Bottlehead Forum

Bottlehead Kits => Moreplay => Moreplay Upgrade => Topic started by: Colman on July 14, 2025, 02:36:37 PM

Title: Check the power supply voltage by measuring DC voltage between the chassis plate
Post by: Colman on July 14, 2025, 02:36:37 PM

Hello, I am on page 25 of the Moreplay Upgrade manual. I am confused by the instruction "Check the power supply voltage by measuring DC voltage between the chassis plate and terminal 21." One of my test meter leads goes to terminal 21. Where do I clip the other?

Title: Re: Check the power supply voltage by measuring DC voltage between the chassis plate
Post by: Paul Birkeland on July 14, 2025, 02:50:50 PM

Any metal on or touching the chassis plate. Any of the RCA jack ground tabs, any of the center lugs of any of the terminal strips, the IEC power entry module earth lug, stuff like that.

Title: Re: Check the power supply voltage by measuring DC voltage between the chassis plate
Post by: AG on July 14, 2025, 05:06:54 PM

Quote from: Colman on Yesterday at 02:36:37 PM

Hello, I am on page 25 of the Moreplay Upgrade manual. I am confused by the instruction "Check the power supply voltage by measuring DC voltage between the chassis plate and terminal 21." One of my test meter leads goes to terminal 21. Where do I clip the other?

This is to be sure the filters are not charged.
If you can discharge the filters safely you will save 15 min or so.
Andre.

Title: Re: Check the power supply voltage by measuring DC voltage between the chassis plate
Post by: Colman on July 15, 2025, 08:43:52 AM

OK, I get it. If I wait 10 minutes, is that enough time for "the high voltage power supply will need several minutes to drain before you can move the clip leads"

Title: Re: Check the power supply voltage by measuring DC voltage between the chassis plate
Post by: AG on July 15, 2025, 09:36:14 AM

Don't assume regarding time is to risky.
better measure it and be sure is less than 20V.

Andre.

Title: Re: Check the power supply voltage by measuring DC voltage between the chassis plate
Post by: Colman on July 15, 2025, 10:10:57 AM

I will measure then. Thanks for your help!

Title: Re: Check the power supply voltage by measuring DC voltage between the chassis plate
Post by: Colman on July 15, 2025, 11:48:21 AM

Uh oh! I checked the B socket and it measured an acceptable 6.25 V. After 10 minutes, I went to check the chassis. I unplugged the red probe from B2. I forgot I still had the black probe clipped on B7. As soon as I touched the red probe to terminal 21, there was a big spark at terminal 21! I'm unharmed but it really woke me up! Do you think I damaged the Moreplay?