Vintage Synth Repair

--- In vintagesynthrepair@yahoogroups.com, Terje Winther <terje.winther@...> wrote:
>
> Hi,
> Thanks for the info.
> I have justed serviced an OB-8 that showed the same problems regarding  
> power, and especially the bridge rectifier. All black board area like  
> your photos. The OB-8 I had in didn´t hvae the mods/straps like yours,  
> but it did have some other added cables across several of the boards.  
> Very unstable unit, and the mux chips got a little too hot for my  
> taste. It will probably need another run of service to dig further in  
> at the power problems.
> Good luck with yours!
> 
> Terje
> 
> Den 7. juli. 2009 kl. 00.23 skrev gnw:
> 
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> 
> Terje Winther
> terje.winther@...
> http://www.wintherstormer.no/
>
If you're noticing excessive heat on ICs , check the power supply rails. I had a ADCOM CD player, excessive heat on DAC chip. replaced chip but found it was the -5 VDC supply running at -13 (YIKES!)
replaced the -5 reg IC and filter caps . All better now.

Also , check what the IC is driving into. It might be another component with a bad load on the previous IC