Philips GA312 phono output hum

[Gigant]

Hello dear DIY members,

iam new to this forum and its my first thread or a cry for help i should say. Ill try to explain my very common but not easy problem. Im trying to refurbish Philips GA312 turntable. Ive resoldered 5pin connection to standard RCA. Im now experiencing a ground hum and a weaker sound signal on one of two channels. First thought was that the solder points might have been faulty so resoldered everything from cartridge fitting side to tonearm wire/RCA connection. Still getting same results. Refitted/checked tonearm wire for continuity, all is fine and working. Resoldered black (main ground) wire at cartridge side from unused fifth (center) slide connection to tonearm where cables enter tonearm. Still the same. If anyone has experienced same or similar problem, please give me an advise where did i go wrong. Thanks in advance. Attaching some photos for a brief:
Imgur: The magic of the Internet

 

[JonSnell Electronic]

Check your wiring. See fig. 7 for the correct wiring. Note the ground points.
Pins 3 & 5 are your left and right.
Service Manual - Philips 22 GA 312 00R - Turntable -- Download free service manuals

 

[Gigant]

Thanks for a manual. All of my wiring is correct. Just to be sure, are (green)GN, Black and (blue)LG soldered together at the RCA connection point?

 

[korpberget]

Poor contact on the pickup sled? Common problem on these players. Tried another pickup?

 

[Gigant]

Yes, same problem with dofferent pickup. Should i try soldering directly onto sled contacts then?

 

[Kay Pirinha]

Thanks for a manual. All of my wiring is correct. Just to be sure, are (green)GN, Black and (blue)LG soldered together at the RCA connection point?

If I've got you right, you've been replacing the original DIN cable or plug with a pair of RCA ones? Then you should remove the ground bridge, connect LG (blue) to the left channel shielding, RG (green) to the right channel shielding, and black to a separate lead that has to be connected to your amplifier's case.
Please check that your cartridge is connected properly and that there's no mix-up between the hot and the ground connection of one channel.
Best regards!

 

[Gigant]

Thanks Kay, will double check and let you know how it went. Just to be sure, it shows continuity between all 5 wires when connected to phono pre-amp or phono input on the integrated amplifier. They’re separate hot wires when RCA plugs disconnected. Will confirm again and big thanks for replies!

 

[Gigant]

Thank You all for quick responses. Had two wires switched, there was a mix-up between hot and ground wires. Guess a case closed then. Will go enjoy some vinyl now. Wish you a great weekend!