Rotel 820AX problem - any known issues?

[rotelmark]

Hi

I'm after some advice on a Rotel 820AX that I've just bought. Ebay, excellent condition but not tested - I know, I should know better.

Anyway, turning it on and nothing until the volume was turned fully up when I can hear quiet and 'noisy' music. Same through all inputs, and both sets of speaker outputs.

I've opened it up and there is no sign of damage to any components. No obvious leaks from capacitors, no obviously blown transistors or resistors, no brown patches anywhere.

It is however quite dusty and there is the remains of a couple of smallish beetles.

One fuse has blown. (F601)

I'm going to replace the fuse and see what happens, but I thought I'd ask the question, are there any well known issues with this amp?

I'm assuming that the fact that I hear anything is good, and it is likely that the fuse is the supply to the power amp part of the circuit. I'm going to look for a service manual and see if I can find circuit diagrams and schematics.

Suggestions welcome.

thanks

Mark

[homemodder]

Originally Posted by rotelmark

Hi

I'm after some advice on a Rotel 820AX that I've just bought. Ebay, excellent condition but not tested - I know, I should know better.

Anyway, turning it on and nothing until the volume was turned fully up when I can hear quiet and 'noisy' music. Same through all inputs, and both sets of speaker outputs.

I've opened it up and there is no sign of damage to any components. No obvious leaks from capacitors, no obviously blown transistors or resistors, no brown patches anywhere.

It is however quite dusty and there is the remains of a couple of smallish beetles.

One fuse has blown. (F601)

I'm going to replace the fuse and see what happens, but I thought I'd ask the question, are there any well known issues with this amp?

I'm assuming that the fact that I hear anything is good, and it is likely that the fuse is the supply to the power amp part of the circuit. I'm going to look for a service manual and see if I can find circuit diagrams and schematics.

Suggestions welcome.

thanks

Mark

There arent any issues with these amps, Rotels are very reliable but dont take certain abuses well. The blown fuse will tell you that something has gone wrong. I wouldnt just replace the fuse and switch it on if I were you, you may cause further damage if something did go wrong. Test the output transistors and their drivers first, actually Id test all transistors first to make sure they arent blown before powering on, there arent that many. Also check the powersupply rectifier. Due to its age it would be wise to exchange the power supply caps.

[rotelmark]

Thanks for the comments.

I was hoping that the dust/insects might be responsible for a short. But I'll get some new fuses ordered and have a look at the components you suggest.

thanks

Mark