Repair of MIB3 Preh VW — no sound (3G5 035 820 A/B/C/D) – Passat B9, Golf 8, Tiguan, Arteon,
T-Roc: 1476 zł, 1-3 days, warranty 24 months. Shipping throughout Poland, free diagnosis.
The radio is silent — there is no sound from FM, Bluetooth or navigation, although the touchscreen and reversing camera work perfectly. OEMatic refurbishes damaged components in the audio path and restores sound — without replacing the unit with a new one, without coding.
Not working: sound from any source (FM, DAB, Bluetooth, navigation).
Working normally: screen, touch, reversing camera, Bluetooth (pairing).
A common diagnosis is replacing the power amplifier — a logical lead, because the screen works and at first glance the fault seems to lie further along the audio path. In the MIB3 Preh, however, the fault is before the amplifier, in the signal processing section, i.e. inside the module.
This article concerns only MIB3 OI MQB modules produced by Preh Car Connect (from 2024: JoyNext). If you have MIB3 LG, MIB2 or MIB1, OEMatic repairs those too — send an enquiry for a free quote.
How do you identify the MIB3 OI MQB Preh module?
The MIB3 OI MQB Preh is easiest to identify by the label on the casing — the Preh logo (or JoyNext), the part number starting with 3G5 035 820, and the FAKRA + Quadlock connectors on the back of the module.
Label details
There is a white manufacturer’s label on the top casing of the module. It is worth noting three details:
- Part Number (Part Number on the label): 3G5 035 820 A, 3G5 035 820 B, 3G5 035 820 C or 3G5 035 820 D (in VW systems also as 3G5035820A / B / C / D). Each letter suffix denotes a variant from the same family, which means they are all repaired in the same way.
- Manufacturer: Preh Car Connect. On newer examples you may see the JoyNext logo — it is the same company after the acquisition.
- Platform: MIB3 OI MQB — this information helps distinguish your module from the LG version.
Connectors on the back of the module
On the back of the module you will find:
- FAKRA connectors (standard automotive antenna connectors) — coloured plugs: yellow (GPS), pink (DAB), white (FM). You disconnect them by hand, pressing the latch.
- Quadlock connector (a multi-pin plug connecting the module to the vehicle wiring) — carries power, the CAN bus (the communication network between control units) and the speaker lines.
What this article does NOT cover
There are also MIB3 modules produced by LG — they look similar, but have different electronics. This article concerns only Preh Car Connect / JoyNext units marked MIB3 OI MQB.
Older generations — MIB2 (Harman Becker, Delphi) and MIB1 (Harman Becker, Delphi, Panasonic, Technisat, LG) — are a completely different design. OEMatic repairs all variants — this is part of VW systems repair. If you are not sure which module you have, send a photo of the label — we will quote free of charge.
MIB3 audio fault symptoms
A faulty audio section — the part responsible for sound — in the MIB3 OI MQB Preh gives four characteristic symptoms, from complete silence to constant buzzing. The key point is that the common denominator is no sound from all sources at the same time, while the screen and reversing camera remain fully operational.
1. Complete silence — no source plays
You switch sources: FM, Bluetooth, navigation. You turn the volume up to maximum. Silence. On the screen you can see that the station is playing, Bluetooth is connected, and navigation is giving instructions — but there is still no sound.
The problem appears suddenly. Yesterday everything worked — today it no longer does.
2. Crackling → locked on one tone → constant buzzing
The radio starts by crackling. After a moment it gets stuck on one note and buzzes until the key is removed from the ignition. Only after waiting, i.e. once the capacitors have discharged, does the buzzing stop.
Switching the radio off with the button makes no difference. Turning the volume down does not help either.
3. Lock-up with the radio switched off — a silent fault
The module can lock up even when the radio is switched off. In that case, instead of buzzing there is silence. When the radio is turned on, there is still no sound. It is the same problem, just in a silent version.
4. The computer works normally — only the sound does not
The screen works. Bluetooth connects the phone. The reversing camera shows an image. The settings respond. Navigation displays the route. Only the sound does not work.
That is why mechanics often look for the cause in the speakers or the power amplifier. It is worth noting, however, that if the silence affects all sources, the fault is inside the MIB3 module, before the power amplifier.
If you recognise any of these symptoms, you can send your MIB3 module for free diagnosis — OEMatic will confirm the fault and provide the cost before work begins.
Cause — why MIB3 loses sound
Components in the MIB3 module’s audio path fail electrically. This is a hardware fault, meaning an electronics-side problem. A software update will not help, and a new power amplifier will not solve it either. OEMatic repairs the damaged components on the main board and restores the sound — without a new module and without coding. In practice, this is a standard car radio repair.
Fault in the audio path components
The components in the sound-processing section fail electrically after years of use. That is why the problem appears suddenly. Yesterday the module worked, and today it is silent.
Another risk factor can be jump-starting the engine with a booster pack. Such a voltage spike can accelerate the fault. It is not the only cause, but this scenario occurs regularly.
After a few years of use, it is usually not a software issue. If the problem were software-related, the manufacturer would have fixed it with an update.
How OEMatic confirms the cause
The module is placed on a test bench that simulates the car environment. The test checks the audio inputs separately (FM/DAB tuner, Bluetooth, navigation), the processing in the audio path and the outputs to the speakers. If the inputs and outputs are working, but the processing itself does not, the cause is confirmed: a fault in the module’s audio path.
