Telequipment D65 scope faulty - UK Vintage Radio Repair and Restoration Discussion Forum

FIXITNOW · 17th Jun 2013, 7:58 am

Telequipment D65 scope
Got this of my local freecycle group it’s in need of repair
Never repaired a scope so need some guidance and a scan of the service manual please

The fault is on the screen I only have an unfocused 1 cm wide vertical line that runs from top to bottom I can move it left to right with the position pot but that’s all
Cheers
Vince

FIXITNOW · 17th Jun 2013, 8:30 am

have managed to get the D65/D66 service manual a scan of fair qualty
just need a pointer in the right direction

mark pirate · 17th Jun 2013, 8:35 am

Hi Vince, I have a pdf copy of the manual, if you would like it please PM me your email address.

Mark

maninashed · 17th Jun 2013, 11:21 am

Sounds like the timebase is not running. First job on any instrument such as this is to check all the power supply rails against the manual and get that right first. If you don't check all the psu outputs for correct voltage and ripple, you will be chasing your tail. Be careful when dealing with the eht section.
Bill

FIXITNOW · 17th Jun 2013, 11:34 am

cheers will start there
and report back

MotorBikeLes · 17th Jun 2013, 11:24 pm

I don't remember exactly, but I think the mains incoming is exposed at the fuse. Possibly a bigger danger than the EHT? I usually put some sort of plastic insulator over the fuseholder. TQ also did a mod whereby a plastic lid was retrofitted over the voltage selector plug/socket. If you are idiot enough, you could poke a bit of wire, or even a wet pencil lead in there and get a tickle, hence that mod.
Les.

FIXITNOW · 18th Jun 2013, 7:23 am

Tthanks Lles good tip.
Wwill look at doing the same.

FIXITNOW · 19th Jun 2013, 8:01 am

OKok got back to this it has already had a new mains lead fitted and the fuse holder insulated.
Aall power rails measure OKok and there is very little ripple on them.

I did notice when Ii power off the display becomes a dot that falls from the top of the display to the centre and fades away. The dot size changes depending on how the focus control is set.

maninashed · 19th Jun 2013, 8:29 am

That sounds like the Y amp is unbalanced. Basically its a wideband amplifier with a push-pull output operating on the Y plates of the crt. You need to check the output voltages on the output to the plates, you will probably find that you have a severe imbalance. If so check the output transistors. Voltages in this area must be as per the manual.Check also that all transistors are present and if socketed, give them a twiddle to ensure good contact.
Also, if the spot doesn't move when the timebase control is advanced, then there is a fault in the timebase too.
Bill

FIXITNOW · 19th Jun 2013, 9:31 am

will have a look cheers

17th Jun 2013, 7:58 am	#1
FIXITNOW Octode Join Date: Feb 2007 Location: Ely, Cambridgeshire, UK. Posts: 1,976	Telequipment D65 scope faulty Telequipment D65 scope Got this of my local freecycle group it’s in need of repair Never repaired a scope so need some guidance and a scan of the service manual please The fault is on the screen I only have an unfocused 1 cm wide vertical line that runs from top to bottom I can move it left to right with the position pot but that’s all Cheers Vince

17th Jun 2013, 8:30 am	#2
FIXITNOW Octode Join Date: Feb 2007 Location: Ely, Cambridgeshire, UK. Posts: 1,976	Re: Telequipment D65 scope faulty have managed to get the D65/D66 service manual a scan of fair qualty just need a pointer in the right direction

17th Jun 2013, 8:35 am	#3
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: Telequipment D65 scope faulty Hi Vince, I have a pdf copy of the manual, if you would like it please PM me your email address. Mark

17th Jun 2013, 11:21 am	#4
maninashed Rest in Peace Join Date: May 2011 Location: Preston, Lancashire UK Posts: 955	Re: Telequipment D65 scope faulty Sounds like the timebase is not running. First job on any instrument such as this is to check all the power supply rails against the manual and get that right first. If you don't check all the psu outputs for correct voltage and ripple, you will be chasing your tail. Be careful when dealing with the eht section. Bill

17th Jun 2013, 11:34 am	#5
FIXITNOW Octode Join Date: Feb 2007 Location: Ely, Cambridgeshire, UK. Posts: 1,976	Re: Telequipment D65 scope faulty cheers will start there and report back

17th Jun 2013, 11:24 pm	#6
MotorBikeLes Nonode Join Date: Dec 2012 Location: Kirk Michael, Isle of Man Posts: 2,350	Re: Telequipment D65 scope faulty I don't remember exactly, but I think the mains incoming is exposed at the fuse. Possibly a bigger danger than the EHT? I usually put some sort of plastic insulator over the fuseholder. TQ also did a mod whereby a plastic lid was retrofitted over the voltage selector plug/socket. If you are idiot enough, you could poke a bit of wire, or even a wet pencil lead in there and get a tickle, hence that mod. Les.

18th Jun 2013, 7:23 am	#7
FIXITNOW Octode Join Date: Feb 2007 Location: Ely, Cambridgeshire, UK. Posts: 1,976	Re: Telequipment D65 scope faulty Tthanks Lles good tip. Wwill look at doing the same.

19th Jun 2013, 8:01 am	#8
FIXITNOW Octode Join Date: Feb 2007 Location: Ely, Cambridgeshire, UK. Posts: 1,976	Re: Telequipment D65 scope faulty OKok got back to this it has already had a new mains lead fitted and the fuse holder insulated. Aall power rails measure OKok and there is very little ripple on them. I did notice when Ii power off the display becomes a dot that falls from the top of the display to the centre and fades away. The dot size changes depending on how the focus control is set.

19th Jun 2013, 8:29 am	#9
maninashed Rest in Peace Join Date: May 2011 Location: Preston, Lancashire UK Posts: 955	Re: Telequipment D65 scope faulty That sounds like the Y amp is unbalanced. Basically its a wideband amplifier with a push-pull output operating on the Y plates of the crt. You need to check the output voltages on the output to the plates, you will probably find that you have a severe imbalance. If so check the output transistors. Voltages in this area must be as per the manual.Check also that all transistors are present and if socketed, give them a twiddle to ensure good contact. Also, if the spot doesn't move when the timebase control is advanced, then there is a fault in the timebase too. Bill

19th Jun 2013, 9:31 am	#10
FIXITNOW Octode Join Date: Feb 2007 Location: Ely, Cambridgeshire, UK. Posts: 1,976	Re: Telequipment D65 scope faulty will have a look cheers