19th Jan 2014, 7:19 pm | #161 |
Retired Dormant Member
Join Date: Aug 2013
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 330
|
Re: Pye Black Box
Main lead connectors measure 227v on/off switch measures 227v and the player voltage selector is still in the correct place.
Kevin |
19th Jan 2014, 7:54 pm | #162 | |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Pye Black Box
Looks like the laws of physics don't apply in Newcastle upon Tyne. 117 volts disappearing in a bit of wire?
Quote:
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
|
20th Jan 2014, 12:23 am | #163 |
Retired Dormant Member
Join Date: Aug 2013
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 330
|
Re: Pye Black Box
The voltage at the PRIMARY is 110v.
|
20th Jan 2014, 10:00 am | #164 |
Retired Dormant Member
Join Date: May 2013
Location: Finchley, London, UK.
Posts: 81
|
Re: Pye Black Box
The only thing between the primary and the mains cable is the power switch. Seems odd, but wonder if that could be causing it? Could you try bypassing the switch maybe?
|
20th Jan 2014, 10:01 am | #165 |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
|
Re: Pye Black Box
Seconded. The Pye BB is a darn good machine.
__________________
Mike. |
21st Jan 2014, 1:43 pm | #166 |
Retired Dormant Member
Join Date: May 2013
Location: Finchley, London, UK.
Posts: 81
|
Re: Pye Black Box
Thirded. If it's really doing your head in, maybe look out for another amplifier - they do come up on eBay sites frequently enough. No point junking the cabinet, deck or speakers. You could then either keep the old amp for spares, or sell it as not working.
|
21st Jan 2014, 11:45 pm | #167 |
Rest in Peace
Join Date: Feb 2004
Location: Hexham, Northumberland, UK.
Posts: 2,234
|
Re: Pye Black Box
Kevin, if you're really at your wit's end with it, I could have a look at the amp for you. Have you a circuit diagram for it? If so send me a PM and I'll see what I can do. I would hate to see you give up on this one!
Alan. |
22nd Jan 2014, 5:05 pm | #168 |
Retired Dormant Member
Join Date: Aug 2013
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 330
|
Re: Pye Black Box
Here are two pictures to illustrate the problem I seem to be having. First photo is the voltage at the on/off switch - 234Vac, second photo 113Vac at the transformer primaries. Any help identifying whether I'm doing something wrong or if the transformer's goosed, or the On/Off switch is broken would be much appreciated.
Thanks Kevin |
22nd Jan 2014, 5:34 pm | #169 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Pye Black Box
You need to check the voltage at both the input and output of the OFF/ON switch. If the reading at the output is 117V, then the switch is faulty.
If the reading at the output is 234V the switch is OK and it's possible the voltage selector isn't making good contact. You talk of transformer PRIMARIES ie plural. If there are two primary windings which can be wired in series or parallel, they'll be wired in series for the UK mains voltage and you will see 117V across each winding. Is it just coincidence that 117V is exactly half 234V?
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
22nd Jan 2014, 5:53 pm | #170 |
Retired Dormant Member
Join Date: Aug 2013
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 330
|
Re: Pye Black Box
A better description would be the primary tags. The voltage at the input and output of the switch is 234v. I have cleaned and made sure the voltage selector is making good contact and still the same results.
Kevin |
22nd Jan 2014, 5:58 pm | #171 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Pye Black Box
So there is only one primary winding?
You need to find out where the volt drop is occurring. Clip one meter lead to the neutral side of the mains cable where it is first terminated inside the player. Probably on the OFF/ON switch. Meter set to AC volts, switch on the player. Use the other lead to probe each point in the primary circuit. You should only see a volt drop across the primary winding. In your case you're ging to see a 117V drop elsewhere. That'll be where the fault is.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
22nd Jan 2014, 8:27 pm | #172 |
Octode
Join Date: Jul 2006
Location: Willand, Devon, UK.
Posts: 1,023
|
Re: Pye Black Box
The 0V end and the 3 tap wires can be seen in the photos of the transformer, are you testing from the correct point? I can't see how else you are getting 117V at the primary. If it was open circuit you would get 240V, if it had shorted turns I would expect would get smoking/ overheating/ blown fuses.
Are the heaters lit? see here: Last edited by Station X; 22nd Jan 2014 at 10:29 pm. Reason: Image rotated. |
22nd Jan 2014, 8:45 pm | #173 |
Heptode
Join Date: Dec 2010
Location: Barnstaple, N.Devon, UK.
Posts: 557
|
Re: Pye Black Box
Hi, Kevin. Are you sure you are probing the right terminal on the transformer? I wouldn't expect the 240v tap to be next to the 0v tap. Try probing the next 2 taps with one probe whilst leaving the other connected to the white wire tap.
I could be completely wrong though but it's just my observation. David. |
22nd Jan 2014, 9:35 pm | #174 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,865
|
Re: Pye Black Box
Kevin, with the unit unplugged, the deck motor unplugged, and the power switch in the on position, and the voltage selector on its highest range, connect a resistance meter to the L & N terminals of the mains plug.
What reading do you get? According to the manual, it should be roughly 38 ohms. Nick. |
22nd Jan 2014, 10:21 pm | #175 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,536
|
Re: Pye Black Box
According to that circuit snippet, there's a 110V tap on the TX primary. If you measure the voltage between that tap and neutral (or live) end of the primary, you'll get that 117V!
__________________
....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
22nd Jan 2014, 10:46 pm | #176 |
Retired Dormant Member
Join Date: Aug 2013
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 330
|
Re: Pye Black Box
David - reading from the bottom tag (white) up
Tag 2 = 115Vac Tag 3 = 212Vac Tag 4 = 238Vac Tag 5 = 5Vac Tag 6 = Ov Nick - I measure 39Ω's at the plug terminals Thanks Kevin |
22nd Jan 2014, 10:49 pm | #177 | |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Pye Black Box
Looks like we're back at post #159 then.
Quote:
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
|
22nd Jan 2014, 10:56 pm | #178 | |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,865
|
Re: Pye Black Box
Quote:
Is the pilot light lit? N. |
|
22nd Jan 2014, 11:06 pm | #179 |
Retired Dormant Member
Join Date: Aug 2013
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 330
|
Re: Pye Black Box
Pilot light is lit
|
22nd Jan 2014, 11:12 pm | #180 |
Moderator
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,225
|
Re: Pye Black Box
If the pilot light is lit, then the transformer is getting power and working.
You should see the valves lighting up. You shuld also be able to measure HT approx 280V across the reservoir capacitor. Did you replace the bridge rectifier? |