Yamaha vintage CR-620 receiver - no sound but power and signal - UK Vintage Radio Repair and Restoration Discussion Forum

RDWER123 · 21st Jan 2023, 5:55 pm

Hi all

Bought this today for £20 with a month's warranty. The casing is excellent, it powers up and receives an AM and FM signal. However, there is no sound coming out of the speakers that I've hooked up to it.

I opened it up and it was filthy, covered in dust as you can see from the photo. I've carefully cleaned it all up and sprayed a little contact cleaner here and there, but still nothing.

Is there anything I could do, bearing in mind my skill-set is very low, to get this going again because it looks great and looking at old reviews, I don't really want to take it back for a refund unless I have to.

I can see various fuses on the circuit board, perhaps change them?

Thanks all

Trevor · 21st Jan 2023, 6:34 pm

some Yamaha units has a pair of links between the pre amp and power amp check on the back or please show us a picture of the rear
Trev

RDWER123 · 21st Jan 2023, 6:48 pm

Thanks, here's the back. Can't see any links.

I'll try to post clearer pictures tomorrow, the light is terrible now.

cmjones01 · 21st Jan 2023, 7:06 pm

I see it has on/off switches for speakers A and B. Are they in the correct positions?

RDWER123 · 21st Jan 2023, 7:31 pm

Yes, I've tried every combination of A/B speakers to no avail

Roger Ramjet · 21st Jan 2023, 7:58 pm

Does it have a headphone socket to try for audio ?

Rog

John123 · 21st Jan 2023, 11:08 pm

Do check all fuses for continuity. On power-up, you should hear the distinct sound of a speaker protection relay kick-in (usually after a few seconds). If you do not, there may be a problem in the power amp section, or in the actual protection circuitry, itself.

The twin headphone sockets are under the little plastic 'Reserved For..' plaque. Ignore the spiel and use whatever headphones you like! If you get sound through these, then at least you'll know if the power amp is OK.

It's easy to rule-out the pre-amp section, as you can feed the 'Rec Out' from one of the tape loops to another amplifier, thus enabling you to hear the tuner (set both the 'Rec Out' and 'Input' selectors to 'Tuner', and set 'FM Muting' to 'Off').

RDWER123 · 22nd Jan 2023, 12:10 pm

Thanks all, really appreciate your help

Nothing from the headphone sockets, either A or B, didn't realise the 'RESERVED FOR' badge was covering the sockets!

I'll try the tape out to another amp suggestion, but I think it's had it, so I'm either going to see if a professional can fix it or I'll take it back for a refund. But I really don't want to because it looks brilliant and would slot in beautifully with my other 70s gear.

Roger Ramjet · 22nd Jan 2023, 2:08 pm

It does not seem to be a basket case so I would hang on to it if it was mine.... just for the looks alone ! Maybe you could negotiate a £10.00 refund from the seller ?

Roger

RDWER123 · 22nd Jan 2023, 2:12 pm

Yes, for twenty quid I'll hang on to it. I know someone who might be able to fix it, although he's more of a valves man. I wonder if Yamaha themselves are prepared to look at old kit? I doubt it. It does look truly wonderful.

RDWER123 · 22nd Jan 2023, 2:19 pm

I mean, just look at it! Wonderful.

Radio Wrangler · 22nd Jan 2023, 2:41 pm

Beautiful outside, but quite ordinary inside. They knew how to make things sell. But Yamaha gear was generally good.

At that price, it's well worth fixing. You just have to find someone who can.

David

Analogue man · 23rd Jan 2023, 12:48 pm

I see from the rear photograph that it appears to me that the speaker cables have been connected to the wrong connectors if I'm right the cable should be connected to the red and black connectors that are in a row i.e. the top row or the bottom row.

Station X · 23rd Jan 2023, 1:08 pm

Looks like the top row is for Left Speakers and the bottom row is for Right Speakers. A clearer, close up, in focus image of the connections is needed.

Station X · 23rd Jan 2023, 1:16 pm

I was wrong, but the comments in my previous post still apply. Is that screened speaker cable?

ms660 · 23rd Jan 2023, 1:39 pm

A couple of shots of the back of one.

Lawrence.

