Page 1 of 1

Philips UFO 22GF303 turntable

Posted: 06 Mar 2019 20:02
by KolfMAKER
I have recently repaired a Philips UFO 22GF303 turntable. This is not a HiFi tt, but a special design tt. (See picture)
The amplification wasn't working, but after exchanging the two main transistors, it worked perfect.

Now (all of a sudden) the amplification is gone, but sometimes it works. So like 1 out of 10 times it works, but 9 out of 10 it doesn't.

I took out the cartridge (sliding system) and checked the contacts. They are all good.

Any idea what is going on?
Tips are welcome.

Re: Philips UFO 22GF303 turntable

Posted: 12 Mar 2019 06:36
by Wickieleeks
By exchanging the two main transistors (AC187 and AC188) you mean you swapped them or did you replace them for similar ones?

Re: Philips UFO 22GF303 turntable

Posted: 12 Mar 2019 06:48
by Spinner45
KolfMAKER wrote:
06 Mar 2019 20:02
I have recently repaired a Philips UFO 22GF303 turntable. This is not a HiFi tt, but a special design tt. (See picture)
The amplification wasn't working, but after exchanging the two main transistors, it worked perfect.

Now (all of a sudden) the amplification is gone, but sometimes it works. So like 1 out of 10 times it works, but 9 out of 10 it doesn't.

I took out the cartridge (sliding system) and checked the contacts. They are all good.

Any idea what is going on?
Tips are welcome.
Attempting to get an "across the internet" diagnosis of electronics problems is nearly impossible, particularly if the unit has been tampered with.
It's just not reasonable, at best endless specualtion is involved, guessing, etc.
Techs worked from schematic service diagrams, with the unit right in front of them on the bench.
The internet may be a wonderful thing, but it cannot and will not replace the old way of doing things.

Re: Philips UFO 22GF303 turntable

Posted: 17 Mar 2019 11:48
by KolfMAKER
@Wickleleeks
I swapped them for new ones. After that, the turntable did work. There was normal amplification of the sound.
After not having the sound anymore I discovered that one of the wires coming from the cartridge was not properly connected to the PCB. I resoldered both of them to be sure this was not the issue. After that, still no sound. Any suggestion?

@Spinner
Thanks for responding. You are right, it is easier with schematics and the equipment in front of you. Nevertheless, with my 'limited' knowledge and suggestions of experts via forums, I have been able to repair quite some audio equipment already. So bear with me if you like to share a suggestion.