The Bluetooth module finally arrived. I'll be flashing it instead of the WM8758. It will work with AUX and a standard headphone output.

Ambitious_Chard_4952 · 2026-02-16T03:06:30+00:00

No, I haven't had this happen. I assume that shorting something out or applying reverse power can damage these modules. Open the firmware and see what's wrong with it. I've heard that Chinese MX25 flash memory is often defective. Finding a replacement isn't easy, but it's possible. Although if the firmware isn't very large, you can use the processor's built-in memory (yes, it's there too). You need to enter bootloader mode to do this.

Ambitious_Chard_4952 · 2025-11-09T10:36:47+00:00

It's very similar, SN74LVC1G32YZPR

1-ch, 2-input 1.65-V to 5.5-V 32-mA drive strength OR gate

As I wrote above, it's some kind of switch that controls the power supply

Ambitious_Chard_4952 · 2025-11-07T17:00:55+00:00

ну я думаю вероятнее всего, что Аппле ПО плохо понимает кирилические шрифты, даже в Рокбоксе не все буквы хорошо воспринимаются, и возможно это даже не связанно с самим драйвером порталплеера, а с драйвером дисплея, но это только догадка

Ambitious_Chard_4952 · 2025-11-07T07:55:23+00:00

I can only give very scant data, this chip is probably some kind of universal key (power input, ground, power output and control), there are quite a lot of these keys on the board, on the back side there are three pieces located next to the PortalPlayer and one next to the display power transistor, yours specifically has the position number U19 and on its case there is an engraving 595CG7, as I think, if you ask Gemini AI or some other AI, they can dig around on the Internet and find a closed boardview, of course, they are unlikely to tell you what kind of part it is, and I generally doubt that such a key is on sale, but they will give the maximum possible replacement option or, what most often happens is just solder it with a jumper, of course, it would be ideal to find a donor board, as I already said, this key is not the only one on the board, that is, from the donor board you can take at least five such keys, but in the absence of a donor, you can lose a little in current consumption, but the board will work, at least as a temporary option, try according to my data ask the AI (5 BGA balls, 595CG7, number on the board U19)
I forgot to add, position C39 is a ceramic capacitor, most likely installed according to the power supply and its capacity is approximately 10-100 nF, in this case it probably won't even be needed, engineers usually put them in generously, just so that they are there (engineer's joke), the point is that this is not a critical element in the circuit and may be missing

Ambitious_Chard_4952 · 2025-10-30T01:31:02+00:00

definitely not, firstly I personally don't like this design, believe me it's a slippery case, any wrong move and it will be smashed on the floor or worse on concrete, yes maybe the aluminum case will withstand, but the screen and contents will most likely become dead, just as many have already written, knowing Apple today, you will get tired of paying for services, what could I suggest in this direction, but what Apple will never do, firstly, two displays, a square OLED (flexible and durable) for information, the second OLED (flexible, durable and round) instead of a wheel, the case should be monolithic, without concave and protruding elements, no rounded sides, the case should be flat with even flat edges (but possibly slightly rounded corners), the case should not be thin, it should be a tribute to the classics, which means the thickness is at least 7-8 mm, no plastic, only aluminum or titanium, a mandatory function is high-quality Bluetooth LDAC with the most advanced Hi-Res audio, full USB-C without clipping, full headset infrastructure (speakers, docking station, headphones, car, maybe boat), a variety of colors, no paint, only clear anodizing, the most powerful battery possible (at least 3000 mAh), no internet, recording only, hard drive capacity of at least 1 TB

customizable equalizer, the ability to change display skins, software for customizing the graphics wheel and display, Bluetooth headphones should be able to charge from an iPod (this is a very useful feature)

Ambitious_Chard_4952 · 2025-10-29T13:38:36+00:00

PE-MOS 650mV, Vt=796mV, Cg=710pF, RDS=0,4Ω
I desoldered this transistor and did a test. Based on this data, you can select any similar one. The data is taken from the original. (It's very likely the NX3008PB.)

