SOny Clock IC492 looses time

Hello everyone,
   As danycrash pointed out, it depends on the supply frequency. But I have the solution now. Do the following carefully. Before starting note that the stupid designer of this clock assumed that we are having a pure sinewave powersupply with constant frequency and even without any power failure. So my solution (I found out by doing some research on this :-) ) will work if you can guarantee continuous 50 HZ power supply That wont be possible in india I am sure.


 1. Open the box (you got 5 screws to remove , two of them hidden behind a body coloured lid at the top). 
 2. Carefully open the case without damaging the switches and dials and other radio settings (remember this is Chinese made). 
 3. Now you need to remove one screw (a black one) to take the circuit board out(with the LED panel).
4. If you turn the pcb , you can see two ICs on it . One among them is sanyo ic Number LM 8562. This is one which controls the clock functionality of the device. 
5. Now you need a little bit of skill. You need to disconnect the Pin number 26 ( if you are not sure how to count the pins of an ic, observe the IC from top so that you can read the 
   Part number written on it and from left to right its the third pin on the top line of this 28 Pin IC) . By using a wire cutter with sharp tip, carefully select that pin and disconnect it.
    (you can desolder it and pull also if you know how to use a soldering iron) using a nose plier pull the pin and bend it sidewards. 
6. now the IC is in mode 12 Hr with 50 HZ. If you want to make it 24 Hr , then you need to ground the pin instead of openig it. I didnt try this. 


7. So carefully replace the PCB and the device back cover with properly screwed in.




Now your clock is synch with Indian power supply of 50 HZ ( remember you still need to used  220 to 110 volt adapter) .


Since our power supply varies from 48 Hz to 50.5 Hz, you can expect the clock may lag around 1 minutes per hour. If you have an invertor with 50 HZ constant supply, 
then it should be accurate. 
  Even in US, the supply frequency varies. I dont know why the circuit designer did like this. 
  I have another one ICF-C318, which is accurate till today ( guess its using normal clock ciruits not depending on the power supply)
  
 Hope your device is working fine now.
 
 regards,
 Anand KRishnan
 Bangalore Hello everyone,    As danycrash pointed out, it depends on the supply frequency. But I have the solution now. Do the following carefully. Before starting note that the stupid designer of this clock assumed that we are having a pure sinewave powersupply with constant frequency and even without any power failure. So my solution (I found out by doing some research on this :-) ) will work if you can guarantee continuous 50 HZ power supply That wont be possible in india I am sure.
 1. Open the box (you got 5 screws to remove , two of them hidden behind a body coloured lid at the top).   2. Carefully open the case without damaging the switches and dials and other radio settings (remember this is Chinese made).   3. Now you need to remove one screw (a black one) to take the circuit board out(with the LED panel). 4. If you turn the pcb , you can see two ICs on it . One among them is sanyo ic Number LM 8562. This is one which controls the clock functionality of the device.  5. Now you need a little bit of skill. You need to disconnect the Pin number 26 ( if you are not sure how to count the pins of an ic, observe the IC from top so that you can read the     Part number written on it and from left to right its the third pin on the top line of this 28 Pin IC) . By using a wire cutter with sharp tip, carefully select that pin and disconnect it.     (you can desolder it and pull also if you know how to use a soldering iron) using a nose plier pull the pin and bend it sidewards.  6. now the IC is in mode 12 Hr with 50 HZ. If you want to make it 24 Hr , then you need to ground the pin instead of openig it. I didnt try this. 
7. So carefully replace the PCB and the device back cover with properly screwed in.

Now your clock is synch with Indian power supply of 50 HZ ( remember you still need to used  220 to 110 volt adapter) .
Since our power supply varies from 48 Hz to 50.5 Hz, you can expect the clock may lag around 1 minutes per hour. If you have an invertor with 50 HZ constant supply,  then it should be accurate.    Even in US, the supply frequency varies. I dont know why the circuit designer did like this.    I have another one ICF-C318, which is accurate till today ( guess its using normal clock ciruits not depending on the power supply)     Hope your device is working fine now.    regards,  Anand KRishnan  Bangalore