Hoping to get some guidance on repairing my old GF8585HB. Owned since I was 15; and worked OK before. One day thought it would be a good idea to power off the wrong DC supply one day. Heard a horrible pop sound; and it hasn't worked since (surprise surprise). It lived in a box for 15 years until today - and here I am trying to resurrect it. Basically I'm trying to get it to power up off of AC power to no avail. Troubleshooting so far: -Have replaced the fused on the power supply circuit -Have made a jumper for a burnt out track on the power supply circuit (yellow wire in pictures). -Checked all Caps and Diodes on the power circuit, and they seem to be working OK. -Tested Voltage from the Orange and Black Jumpers that connect the power supply to the main board. So after all that; I'm getting 12.7v from the power supply board into the main board. But still no signs of life, except for a very subtle bump to the VU needle each time I change the mode switch. Have tried all settings (phono/radio/tape) with no success. Anyone have any ideas of what would be the next logical step? Seems like power supply circuit is running again (but is 12.7V the correct voltage)?
Hello on the net I found this scheme ... in the second photo I show you that the phono tape radio switch is divided into 8 sections ... probably since it has been stationary for a long time will have oxidized .... https://www.eserviceinfo.com/downloadsm/21927/Sharp_GF-8585.html https://elektrotanya.com/sharp_gf-8585x_sch.jpg/download.html
Hmm, I did actually blast this switch with cleaner and switch back and forth alot. I would think, even if the switch was dirty, I'd still get some sign of life (a crackle maybe?). But getting nothing at all, from either radio or Tape functions
Since you have a meter I would start looking at some voltages around the main board. IC203 looks to be the audio amp, and the circuit diagram helpfully shows what voltages you would expect to find there. Don't dismiss simple things. I recently saw a Youtube video in which someone spent lots of time trying to find a fault on an old VCR only to find it was simply a bad connection on the PSU connector where it plugged into the main board.
Hello... Put the switch on Tape ... Starting from the red point that and the output of the power supply unit test on the transient Q209 (Blue) if you have voltage or on the pin 10 of IC 203..in this way we try section H of the switch Forgot... play prizes like i want to listen to a tape