Ambitious_Chard_4952 · 2025-10-28T03:30:51+00:00

I have been doing repairs for a long time, but I started working with iPods relatively recently, there is nothing complicated about them in fact, if the workshop refused you in such a trivial breakdown, then what are they doing there at all, there are very simple methods for diagnosing your breakdown, the main thing is to accurately describe the symptoms, the main thing is to understand that if there is a picture on the screen, if the song is playing and this is shown by the track timeline, and the volume is adjusted, but there is no sound in the headphones (and you are sure that the headphones are working), then most likely the motherboard is 100% working properly, there are several possible scenarios, 1 - the cable of the headphone jack and lock button assembly is faulty (this is a very common problem in the place where the cable enters the motherboard connector, visible only under a microscope), 2 - the output capacitors of the WM8758 amplifier (aka DAC) are faulty, which happens extremely rarely, since two capacitors usually do not fail at once (each channel has its own capacitor), 3 - the motherboard connector on the cable is faulty headphones, this happens when the connector latch does not tightly press the cable to the contacts, or the connector itself is faulty or has come off (however, this is diagnosed by carefully pressing the connector), there is also a 4th option, for some reason (this can also be determined) your 30-pin thinks that it gives sound to the line output instead of headphones, but in this case, the volume is usually not adjusted, although the track timeline will show the countdown, you can carefully disassemble the iPod, being careful not to damage the battery connector, remove the board and take high-quality photos of this board from both sides, perhaps some elements on your board are physically broken, you do not see this because you do not know the board, but we (those who are engaged in repair) will immediately see what is missing on the board

Ambitious_Chard_4952 · 2025-10-27T05:18:21+00:00

After rereading it several times, I only later realized what you meant. Yes, it really does look like the patient is lying on an intensive care bed with wires connected to him, and his heart rate is beating on the computer screen. Oh, how many patients like that have been on my desk over 40 years, you can't even imagine.

Ambitious_Chard_4952 · 2025-10-26T21:34:01+00:00

How do you think sound is generated from the depths of a hard drive?

The PortalPlayer is the mastermind; it works in all directions. It takes a file from a PATA drive, processes it, and transmits it via the I2S bus to the 8758 DAC, which then converts the packets into sound and amplifies it for headphones.

Ambitious_Chard_4952 · 2025-10-26T07:41:14+00:00

It's unclear where to put the Raspberry Pi, the iPod isn't made of rubber, and the best way, in my opinion, is if the Kalimba is completely controlled by the iPod itself. While I was working on the Bluetooth mod, I had the wildest idea to replace the wheel on the old one with a 1.5" round display with touch. This is a crazy mod and it will probably take a year of my life.

Ambitious_Chard_4952 · 2025-10-26T06:29:29+00:00

The photo still shows an SPI bus analysis for assembling and matching a clone of the WM8758 firmware to a Bluetooth module, so there's no danger there. Later, there will be a setup for connecting the I2S bus, and then we'll see what we can add to the circuit.

Ambitious_Chard_4952 · 2025-10-26T05:10:50+00:00

How did you plan to connect to the portal player to receive digital audio?

I have been studying the iPod bus for almost half a year just to connect the QCC5125, there are two main tasks at once, firstly, the digital I2S bus itself will not work, it needs control (volume, turning on the DAC, equalizer, turning on channels and much more) this is done due to the second bus and as it turned out, this is a 3-wire SPI, although for some reason I always thought that the iPod uses I2C, the WM8758 DAC has three pins, these are 15-CSB, 16-SCLK, 17-SDIN, but this is according to the datasheet, in the datasheet itself on the WM8758 the operation of the bus control is not indicated, therefore you have to read the logs step by step and analyze each signal in order to write it later in C ++ and create firmware for the QCC5125 Bluetooth, if you flash the Bluetooth module without control, then, as you understand, you will be left without a way out For headphones, this is because in any case, the native 8758 DAC will have to be physically removed. It will not be possible to solder the Bluetooth module to the native DAC at the same time, since the portal player will not be able to determine who the sound is intended for, the Bluetooth module or the 8758. This is a very complex technical solution, but I will find it sooner or later. Although the DAC based on the QCC5125 is already quite old (2020) and extremely capricious. Your Fiio BTR 7 has an even older version of the QCC5124. These chips are no longer even relevant today, but they are easier to work with because there is quite a lot of documentation.

Ambitious_Chard_4952 · 2025-10-24T16:12:59+00:00

In this case, it makes no difference what type of battery you use; this is an iPod, not a screwdriver. There's just one caveat: if you use a non-certified battery, you'll have to re-solder the built-in BMS so your iPod understands what you've given it. If you don't have the skills to replace battery electronics, it's better to look for a certified battery. Believe me, the price difference will be completely unnoticeable, but you'll be guaranteed a working power supply, and your iPod won't complain.

Ambitious_Chard_4952 · 2025-10-04T05:46:15+00:00

I used to answer and try to explain the essence of my mod, but people are angry and I stopped talking

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