A77 Input issues. - UK Vintage Radio Repair and Restoration Discussion Forum

NorfolkDaveUK · 26th Oct 2018, 2:25 pm

My A77 is doing some weird stuff again .

When I have both record switches in , all is well . Both sides have input .
When I have both record switches out , input is only on the left side , both audibly and in the VU`s .

Any ideas ?

Michael Maurice · 26th Oct 2018, 7:18 pm

I would think the switches are faulty, its the same signal, they are added or crossed over depending on how they're set.

NorfolkDaveUK · 26th Oct 2018, 10:27 pm

Hi bud , I`ve changed the switches so I don`t think thats it , thats was my first thought too so I changed them for known good ones . On this model they cross over so channel one works channel two when you have them in the out position . I`ll go over the switches again but I`m pretty sure thats not it . Bit weird though huh .

Michael Maurice · 26th Oct 2018, 11:31 pm

Cracked track on the PCB? Cant see it can be anything else.

NorfolkDaveUK · 27th Oct 2018, 3:19 am

found it , there was a resistor that was only soldered in one end , all back to normal .

g0hze snowy · 1st Nov 2018, 9:35 am

Hah the dreaded dry joint problem, should stick them in a tin then they will smoke much better, sorry my idea of levity.

NorfolkDaveUK · 1st Nov 2018, 11:32 am

I think the person that changed that resistor did , it wasn`t a dry joint, it was only soldered in one end ...lol...i think up to that point it was working on will more than anything ...hehe

barrymagrec · 1st Nov 2018, 12:22 pm

I did find a fairly dry joint in the bottom of a Leevers Rich once - the studio owner said "Oh yes I thought I was missing one in a session a couple of weeks ago..."

NorfolkDaveUK · 1st Nov 2018, 1:23 pm

hahah ....amazing

26th Oct 2018, 2:25 pm	#1
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	A77 Input issues. My A77 is doing some weird stuff again . When I have both record switches in , all is well . Both sides have input . When I have both record switches out , input is only on the left side , both audibly and in the VU`s . Any ideas ?

26th Oct 2018, 7:18 pm	#2
Michael Maurice Moderator Join Date: Feb 2006 Location: Wembley, Middlesex Posts: 7,222	Re: A77 Input issues. I would think the switches are faulty, its the same signal, they are added or crossed over depending on how they're set. __________________ Forum Moderator http://www.michaelmauricerepairs.co.uk/

26th Oct 2018, 10:27 pm	#3
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: A77 Input issues. Hi bud , I`ve changed the switches so I don`t think thats it , thats was my first thought too so I changed them for known good ones . On this model they cross over so channel one works channel two when you have them in the out position . I`ll go over the switches again but I`m pretty sure thats not it . Bit weird though huh .

26th Oct 2018, 11:31 pm	#4
Michael Maurice Moderator Join Date: Feb 2006 Location: Wembley, Middlesex Posts: 7,222	Re: A77 Input issues. Cracked track on the PCB? Cant see it can be anything else. __________________ Forum Moderator http://www.michaelmauricerepairs.co.uk/

27th Oct 2018, 3:19 am	#5
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: A77 Input issues. found it , there was a resistor that was only soldered in one end , all back to normal .

1st Nov 2018, 9:35 am	#6
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 333	Re: A77 Input issues. Hah the dreaded dry joint problem, should stick them in a tin then they will smoke much better, sorry my idea of levity.

1st Nov 2018, 11:32 am	#7
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: A77 Input issues. I think the person that changed that resistor did , it wasn`t a dry joint, it was only soldered in one end ...lol...i think up to that point it was working on will more than anything ...hehe

1st Nov 2018, 12:22 pm	#8
barrymagrec Octode Join Date: Dec 2017 Location: Morden, Surrey, UK. Posts: 1,557	Re: A77 Input issues. I did find a fairly dry joint in the bottom of a Leevers Rich once - the studio owner said "Oh yes I thought I was missing one in a session a couple of weeks ago..."

1st Nov 2018, 1:23 pm	#9
NorfolkDaveUK Banned Join Date: May 2018 Location: Norwich, Norfolk, UK. Posts: 605	Re: A77 Input issues. hahah ....amazing