Bottlehead Forum

Bottlehead Kits => Eros Phono => Topic started by: CrowDaddy on November 30, 2020, 12:57:11 PM

Title: CCS board problems [resolved]
Post by: CrowDaddy on November 30, 2020, 12:57:11 PM

My Eros2 worked fine for several weeks, then suddenly the left channel started dropping out with a loud 'pop'; would occur with even a light tap on tubes or baseplate.  Would occasionally come back in, only to disappear.

Well, I did voltage checks and found a problem on the CCS board:
IB 214.2, OB 112 falling to 57, AD 100 falling to 57, OKB 100 falling to 64, OKD 1.9 rising to 2.1. Right channel values were all within spec.

So, I partly dismounted the CCS board, reflowed almost everything on the left channel, and lo! found a tiny piece of component lead propped between two lugs of the 6922 socket.  Remounted the CCS board, but now there are different problems:

IA 214.7, IB 214.7, OB 160.1, ( OA 160.4), OC 156.3, OD 155.8, OKA 155.5, OKB 155.0, OKC 13.07, OKD 13.04

I studied the bottom of the CCS board after reflowing, so am pretty sure there are no bridges.  What would you suggest?  Are there measurements I can take from the top of the CCS board which would help?

Thanks in advance for your time.

Title: Re: CCS board problems
Post by: Paul Birkeland on November 30, 2020, 01:36:20 PM

I would suggest triple checking that you put the wires back in the correct holes.

Title: Re: CCS board problems
Post by: CrowDaddy on December 01, 2020, 12:22:34 PM

Well Paul, your guess was close:  I had attached ( but not soldered) the CCS board ground wire to U11, and it came loose while I was manipulating the CCS board.  Now all voltages are within spec and the unit sounds good again. 
Amazed that the CCS board tolerated those out-of-voltage conditions; do you guys design the kits so they are robust to abuse?
Thanks again !

Title: Re: CCS board problems
Post by: Paul Birkeland on December 01, 2020, 12:48:25 PM

Any robustness is purely accidental!