Eros has very weak L channel [resolved]

[Randy morgan]

I received & installed the 2 transistors today, and….now the left channel is totally silent. Ah well, at
least I got to email-meet Mrs Doc B, Eileen who sent the parts. I had high hopes. Not sure what to do
now, kind of losing interest. It’s Not the kit’s fault. As I said previously, I thought I was being careful, methodical & I didn’t feel like I was in a hurry. I do now realize my 66 year old focus and concentration is Nothing like it was when I was younger. I probably should have kept my work time to 90 min, & not 2-3 hours.

[Paul Birkeland]

Did you measure voltages before you tried to listen to your kit?  You really have to do that, as bad voltages mean your kit isn't working and could cause unpredictable consequences if you attempt to use it!

[Randy morgan]

No I did not measure voltages first, thinking the reversed transistors MUST be the (only) problem.
Wrong again. At least readers of this thread can see what Not to do.
Voltages have gone from bad to much worse

The 3 power board #s are the same

Shunt board all essentially the same except OB is 243 (was 227). & kregB 8.2 (was 7.25)

C4S: IA 245 (was 229).   The other readings not listed are normal/unchanged.
        OA 173 (was 227)
        OB 230 (was 108)
         OD 60 (was 101)
         OkB 58 (101)
         OkD 2.51 (1.99)

What a mess. I wonder if I fried the replacement transistors, or even the entire board. I had to apply heat for a long time to wiggle
The new leads into old solder-y holes, though I did spend quite a bit of time trying to clean the holes first.
     With so many crazy readings I’m thinking I should start over,  buy a new kit , everything except the base and transformer. Costs a bit more but less frustrating. Unless I screw it up again.
Hey I have a great idea! I’d love to have an Eros ii with 1:15 sut (my Shelter 901 is 0.5 mv) BUT built by
YOU. Now that would be sweet. My work is just not that good. I’ve built simple amp kits, but this Eros was much more difficult
Ok ok please advise,
& thanks again PB for your time & effort.

[Randy morgan]

Or if I remove the c4s board & just build a new  one, I can send better pix of the 3 sockets & surrounding connections

[Paul Birkeland]

Now you have to go back to the board above the 12AU7 socket and figure out why that has stopped working.  The 220V you should have at IA on the front board is determined by proper operation of the board above the 12AU7, which is now no longer functioning properly.

If you remove both the IA and IB wires on the front PC board and let them poke up into the air, what do you see at OA and OB on the C4S board above the 12AU7 socket?

[Randy morgan]

I’ve read your post 5 times, it’s still confusing. You refer to the ‘front board’, the ‘board above the 12au7 socket’ , the  ‘front pc board’ and ‘the c4s’ board above the 12au7’ even though the c4s is above the 6922
  I see 3 boards, from back (ac plug) to front (inputs) are power supply, shunt reg, and c4s.
 

[Randy morgan]

The shunt reg board is above the 12au7
The c4s board is above the 6922
I think you said the shunt reg board is no longer functioning properly.
You want me to remove IA & IB from the c4s board but ‘what do you see (you mean voltages?) at OA & OB “on the c4s board above the 12au7” Did you mean 6922?

[Paul Birkeland]

Remove the IA and IB wires from the front PC board that's above the front three sockets.

Measure OA and OB on the board above the 12AU7 socket.

[Randy morgan]

OA is 224, OB is 267

[Paul Birkeland]

How about Kreg B?

[Randy morgan]

Kreg B 4.7
Kreg A 3.22

[Paul Birkeland]

It's probably best to send this in for repair at this point or to order new PC boards and parts to populate them, as it seems likely that both boards are having issues.

This is also eligible for our repair service at this point if that's something you'd like to take advantage of.

-PB

[Randy morgan]

I have no confidence in my ability to fix this.
I would like to send it in for repair service. It’s either that or send it to the trash!
Thanks again for your time & patience
Please let me know how to proceed
RM

[Paul Birkeland]

You can e-mail queen(at)bottlehead(dot)com and let her know that you've been working with me on the forum and are requesting the repair service for your Eros and she'll get you setup.

[Randy morgan]

I can’t thank you enough, such a relief. Over & Out
Bottlehead forever!
RM