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Tektronix 2215 Oscilloscope

Adam H
 

I was recently given the above which had been in storage for many years. I left it in my living room for a few days in case it was suffering form dampness. When I switched it on at first I got both traces on screen. Within a few minutes it tripped my (RCD) mains supply. Each time I tried to switch it on, the same thing happened. I disconnected the earth and tried again, it powered up but the screen trace was very distorted (without any input).
I have never repaired an oscilloscope before but I was thinking I should replace electrolytic caps in the power supply first and take it from there. I would appreciate any advise from anyone with some product knowledge.
I managed to get hold of a pdf service manual.
Adam

Jim H.
 

As an American, I had to search "RCD", which seems to be the same as our ground fault interrupter (GFI).  Obviously, there is a leakage path which must be addressed as it's a safety hazard.  It's possible the leakage path is caused by dirt and moisture on the chassis.  You say you've never repaired an oscilloscope, but are you familiar with repairing other mains-powered equipment?

There may be some relevant information here:  https://www.eevblog.com/forum/repair/tektronix-2215-problem/


On 8/27/2018 10:59 AM, Adam H wrote:
I was recently given the above which had been in storage for many years. I left it in my living room for a few days in case it was suffering form dampness. When I switched it on at first I got both traces on screen. Within a few minutes it tripped my (RCD) mains supply. Each time I tried to switch it on, the same thing happened. I disconnected the earth and tried again, it powered up but the screen trace was very distorted (without any input).
I have never repaired an oscilloscope before but I was thinking I should replace electrolytic caps in the power supply first and take it from there. I would appreciate any advise from anyone with some product knowledge.
I managed to get hold of a pdf service manual.
Adam

Adam H
 

Hi Jim,

Adam H
 

Didn't know you called RCDs a different thing over there. A true saying “we are separated by a common language”.

 

Yes, I have worked on many types of mains powered equipment in the past, but never on an oscilloscope. I know this scope has a switched mode power supply and they can be very dangerous. I will be very careful, thanks for your concern.

 

I have blown out most of the dust, to be honest, there was not much considering its age. I don't think it has a damp problem. It was well wrapped up when it was in storage and it has been in my (warm) house now for a couple of weeks. When I switched it on today it ran for about half an hour before it tripped the supply. During that time I got two traces but they were stuck on the lower part of the screen, with the vert position control fully upwards. I don't know if that is a clue as to where the fault lies ??

 

There is a lot of information on the link you sent me. I will work my way through it. Thank You.

 

Adam.
PS. I Live in Scotland

 

If it’s blowing the RCD, then it’s very likely to be the class X/class Y caps on the power supply board, or maybe in the IEC mains inlet.

 

Though do check the mains cable – I had a rubber insulated one of those where the internal insulation had just crumbled and was shorting intermittently.

 

HtH

Dave

 

From: TekScopes2@groups.io [mailto:TekScopes2@groups.io] On Behalf Of Adam H
Sent: 29 August 2018 00:03
To: TekScopes2@groups.io
Subject: Re: [TekScopes2] Tektronix 2215 Oscilloscope

 

Didn't know you called RCDs a different thing over there. A true saying “we are separated by a common language”.

 

Yes, I have worked on many types of mains powered equipment in the past, but never on an oscilloscope. I know this scope has a switched mode power supply and they can be very dangerous. I will be very careful, thanks for your concern.

 

I have blown out most of the dust, to be honest, there was not much considering its age. I don't think it has a damp problem. It was well wrapped up when it was in storage and it has been in my (warm) house now for a couple of weeks. When I switched it on today it ran for about half an hour before it tripped the supply. During that time I got two traces but they were stuck on the lower part of the screen, with the vert position control fully upwards. I don't know if that is a clue as to where the fault lies ??

 

There is a lot of information on the link you sent me. I will work my way through it. Thank You.

 

Adam.
PS. I Live in Scotland

Chris Smith <me@...>
 

I'd agree. There's a mains filter board on the 2215. I think that can be unplugged from the main board. I'd pull it off and see if it still blows the RCD after a bit. That should isolate it to the power supply or the filter. Divide and conquer!

If it's like the 2225, which was stuffed full of those horrible incendiary RIFA gold capacitors, I'd almost certainly just replace them anyway. Had a couple of those go off on me.

If the traces are stuck on one half of the screen, check that the deflection plates are still connected to the board. They seem to fall off periodically and cause limited deflection on some scopes.

Best regards,

Chris


On Wed, 29 Aug 2018, at 10:21, David C. Partridge wrote:

If it’s blowing the RCD, then it’s very likely to be the class X/class Y caps on the power supply board, or maybe in the IEC mains inlet.

 

Though do check the mains cable – I had a rubber insulated one of those where the internal insulation had just crumbled and was shorting intermittently.

 

HtH

Dave

 

From: TekScopes2@groups.io [mailto:TekScopes2@groups.io] On Behalf Of Adam H
Sent: 29 August 2018 00:03
To: TekScopes2@groups.io
Subject: Re: [TekScopes2] Tektronix 2215 Oscilloscope

 

Didn't know you called RCDs a different thing over there. A true saying “we are separated by a common language”.

 

Yes, I have worked on many types of mains powered equipment in the past, but never on an oscilloscope. I know this scope has a switched mode power supply and they can be very dangerous. I will be very careful, thanks for your concern.

 

I have blown out most of the dust, to be honest, there was not much considering its age. I don't think it has a damp problem. It was well wrapped up when it was in storage and it has been in my (warm) house now for a couple of weeks. When I switched it on today it ran for about half an hour before it tripped the supply. During that time I got two traces but they were stuck on the lower part of the screen, with the vert position control fully upwards. I don't know if that is a clue as to where the fault lies ??

 

There is a lot of information on the link you sent me. I will work my way through it. Thank You.

 

Adam.
PS. I Live in Scotland





Adam H
 

Yes, I have already tried a different mains lead.

Got the main cover removed from the power supply but couldn't get to the board below as my Torx Keys don't go down that far. Have ordered some smaller ones.

I can see a couple of newish caps in the power supply, maybe a recurring problem??. Will get back to you soon.

Thanks for your help so far

Adam