Mitsubishi Z20 Upright play Hi-Fi - UK Vintage Radio Repair and Restoration Discussion Forum

nigelr2000 · 31st Dec 2019, 1:04 pm

I had one of these in for repair so started on it today. I have a muting problem that came down to the analogue input control chip so ordered another. The thing is when I tried to find various resistors to check I had trouble finding them, that is until I realised they are built into the PCB. It's 2 layer with holes through from top to bottom and all the resistors are on there own tracks, just a black smudge between two squares. All the resistors are marked PR*** which I assume is printed resistor.

I can't recall seeing this style before, sort of early surface mount. Anyone else seen it on any other bits of kit ?

samjmann · 1st Jan 2020, 5:56 pm

Hello,

Yes, I've seen this a few times over the years. The one that springs to mind is a Sharp 80's boom-box, possibly a GF-8585. I found it impossible to solder the 'end-tags' of the printed resistors. All I could do was a point-to-point wiring of an 1/4 watt resistor to fix the board. As far as I know the user has had no more problems with it, so hopefully no more will go high value.

All the best for the New Year, SJM.

31st Dec 2019, 1:04 pm	#1
nigelr2000 Heptode Join Date: Nov 2008 Location: North Walsham, Norfolk, UK. Posts: 900	Mitsubishi Z20 Upright play Hi-Fi I had one of these in for repair so started on it today. I have a muting problem that came down to the analogue input control chip so ordered another. The thing is when I tried to find various resistors to check I had trouble finding them, that is until I realised they are built into the PCB. It's 2 layer with holes through from top to bottom and all the resistors are on there own tracks, just a black smudge between two squares. All the resistors are marked PR*** which I assume is printed resistor. I can't recall seeing this style before, sort of early surface mount. Anyone else seen it on any other bits of kit ? Attached Thumbnails __________________ https://www.facebook.com/gntrading

1st Jan 2020, 5:56 pm	#2
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, UK. Posts: 648	Re: Mitsubishi Z20 Upright play Hi-Fi Hello, Yes, I've seen this a few times over the years. The one that springs to mind is a Sharp 80's boom-box, possibly a GF-8585. I found it impossible to solder the 'end-tags' of the printed resistors. All I could do was a point-to-point wiring of an 1/4 watt resistor to fix the board. As far as I know the user has had no more problems with it, so hopefully no more will go high value. All the best for the New Year, SJM.