i bought a used device, but they didn't give me a card with a QR-code, and i can't connect to the charger to configure it, i have a pin and a puk

Symptoms:

Amplifier consumes approximately 630 mA quiescent current with no load connected.

All driver transistors in the output stage (for all 4 channels) are running hot.

All output transistors, diodes, ICs, and capacitors have already been checked and/or replaced.

Tests Performed:

1. Verified power supply rails are stable and within specification.

2. Checked biasing resistors and emitter resistors for drift or incorrect values.

3. Inspected PCB for possible leakage paths, solder bridges, or damaged traces.

4. Replaced electrolytic capacitors in both power supply and audio sections.

5. Output stage power transistors tested OK (no shorts or leakage).

Issue:

Despite the above, high idle current and overheating of the driver stage persists.

Request:

Looking for guidance on:

Possible causes of excessive idle current in the driver stage.

Recommended next steps for isolating whether the problem is related to bias circuit, thermal tracking, or feedback loop instability.

Please help me

⟐ Edited March 20, 2026 at 19:38 MST

⟐ Commented March 07, 2026 at 17:15 MST

⟐ Commented July 26, 2025 at 22:28 MST

⟐ Edited by author October 06, 2024 at 6:44 MST

⟐ Commented August 29, 2024 at 19:01 MST

⟐ Edited by author August 21, 2024 at 23:56 MST

The film contact broke on my JuiceBox Pro40. Anyone know where I can find a replacement or the schematic to build my own? Soldering iron ready.

Hi Old turkey,

Do you understand my question & problem

The air compressor is not delivering air.

I dismantled it and that the O Ring on the Piston is worn out

Thanks in advance for any help you can give.

Question Why is the air compressor not delivering air, ?

⟐ Answer edited September 25, 2023 at 11:41 MST

⟐ Commented April 15, 2023 at 10:51 MST

I have a new Top Tech 3 in1 12Ah Booster Jump Pack with Tyre inflator.

It was working and battery nearly full.

I used the light awhile and tried put back to on charge and worked. I was tried change the cable different way but a little light came on when I plug the charge cable on jumper connection and red light didn’t come on and looks like not charge anymore.

I think something fail when I plug in 2nd time.

Battery screen working and show nearly half battery but on charge clock not moving also red charge light not coming flash.

What do you think broken please?

⟐ Edited October 27, 2021 at 12:32 MST

My avh 201ex double din suddenly turned off once going to work like a 3 weeks ago. And this morning in the a.m. it turned on when i moved my car, but in the afternoon i checked again and screen was black again. I had already opened up the console and check for burnt fuses and loose wiring but everything seemed to be intact. I thought the stereo didnt work anymore but since it turned on this morning, im guessing it still does. What can it be??? Any help would be appreciated. Thanks!!

Does anyone know why this happens and how can i fix it?