V under load (for example, when turning on a subwoofer), the problem is in the wiring or battery.

5. Replacing EEPROM memory: step-by-step instructions

If resetting and flashing did not help, and the radio continues to “forget” the settings, most likely the microcircuit has failed EEPROM. In "Pots" it is usually used 24C02 or 24C04 (marking is on the body). Replacement takes 15–20 minutes and does not require professional skills.

What you will need:

  • 🔧 Soldering iron (power 25–40 W) with a thin tip.
  • 🧲 Solder and flux (it is better to use Rosin-LTI).
  • 🔍 Tweezers and magnifying glass.
  • 💾 New microcircuit 24C02/24C04 (buy on AliExpress or radio store).

Step by step process:

  1. Remove the front panel of the radio (usually secured with latches).
  2. Unsolder the old one EEPROM, starting from one edge so as not to damage the tracks.
  3. Clean solder pads using braid.
  4. Install the new microcircuit, observing the polarity (the mark on the case must match the mark on the board).
  5. Solder the pins, avoiding overheating (hold the soldering iron for no longer than 2-3 seconds on each pin).
⚠️ Attention: If after replacement EEPROM The radio does not turn on, check that there is no short circuit between the legs of the microcircuit. Also make sure you don't get confused 24C02 with 24C04 - they are not interchangeable!
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Replacing EEPROM solves 90% of problems with loss of settings, but does not help if the main processor is faulty or the firmware has completely crashed.

6. Firmware via ISP programmer: when the USB method does not work

If the radio does not respond to buttons and does not boot (the so-called “brick”), you will need firmware via ISP programmer. This method is suitable for experienced users, as it requires soldering and working with specialized software.

Required equipment:

  • 🖥️ USBasp or CH341A programmer (~500 rubles on AliExpress).
  • 🔌 Male-female wires for connecting to the board.
  • 💻 Program Flash Tool or Khazama AVR Programmer.
  • 📁 Firmware in format .hex or .bin (download on forums, for example, CXEM).

Algorithm of actions:

  1. Find the connector on the radio board ISP (usually 6 contacts: MOSI, MISO, SCK, RESET, VCC, GND).
  2. Connect the programmer to the connector, observing the pinout (the diagram is in the datasheet for the processor).
  3. Run Flash Tool, select the firmware file and click Write.
  4. Wait for it to complete (1-3 minutes). Disconnect the programmer and check the operation of the radio.

If the radio does not turn on after flashing the firmware, check:

  • Correct connection of the programmer (a common mistake is that the MOSI and MISO).
  • Firmware compatibility with your model (for example, firmware from KSH-MP501 not suitable for KSH-MP301).
  • Supply voltage on the board (must be 5 V at pin VCC).

7. Selection of spare parts and where to buy: original vs. analogues

When repairing the Pot, it is important to use high-quality spare parts. Below is a table with proven suppliers and analogues:

Detail Original (item) Analogue Where to buy Price, rub.
EEPROM 24C02 KSH-EEPROM-02 Microchip 24C02-I/P AliExpress, Chip-Dip 80–150
Capacitors 1000 uF 16V KSH-CAP-1000 Jamicon TLN1E102M RadioLotsman, eBay 30–50 (per piece)
Stabilizer 7805 KSH-REG-7805 LM7805CT Any radio store 50–100
USB connector (Type-A) KSH-USB-F USB2.0 Type A Female (any) AliExpress 40–80

Buying Tips:

  • 🛒 For EEPROM and microchips, it is better to choose trusted sellers at AliExpress with a rating above 98%.
  • 🔍 Buy capacitors with low ESR (for example, series Low-ESR from Nichicon or Panasonic).
  • 📦 When ordering from AliExpress, take spare parts - delivery takes 2-4 weeks.

8. Alternatives to repair: when is it more profitable to buy a new radio?

Repairing the “Pot” is justified if:

  • 💰 The cost of spare parts does not exceed 1,500–2,000 rubles.
  • 🔧 Are you confident in your soldering skills or know a proven master.
  • 🎵 Nostalgia or unique features are important to you (for example, built-in RDS tuner in older models).

Otherwise, consider purchasing a new radio. Modern analogues with similar functions:

Model Price, rub. Pros Cons
Pioneer DEH-S4200BT 8 000–9 500 Bluetooth, USB, FLAC support No RDS, weak equalizer
JVC KD-X351BT 7 500–8 800 Enhanced sound, simple interface No video support
Sony DSX-A415BT 9 000–10 500 Great sound, NFC for Bluetooth Expensive spare parts

If you still decide to part with the "Pot", you can sell it at Avito or Yule as a “donor of spare parts” or “retroradio tape recorder”. Price of used devices in working condition: 3,000–5,000 rubles. Non-working copies are bought for 500–1,500 rubles (for repairs or spare parts).

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If the radio is older than 10 years, repairs may cost more than buying a new budget model. Assess the cost-benefit ratio before starting work.

FAQ: Frequently asked questions about repairing the “Pot”

❓ How to find out the model of your King and Jester radio?

The model is indicated on a sticker on the back of the device (for example, KSH-MP501). You can also look at the menu: Settings → Information → Software version.

❓ Is it possible to flash the “Potty” via Bluetooth?

No, officially there is no such possibility. Firmware is installed only via USB or ISP programmer. Some custom firmwares support software updates Wi-Fi, but this is unsafe and can lead to “bricking”.

❓ Why did the sound disappear after the firmware?

Probable reasons:

  • Incompatible firmware version (check your radio model).
  • Reset equalizer settings (go to Settings → Sound and configure again).
  • Damaged speakers or broken wiring (test the circuits with a multimeter).
❓Where can I find a board diagram for soldering?

Schemes of the “Pot” boards are posted on the forums:

  • 🔗 CXEM (section “Autoelectronics”).
  • 🔗 4PDA (repair topic).

Schemes can also be found in VKontakte groups dedicated to The King and the Jester.

❓ How to reset the password on the radio if you forgot?

In most Gorshkov models, the standard password is 1234 or 0000. If it doesn't fit:

  1. Disconnect the radio from the power supply for 1 hour (sometimes the memory resets).
  2. Try a hard reset (see section 2).
  3. If this does not help, firmware via ISP is required (the password is stored in EEPROM).