Analogue man · 24th Jan 2023, 1:29 pm

Having looked again at the photo of the rear of the receiver with the speakers connected and also looked at the photo in the last post and Graham's diagram it does appear that you have the speakers connected to the red terminal on A and the red terminal on B, this won't work.

Trevor · 24th Jan 2023, 3:50 pm

I agree re the spk connections having said that the headphones should have worked
Trev

DMcMahon · 24th Jan 2023, 11:01 pm

Quote:

Originally Posted by Analogue man

Having looked again at the photo of the rear of the receiver with the speakers connected and also looked at the photo in the last post and Graham's diagram it does appear that you have the speakers connected to the red terminal on A and the red terminal on B, this won't work.

Maybe due to a combination of my eyesight + the not great quality of the photo in Post 3 I do not see that myself.

David

vidjoman · 24th Jan 2023, 11:29 pm

One of the photos shows what looks like a 1/4 inch to 3.5mm adaptor plugged into a headphone socket on the front of the panel. That might kill the speaker outputs.

21st Jan 2023, 5:55 pm	#1
RDWER123 Triode Join Date: Jun 2021 Location: Belfast, Northern Ireland, UK. Posts: 36	Yamaha vintage CR-620 receiver - no sound but power and signal Hi all Bought this today for £20 with a month's warranty. The casing is excellent, it powers up and receives an AM and FM signal. However, there is no sound coming out of the speakers that I've hooked up to it. I opened it up and it was filthy, covered in dust as you can see from the photo. I've carefully cleaned it all up and sprayed a little contact cleaner here and there, but still nothing. Is there anything I could do, bearing in mind my skill-set is very low, to get this going again because it looks great and looking at old reviews, I don't really want to take it back for a refund unless I have to. I can see various fuses on the circuit board, perhaps change them? Thanks all Attached Thumbnails

21st Jan 2023, 6:34 pm	#2
Trevor Octode Join Date: Aug 2006 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 1,082	Re: Yamaha vintage CR-620 receiver - no sound but power and signal some Yamaha units has a pair of links between the pre amp and power amp check on the back or please show us a picture of the rear Trev

21st Jan 2023, 6:48 pm	#3
RDWER123 Triode Join Date: Jun 2021 Location: Belfast, Northern Ireland, UK. Posts: 36	Re: Yamaha vintage CR-620 receiver - no sound but power and signal Thanks, here's the back. Can't see any links. I'll try to post clearer pictures tomorrow, the light is terrible now. Attached Thumbnails

21st Jan 2023, 7:06 pm	#4
cmjones01 Nonode Join Date: Oct 2008 Location: Warsaw, Poland and Cambridge, UK Posts: 2,679	Re: Yamaha vintage CR-620 receiver - no sound but power and signal I see it has on/off switches for speakers A and B. Are they in the correct positions? __________________ What's going on in the workshop? http://martin-jones.com/

21st Jan 2023, 7:31 pm	#5
RDWER123 Triode Join Date: Jun 2021 Location: Belfast, Northern Ireland, UK. Posts: 36	Re: Yamaha vintage CR-620 receiver - no sound but power and signal Yes, I've tried every combination of A/B speakers to no avail

21st Jan 2023, 7:58 pm	#6
Roger Ramjet Heptode Join Date: Feb 2022 Location: Leicestershire, UK. Posts: 690	Re: Yamaha vintage CR-620 receiver - no sound but power and signal Does it have a headphone socket to try for audio ? Rog

21st Jan 2023, 11:08 pm	#7
John123 Heptode Join Date: Jan 2007 Location: Luton, Bedfordshire, UK. Posts: 891	Re: Yamaha vintage CR-620 receiver - no sound but power and signal Do check all fuses for continuity. On power-up, you should hear the distinct sound of a speaker protection relay kick-in (usually after a few seconds). If you do not, there may be a problem in the power amp section, or in the actual protection circuitry, itself. The twin headphone sockets are under the little plastic 'Reserved For..' plaque. Ignore the spiel and use whatever headphones you like! If you get sound through these, then at least you'll know if the power amp is OK. It's easy to rule-out the pre-amp section, as you can feed the 'Rec Out' from one of the tape loops to another amplifier, thus enabling you to hear the tuner (set both the 'Rec Out' and 'Input' selectors to 'Tuner', and set 'FM Muting' to 'Off'). __________________ Regards, John

22nd Jan 2023, 12:10 pm	#8
RDWER123 Triode Join Date: Jun 2021 Location: Belfast, Northern Ireland, UK. Posts: 36	Re: Yamaha vintage CR-620 receiver - no sound but power and signal Thanks all, really appreciate your help Nothing from the headphone sockets, either A or B, didn't realise the 'RESERVED FOR' badge was covering the sockets! I'll try the tape out to another amp suggestion, but I think it's had it, so I'm either going to see if a professional can fix it or I'll take it back for a refund. But I really don't want to because it looks brilliant and would slot in beautifully with my other 70s gear.