The “power amplifier” myth — a common but incomplete diagnosis
No sound with the screen working often leads the mechanic to the diagnosis: the power amplifier, i.e. the external amplifier. The logic is simple: if the computer works, the problem must lie further along the audio path.
However, that is an incomplete diagnosis. The fault is inside the MIB3 module, before the signal even reaches the power amplifier. You replace the amplifier for several hundred złoty, fit it, and there is still silence.
The key diagnostic clue is simple: no sound from ALL sources at the same time + a working screen = MIB3 module.
Repair process step by step
7 steps and usually 1-3 working days from confirmation of the job. Diagnosis remains free of charge. Repair only starts after your approval of the 1476 zł incl. VAT quote.
1. Removing the module from the car
You remove the MIB3 from the dashboard. If you are not doing it yourself, a local mechanic will usually remove it in 15-30 minutes.
2. Sending it to OEMatic
Pack the module in bubble wrap and send it by courier. You will find the address and application form here: oematic.pl/en/send-for-repair/.
3. Free diagnosis in the test environment
The module goes to a dedicated test bench: control unit + gateway + display + control panel + OBD2, i.e. the diagnostic socket, + power supply. This is a simulation of the car environment, not a simple “bench test”.
The diagnosis confirms the fault itself and whether the repair is possible. It remains free of charge regardless of the outcome.
4. Quote and your approval
OEMatic gets in touch with a quote: 1476 zł incl. VAT. Repair starts only after your approval. If you decide not to proceed, OEMatic returns the module at no cost.
5. Repair of components in the audio path (1-3 working days)
At this stage, the damaged electronic components in the audio section are replaced, i.e. the part responsible for sound. Original parts are used. The whole process takes 1-3 working days from confirmation of the job.
6. Final test in the environment
We repeat the test on the same bench. Sound must work from all sources: FM, DAB, Bluetooth and navigation. Each audio output is checked separately. The module leaves the workshop only after a positive test result.
7. Return shipment + 24-month warranty
The repaired module is sent back to you by courier. You then fit it back into the car. From the moment of collection, a 24-month warranty applies to the repaired components.
Price, turnaround time and warranty
Repair of MIB3 OI MQB Preh costs: 1476 zł incl. VAT, and the turnaround time is 1-3 working days. The price also includes 24 months' warranty. Diagnosis is free of charge.
| Item | Value |
|---|---|
| Repair price | 1476 zł incl. VAT |
| Turnaround time | 1-3 working days |
| Warranty | 24 months |
| Diagnostics | Free |
| Shipping | Courier (You → OEMatic → You) |
The refurbishment price includes
- Diagnosis in a dedicated test environment
- Replacement of damaged components with original parts
- Final test before and after repair
- 24-month warranty
Additional costs on your side
- Removal and refitting of the module in the car, which you do yourself or commission to a local mechanic
- The cost of courier shipping to OEMatic, or contact us if you want us to arrange collection from you
Repair vs used vs new module — comparison
In practice, the real alternative is a used unit from an advert — virtually nobody buys a new one for ~13,259 zł. It is therefore worth comparing the repair for 1476 zł with a warranty against a used unit for 1500-3000 zł + several hundred złoty for adaptation, i.e. matching the module to the car, but with no warranty on sound.
| Option | Cost | Warranty | Risk | Time |
|---|---|---|---|---|
| OEMatic repair | 1476 zł | 24 months | Zero — if they do not repair it, you do not pay | 1-3 days |
| Used from an advert | 1500-3000 zł +adaptation | 14-day return | High — it may have the same fault | 2-7 days |
| New module (VW/vagsklep) | ~13,259 zł | 24 months (manufacturer's) | Zero — but nobody pays that much for a radio | 1-4 weeks |
Why a used unit is a risk
A used MIB3 module from an advert looks identical to a working one. The seller usually does not test the audio path in a dedicated environment — most often they only check whether the screen powers up. You buy it, fit it, switch it on and the silence is back. You have 14 days to return it (consumer law), but you are left with lost time and shipping costs.
Even if you find a module at a good price, you need to add several hundred złoty for adaptation, i.e. component protection removal, to the price in the advert. Without this, a module from another VIN will not synchronise with your car.
Why not a new module
The price of a new MIB3 (3G5035820A, source: vagsklep.pl) is around 13,259 zł. In practice, very few people pay that much for a radio, as it is an amount comparable to the value of an older car. Repair for 1476 zł restores full functionality and includes a 24-month warranty. Check the current quote.
FAQ — frequently asked questions
7 questions about repairing sound in MIB3 OI MQB Preh — costs, turnaround time, warranty, power amplifier, removal, used unit and compatible VW models.
OEMatic team — 20 years with factory car audio
OEMatic has specialised exclusively in factory radio and navigation systems since 2005. Every MIB3 module is tested in a dedicated environment, on a bench prepared specifically for this series, both before repair and after it has been completed.
The article was prepared by the technical team of OEMatic service.
- Since 2005 — over 20 years of experience in electronics repair
- Factory systems only — no aftermarket devices, i.e. non-factory
- Dedicated test environment — control unit + gateway + display + panel + OBD2
- Original components — no substitutes
- Set price before repair — based on historical repairs, not in an “from… to…” format
- 24-month warranty — on the service performed
