Help please. Low volume Roksan caspian mk 1

[hixy]

Hello, I have an issue where im getting low volume on my Roksan Amp. I have bassically stripped it down as i want to restore it .Before i get the spray cans out id really like to get the amp working properly.As i really have no clue,where would i start looking.I have a multimeter and i can solder ok .


Thanks in advance

Mick

 

[huggygood]

🙂

 

[hixy]

Thank you for the help, the voltage regulator does it need replacing.You have circled the diagnostic socket im assuming i need to check something 😀

Thanks again

 

[BeyondStupid]

Measure the voltages written on the pcb at those points against ground and check if they are within range 👍

Edit: The regulator has a weird color, could have been too hot.

 

[NickKUK]

I'm looking at the PCB itself - the heatsink holes seem to have been torn, almost like they pulled off the heatsink and adhesive rippled the solder mask off. After the voltages on the test header, the bias for the RHC and LHC are next-door - you could measure the voltages on those too.

 

[NickKUK]

I've also seen the same with -20V and +20V regulators too- they pulled the heatsinks off and tore the PCB. So it's worth checking the traces and continuity and if you're going to restore it.. you may need to find some replacement heatsinks.

 

[hixy]

My Son stored this in his garage.I removed the heat sinks because the nuts holding them are rusty and was going to replace them with new ones.The heat sinks were not soldered to the pcb .Should they be ?

Thank you all for your replies .

 

[BeyondStupid]

The heat sinks were not soldered to the pcb .Should they be ?

Not necessarly, but you should try to gently scrape off the rust. Sometimes they are grounded, and I can see at least one bridge due to rust.

 

[hixy]

arhh ok thank you .

 

[hixy]

ive cleaned the rust of on 2 off the heat sinks and they look really good.The last one as you can see from the picture is covered in yellow goo do i need to remove this also ?

 

[BeyondStupid]

Yes, gently cleaning is the way. The left one at "PSU" lettering could be bridging. But you should also measure the voltages. Ideally you would have done a before and after measurement 🙂