Bottlehead Forum

Bottlehead Kits => Eros Phono => Topic started by: last lemming on February 22, 2021, 03:00:20 PM

Title: Help. Can’t get past the power supply test. [mostly resolved]
Post by: last lemming on February 22, 2021, 03:00:20 PM

I’ve double checked everything and my solder joints and direction of all components look correct. My test on the power transformer came up correct, but when I test the +6.3v and -6.3v I get 13.2v. What do I do?

Title: Re: Help. Can’t get past the power supply test.
Post by: Paul Birkeland on February 22, 2021, 03:06:32 PM

Can you post some photos of the top and bottom of the power supply board?  I would be willing to bet you have some cold solder joints and the regulator isn't doing any regulating.

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 22, 2021, 03:29:22 PM

this is where I am so far

Title: Re: Help. Can’t get past the power supply test.
Post by: Paul Birkeland on February 22, 2021, 03:38:25 PM

Those are teeny, is there any way to get something a bit bigger?

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 22, 2021, 03:56:05 PM

hope these are better

Title: Re: Help. Can’t get past the power supply test.
Post by: Paul Birkeland on February 22, 2021, 04:22:34 PM

Can you confirm that there's a 1085 regulator on the PC board and not an MJE5731A?

You could certainly reheat all your solder joints, but they don't look like I would expect them to in order to end up with no regulation.

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 22, 2021, 04:27:03 PM

Are you talking about the two Cree 1060’s?

Title: Re: Help. Can’t get past the power supply test.
Post by: Paul Birkeland on February 22, 2021, 04:27:33 PM

No, the three legged regulator that mounts to the heatsink.

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 22, 2021, 04:29:29 PM

Oh yeah. Yes that is what is on there

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 22, 2021, 04:30:33 PM

Would a bad connection at T7, T9 or T11 or T12 do this?

Title: Re: Help. Can’t get past the power supply test.
Post by: Paul Birkeland on February 22, 2021, 04:33:53 PM

I would go ahead and reheat all of the solder joints on that PC board.  You are unlikely to damage anything on there from overheating. 

If you have 12V coming out of the 6.3V pads, you power transformer connections are unlikely to be a problem, but the 1085 regulator isn't doing its job.  This could occur due to soldering issues, an MJE5731A swapped in instead of the 1085, or possibly you have a meter that isn't working properly.  To rule out the meter, you can try measuring a 9V battery with it.

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 22, 2021, 04:36:55 PM

I pulled the power supply off and retested the transformer. I got 9.2
V on the first test and 144v on the second. I also reflowed the joints. I will try soldering the PS board back on and see what happens

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 22, 2021, 04:54:14 PM

Well not sure where to go from here. I’m still getting 13.2v. My meter is good, I reflowed all the joints, they didn’t look bad, but I reflowed them anyway. I also double check the transformer it checks out, so I’m not sure what to do now?

I don’t know enough to know how to trouble shoot.

Can the 1085 be over heated by the solder?  I didn’t really put too much heat on it. I did notice that on each leg on the top side of the board, I used a bit too much solder and each leg had a small ball of solder at the base.  I tried to remove after I tested but really couldn’t get the solder off.

Title: Re: Help. Can’t get past the power supply test.
Post by: Paul Birkeland on February 22, 2021, 07:59:50 PM

Can you post a photo or two looking at the 1085 and what you're seeing?

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 23, 2021, 01:57:33 AM

here you go

Title: Re: Help. Can’t get past the power supply test.
Post by: Deke609 on February 23, 2021, 03:19:38 AM

The right leg of the bottom capacitor could use some more solder.

cheers, Derek

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 23, 2021, 09:25:52 AM

Would that not being fully soldered cause my issue?

Title: Re: Help. Can’t get past the power supply test.
Post by: Paul Birkeland on February 23, 2021, 09:49:38 AM

Yes, if the cap on the output of the regulator isn't well soldered, the regulator may not function properly.

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 23, 2021, 01:21:58 PM

Ok reflowed that one capacitor and triple checked the others, but no change.

At this point I’m not sure what I’m supposed to do.

Title: Re: Help. Can’t get past the power supply test.
Post by: Paul Birkeland on February 23, 2021, 01:24:10 PM

If you'd like, you can mail me the board and I'll get it working for you.  My e-mail is pb(at)bottlehead(dot)com. 

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 23, 2021, 01:39:50 PM

I may have too. Thanks.

Title: Re: Help. Can’t get past the power supply test.
Post by: last lemming on February 23, 2021, 02:08:51 PM

Ok email sent

Title: Re: Help. Can’t get past the power supply test. [mostly resolved]
Post by: last lemming on February 24, 2021, 08:18:36 AM

Paul,

I just think I got your email right, but if you don’t see my email please let me know.

Thanks again for your offer of assistance.

Title: Re: Help. Can’t get past the power supply test. [mostly resolved]
Post by: Paul Birkeland on February 24, 2021, 08:21:35 AM

I received your e-mail and replied with my mailing address.  If you haven't seen that, it's probably in your spam folder.

Title: Re: Help. Can’t get past the power supply test. [mostly resolved]
Post by: last lemming on February 24, 2021, 08:55:52 AM

Ok. I’m not seeing it. I’ll send again.

Thanks.

Title: Re: Help. Can’t get past the power supply test. [mostly resolved]
Post by: Paul Birkeland on February 24, 2021, 10:01:05 AM

I replied again.

Title: Re: Help. Can’t get past the power supply test. [mostly resolved]
Post by: last lemming on February 24, 2021, 10:18:03 AM

Paul,

Im not sure what's going on with getting your email, but I sent you a new one from my office.

Sorry for the inconvenience. 

Greg

Title: Re: Help. Can’t get past the power supply test. [mostly resolved]
Post by: Paul Birkeland on February 24, 2021, 10:24:43 AM

Third reply sent.

Title: Re: Help. Can’t get past the power supply test. [mostly resolved]
Post by: Paul Birkeland on February 27, 2021, 11:24:00 AM

This issue turned out to be a meter issue.