Hello,
I have an old sony MHC 1600 stereo system that seems to be working fine with the exception of the Display on the main componet assy. Does anyone know where I could find a service manual? I know it is an old obsolete system, but I would like to fix it, if it something simple.
Thanks,
I have an old sony MHC 1600 stereo system that seems to be working fine with the exception of the Display on the main componet assy. Does anyone know where I could find a service manual? I know it is an old obsolete system, but I would like to fix it, if it something simple.
Thanks,
If you have 4V A/C on the filament and -28V or more on most of the pins, the display has probably failed. Manual is here;
SONY HCD-H1600 Service Manual free download, schematics, eeprom, repair info for electronics
Hope that helps.
SONY HCD-H1600 Service Manual free download, schematics, eeprom, repair info for electronics
Hope that helps.
Thank you. I will have to open it up this week and see if I can verify the filament. The display does light up faintly after about 15 minutes of operation. I suspected it was the problem. It is probably impossible to find a replacement new. Is there some boneyard somewhere for old audio/video systems (like a junk yard for cars or planes) on-line or otherwise that might have something like that?
If the display lights up after some time, check power supply for charred pcb, broken solder, faulty component, and other ageing problems.
Gajanan Phadte
Gajanan Phadte
I have had with two MHC-1600 this problems with the same cause: The display-IC needs 32V which is made with a Villarde-cascade from 20V AC. C278 - 47u/50V - is the first cap in this cascade. It was defective on both motherboards. Bacuse the voltage across the cap is around 53V a 50V-type is "programmed" to fail, so for replacement a 63V-type is recommended.
I just wanted to say Thank You for posting this so long ago. My MHC1600 also had a failing display and finally got retired in 2019. I finally got around to taking the plunge today and swapped out the two 47 uF caps on the Main Board (c278 and c279) with fresh 60 V versions and it worked!
Despite best efforts, I still managed to rip the circuit board traces for C278 on both sides, so had to resort to a bodge wire to the power source and soldering to the diode on the other side. It might have been better if I had tried clipping the old wires on the component side and soldering to them instead I guess.
The old bad caps showed none of the usual electrolytic problems of leaks or bulges, but my meter confirmed they were useless.