It seems to oscillator section is out on my radio. Delco 16164325. With power the digital clock reads only 1:00 and the radio is locked on 98.1 Mhz on the display. The control buttons change the display, but you cannot adjust any of the settings. On board "167 525" the 33 Ohm 2 Watt resistor has overheated, but still reads 33 Ohms (needs replaced). This resistor goes to what appears to be the oscillator circuit through a transistor in the vicinity of an 8 pin chip that I suspect is the clock chip, but I cannot read the numbers on these chips. Is a schematic available for me to troubleshoot my problem. Any help would be appreciated.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
The purpose of a crystal is to regulate an oscillator circuit to the frequency of the crystal. It can also be used to filter a particular frequency from a mixed signal.
In an oscillator circuit, if the crystal is defective, the oscillator might still be working in an unregulated way or it might not work at all. If an oscillator circuit does not work it is just as likely to be one or more of the other components in the circuit that are faulty or a lack of supply current.
While there are probably modern solutions to the testing of a crystal-controlled oscillator or clock circuit, the original method would be to investigate the current supply to the circuit and check for function using an oscilloscope or a frequency counter. If the circuit seems ok but not oscillating the cystal is probably the easiest component to remove for testing, though it is probably easier and cheaper to simply replace it.
There are dedicated crystal testers available or it can be fitted to a known good oscillator circuit and checked as above. If the crystal is found to be ok (which is likely) the other components must be investigated/tested/replaced, which would be a highly specialised task and likely to be expensive.
Unless your motherboard is something really special and very expensive without many "miles on the clock" it is more practical, economic and convenient to consider the motherboard as a throw-away unit.
Hello. I've been there before. Go to a well known autoparts store and look into a doit your self service manuall and look into the radio-audio section. Good Luck.
8-21-2021 FM reception across the band was degrading in sensitivity over time & now barely gets 2 very strong stations . I'm an Electrical Engineer radio designer. I intuited that the tuner's frequency synthesized oscillator could be corrupted / unstable causing a noise that degrades sensitivity. Today I confirmed that the oscillator is indeed unstable from digital noise in the synthesis mechanism. worse at the 88 mhz end than the 108 mhz end. This typical action for a synthesizer. Hope when open it up a simple degraded resisitor or capacitor component in the synthesizer will reveal irtself. Elsewhere someone reported contaminant on the PCB which is also a likely cause of degredation. Perhaps a leaky back-up memory AA battery dripped "acid" on the PCB and just needs to be cleaned ? jerry at jdm labs
8.22. I measured the the spectrum of the FM tuner's superheterodyne oscillator which should be a single pure frequency . Instead at the 2 ends of the band the spectrum plots show it has multiple frequencies spaced about 40 kiloHertz apart which becomes a 40 kilohertz "noise" interfering with the desired signal . The frequency synthesizer is a Sanyo chip LC72131 and I'm searching for the application schematic diagram of the Recepter ( only owners manual is available) to identify which components may have failed or shifted. Hopefully the chip is ok but need to figure that out too.
Hello
If the picture is correct in black and white mode and sound is Ok, your TVs chroma section is in trouble. At present sets, this section consists of an Ic. That Ic may be not working. There are many reason for which chroma section cannot work. Consult an experienced technican to rectify the trouble. There is an oscillator section inside the chroma Ic which receives its oscillations from an ouside crystal oscillator, usually oscillates at a frequency of 4.43361879Mhs or 8.86Mhz or may differ its frequency according to the circuit designs of that tv. Your technician will detect it and rpace the same if needs. You yourself cannot detect the exact point of fault. It need digital multimeter which can count frequency also.
Check the swithed mode power supply section. Some sets uses Ics for control the power regulation, while others uses transistors as oscillators and choppers. If the power to the oscillator section of the SMPS is absent, the supply system won't wake up. So many reasons are there. You just check the resistor, usually connected from main DC rectified supply, to energise the oscillator section of the SMPS. In most sets it may be two resistors in serial, usually 270k 1W*2. If any one of this get opened, the power supply will not start up. Check it first and preceed. If the set uses Ic as regulator controller, check the positive supply voltage at the respective pin of the Ic.
u have a bad MW tuner section. this is a transistor radio probably using MW oscillator coils and IF transformers. I suspect the IF transformer or related components cause misalignment hence no audio output from the radio. just noise.
HI, THE FIRST THING YOU HAVE TO LOOK FOR IS WHAT KIND OF ADAPTER 9V 1AMP YOU SHOULD HAVE FOR THAT PARTICULAR RADIO AND ANTENNA FOR SW AND FM SHOULD BE CONNECTED.IT MUST BE THE ADAPTER THAT'S ON THE OUTS NOT ENOUGH VOTAGE TO POWER THE RADIO.
It sounds like you have an integrated power supply issue. This type of supply truns on the horizontal oscillator which provides excitation to the Horizontal Output stage which in turn work with the HV section of the TV the extra LV levels are supplied by this interaction. That tsss noise might be the oscillator trying to work or the startup circuit trying to work. I would check the Horizontal and HV sections for failed components.
×