22nd Jan 2023, 2:08 pm	#9
Roger Ramjet Heptode Join Date: Feb 2022 Location: Leicestershire, UK. Posts: 690	Re: Yamaha vintage CR-620 receiver - no sound but power and signal It does not seem to be a basket case so I would hang on to it if it was mine.... just for the looks alone ! Maybe you could negotiate a £10.00 refund from the seller ? Roger

22nd Jan 2023, 2:12 pm	#10
RDWER123 Triode Join Date: Jun 2021 Location: Belfast, Northern Ireland, UK. Posts: 36	Re: Yamaha vintage CR-620 receiver - no sound but power and signal Yes, for twenty quid I'll hang on to it. I know someone who might be able to fix it, although he's more of a valves man. I wonder if Yamaha themselves are prepared to look at old kit? I doubt it. It does look truly wonderful.

22nd Jan 2023, 2:19 pm	#11
RDWER123 Triode Join Date: Jun 2021 Location: Belfast, Northern Ireland, UK. Posts: 36	Re: Yamaha vintage CR-620 receiver - no sound but power and signal I mean, just look at it! Wonderful. Attached Thumbnails

22nd Jan 2023, 2:41 pm	#12
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,901	Re: Yamaha vintage CR-620 receiver - no sound but power and signal Beautiful outside, but quite ordinary inside. They knew how to make things sell. But Yamaha gear was generally good. At that price, it's well worth fixing. You just have to find someone who can. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

23rd Jan 2023, 12:48 pm	#13
Analogue man Hexode Join Date: Dec 2020 Location: Raunds, Northamptonshire, UK. Posts: 355	Re: Yamaha vintage CR-620 receiver - no sound but power and signal I see from the rear photograph that it appears to me that the speaker cables have been connected to the wrong connectors if I'm right the cable should be connected to the red and black connectors that are in a row i.e. the top row or the bottom row. __________________ Graham

23rd Jan 2023, 1:08 pm	#14
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Yamaha vintage CR-620 receiver - no sound but power and signal Looks like the top row is for Left Speakers and the bottom row is for Right Speakers. A clearer, close up, in focus image of the connections is needed. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

23rd Jan 2023, 1:16 pm	#15
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Yamaha vintage CR-620 receiver - no sound but power and signal I was wrong, but the comments in my previous post still apply. Is that screened speaker cable? Attached Thumbnails __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

23rd Jan 2023, 1:39 pm	#16
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Yamaha vintage CR-620 receiver - no sound but power and signal A couple of shots of the back of one. Lawrence. Attached Thumbnails Last edited by ms660; 23rd Jan 2023 at 1:58 pm. Reason: clarify

24th Jan 2023, 1:29 pm	#17
Analogue man Hexode Join Date: Dec 2020 Location: Raunds, Northamptonshire, UK. Posts: 355	Re: Yamaha vintage CR-620 receiver - no sound but power and signal Having looked again at the photo of the rear of the receiver with the speakers connected and also looked at the photo in the last post and Graham's diagram it does appear that you have the speakers connected to the red terminal on A and the red terminal on B, this won't work. __________________ Graham

24th Jan 2023, 3:50 pm	#18
Trevor Octode Join Date: Aug 2006 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 1,082	Re: Yamaha vintage CR-620 receiver - no sound but power and signal I agree re the spk connections having said that the headphones should have worked Trev

24th Jan 2023, 11:29 pm	#20
vidjoman Dekatron Join Date: Jun 2013 Location: East Sussex, UK. Posts: 3,326	Re: Yamaha vintage CR-620 receiver - no sound but power and signal One of the photos shows what looks like a 1/4 inch to 3.5mm adaptor plugged into a headphone socket on the front of the panel. That might kill the speaker outputs.