Problems with C-70

Hey guys,

I've got a C-70 thats been running like a champ for about a year since I bought it. I absolutely love it! Unfortunately.... it's giving me some problems.

It has a weak/static output on both of the channels, it is slightly worse on the left. Now, I opened it up and look for all of the obvious things. I can't find any bad solder joints from a general look over (top and bottom of the board). I also can't find any obviously damaged or burnt components.

I am suspecting the main output relays. These are the relays that are in series with the main output jacks. The reason I am suspecting these is because if I lightly tap on these two relays with a screw driver while the amp is on, it fixes the problem. Though, not permanently. Now, I cleaned one of these relays about 4 months ago when a similar issue occured on only the left channel. I was thinking about replacing the relays. However, I can't find any of the Matsushita HB2YD-DC24V that is in it. Do you guys have tips on where to get a drop in replacement or really good steps on cleaning the ones on the board?

Thanks in advance!

Daniel

I'm sure a real tech will weigh in here soon, but for now, my suggestion is to consider cleaning the switches and pots. There's a thread about using DeOxit that you may find helpful.

good luck

I don't think it has to do with any of the switches or pots. The operation of all of the switches and pots seems to have no effect on it. However as I stated in my first post, I can lightly tap the relays during operation and temporarily fix the problem.

Daniel

A parts unit C-50 has about 6 of them in it. Check your solder connections on the one you suspect being flaky..

I checked the underside of the board and the solder connections on the relays look perfect. I have also noted that pushing on the top cover of the relays affects the output of the main out and inverted output. That makes me think a bad solder joint. But, the solder joints are perfect!!!!

Anyone have some spare functional relays out of say a parts c-50 for sale????

thefluffy said:

I checked the underside of the board and the solder connections on the relays look perfect. I have also noted that pushing on the top cover of the relays affects the output of the main out and inverted output. That makes me think a bad solder joint. But, the solder joints are perfect!!!!

Anyone have some spare functional relays out of say a parts c-50 for sale????

Click to expand...

I'd reflow the solder connections.Looks can be decieving..:yes:

contact problems with the relays and there are allot in a c 70