Tektronix 2221 - Page 1
Forum section: electronics / testgear

author: minerwelder
author_rank: Contributor
timestamp: September 19, 2021, 11:25:46 pm
content: I got a Tek. 2221 scope, tested it it powers on but only gets a dot on crt display it does move around, any suggestions? I have another scope!

author: bdunham7
author_rank: Super Contributor
timestamp: September 19, 2021, 11:27:00 pm
content: Quote from: minerwelder on September 19, 2021, 11:25:46 pmCan you post a photo of the front panel of the scope (whole thing) as it does this?

author: tautech
author_rank: Super Contributor
timestamp: September 19, 2021, 11:29:27 pm
content: Quote from: minerwelder on September 19, 2021, 11:25:46 pmWelcome to the forum.Not in XY mode is it ?

author: David Hess
author_rank: Super Contributor
timestamp: September 20, 2021, 02:18:29 am
content: Not even a readout? Fiddle with the readout intensity control, and then check the power supply voltages according to the manual.

author: minerwelder
author_rank: Contributor
timestamp: September 20, 2021, 01:00:03 pm
content: Tonight I can Thanks

author: minerwelder
author_rank: Contributor
timestamp: September 20, 2021, 01:01:02 pm
content: No ckecked and tryed all modes and settings and intensities.

author: minerwelder
author_rank: Contributor
timestamp: September 20, 2021, 01:01:38 pm
content: I will check those.

author: minerwelder
author_rank: Contributor
timestamp: September 21, 2021, 10:08:37 pm
content: [ Specified attachment is not available ]

author: minerwelder
author_rank: Contributor
timestamp: September 21, 2021, 10:09:55 pm
content: here are photos

author: bdunham7
author_rank: Super Contributor
timestamp: September 21, 2021, 10:28:45 pm
content: OK, that looks a bit rough, but maybe it will work.Start by going to the SEC/DiV knob, push in the small CAL knob on the end and then turn the CAL knob all the way to the right. I can't see where the SEC/DIV indicator is at, so click it all the way clockwise, then ten clicks counterclockwise--that should get us in the ballpark. Flip all of the trigger switches (just above the EXT TRIG connector) all the way up and then find the PP AUTO button above that and push it in. Change the MODE switch to ALT, then rotate the VOLTS/DIV selectors all the way counterclockwise, then select GND on the coupling switches below. Lastly find the INTENSITY knobs (concentric) and turn each of them all the way down (counterclockwise) and then back up again. Do this several times if you don't see anything. Then report back with a new picture.

author: minerwelder
author_rank: Contributor
timestamp: September 23, 2021, 07:36:42 am
content: Ok I'll try this and report back Sunday afternoon! Kevin

author: dl6lr
author_rank: Frequent Contributor
timestamp: September 23, 2021, 08:40:11 am
content: Additional settings (from left to right and from top to bottom):* Put the tip of the CH1 probe to the PROBE ADJUST output* CH1 Vertical position in middle* CH1 VOLTS/DIV full clockwise and 4 clicks ccw (with 10x probe) or 8 clicks ccw (with 1x probe)* CH1 AC coupling* Mode ALT* CH2 Vertical position in middle* CH2 VOLTS/DIV full counterclockwise* CH2 coupling AC* Depress STORE pushbutton to obtain NON-STORE mode* Trigger Holdoff to NORM* Trigger push button P-P AUTO* Trigger INT CH1* Trigger SOURCE INT or LINE if the triggered LED remains darkOr use the user manual page 5-1 for the initial setup (seehttps://w140.com/tekwiki/wiki/2221)

author: minerwelder
author_rank: Contributor
timestamp: September 27, 2021, 01:15:53 am
content: I did the steps you posted and this is the picture, your help is greatly appreciated!

author: bdunham7
author_rank: Super Contributor
timestamp: September 27, 2021, 01:24:31 am
content: Not looking so good.Can you move the dots with the horizontal position knob?Try switching the middle trigger selector to LINE.

author: minerwelder
author_rank: Contributor
timestamp: September 27, 2021, 02:51:48 am
content: I did all of this I get no horizontal trace, I do get channel 1 and 2 dots that I can position I can get vertical line by touching the probes, also in trigger controls the slope button does nothing and the Level and HF reject do nothing, Thanks Kevin

author: bdunham7
author_rank: Super Contributor
timestamp: September 27, 2021, 03:12:26 am
content: Quote from: minerwelder on September 27, 2021, 02:51:48 amYes, you are in for what is probably a moderately complex repair. It looks like a fault in the trigger/sweep area. If the horizontal position knob will move the dots sideways enough, then the horizontal amp is likely OK. So you first need to get a manual and get comfortable with setting it up in the service mode with the storage board folded upwards. Start by testing all the power supplies and doing a close inspection of all the connectors--perhaps you get very lucky and something came undone.

author: David Hess
author_rank: Super Contributor
timestamp: September 27, 2021, 06:02:29 am
content: I thought the 2221 used the same physical arrangement as the 2230 which would make it difficult to service, however the service manual atTekwikiindicates that the 2221 uses the 2232 physical arrangement which is much easier because the storage board can be tilted out of the way without complete disassembly. Page 6-7 describes it.Be sure to start with a physical inspection to see if any connectors inside came loose.

author: minerwelder
author_rank: Contributor
timestamp: September 27, 2021, 11:44:01 am
content: Appreciate the help I'll get to look at it this afternoon!