Author Topic: Tektronix 2465B oscilloscope teardown (Read 721486 times)

MarkL · « **Reply #1650 on:** February 25, 2020, 02:06:38 pm »

Quote from: AMR Labs on February 24, 2020, 10:31:34 pm

If anyone with a plain 2465 or the A version is in need of the original Siemens fan motor, over at the Tekscopes-IO group someone found a seller on ebay that seems to have a big inventory of what seems to be brand new exact replacement motors. As far as I know the B series scopes never used this motor but rather a more common muffin fan type. But I might be wrong on that, and even some early B SN also use this fan. Since this motor is not easy to source, let alone in new condition, and a pain to repair, I thought I pass along this information. Even if yours is still working fine, perhaps a good idea to keep a spare on hand just in case for future needs.

Edit: this fan will also fit the plain 2445 scopes, and as pointed out by the seller, it will also fit some 46x and 47x series as well. Do your own homework, and probably a good idea to check the Tekscopes thread to be sure as I have no experience with those older scopes.

I am in no way connected to the sale.
https://www.ebay.com/itm/274013390896

Here is the original thread at Tekscopes group:
https://groups.io/g/TekScopes/topic/71491839

The price is going up. I bought one for a 2445A a few days ago at $9.99. Yesterday they were $14.99. Now $19.99.

The buying history says someone bought 20 of them, maybe to cash in when they're unobtanium again.

AMR Labs · « **Reply #1651 on:** February 25, 2020, 02:51:02 pm »

Quote from: MarkL on February 25, 2020, 02:06:38 pm

The price is going up. I bought one for a 2445A a few days ago at $9.99. Yesterday they were $14.99. Now $19.99.
The buying history says someone bought 20 of them, maybe to cash in when they're unobtanium again.

Yes indeed saw that too. The person that bough the 20 units might be someone servicing these scopes.
So get your spare motor while there is still a chance.

syau · « **Reply #1652 on:** March 15, 2020, 10:57:30 am »

Just do another 2465B recap, serial number 01xxxx. Fuse blow up after 10 minutes after re-cap, no magic smoke. Turn out that the input bridge rectifier shorted

.

This unit have only 3xxx hrs run time and very clean inside. Only issue (if any) is the beam not prefect circular when I operate in X-Y mode.

factory · « **Reply #1653 on:** March 20, 2020, 08:47:38 pm »

Finally completed the 2465B I started last year, all the radial electrolytic capacitors in the PSU were replaced along with the RIFA stink bombs.
It was then tested before replacing the lithium battery on the A5 board, I soldered on a temporary battery to keep the cal data, I had to write the date of manufacture on the top of the new battery as they decided it was better on the bottom

, all was good after reassembly.

Just got a 2465, 2445 & 2445A left to repair, the 2465 & 2465B both have the TV option (05) fitted, no options fitted to the 2445/A.

David

AMR Labs · « **Reply #1654 on:** March 20, 2020, 09:21:59 pm »

They sold you a 2018 battery in 2020, or did you buy it some time ago?
Even tough we know now these batteries usually will last way past their 10-year life expectancy, academically speaking you basically have only about 80% life left in that one. Still ok but I would have hoped to receive a fresh one that was manufactured not more than 1 year ago or ideally less.

factory · « **Reply #1655 on:** March 20, 2020, 10:13:48 pm »

It was bought from Farnell in October last year, the only trustworthy supplier I could find that would sell this type of battery in the UK.

David

AMR Labs · « **Reply #1656 on:** March 20, 2020, 10:57:49 pm »

Should be ok as long as you did not buy it from a chinese seller on ebay!
Enjoy your scope.

factory · « **Reply #1657 on:** March 26, 2020, 08:05:45 pm »

Had to order another battery from Farnell for the 2445A, I had wrongly assumed it used the older A5 board, it should be here tomorrow.

https://uk.farnell.com/eve/ef651625/battery-lithium-3-6v-prismatic/dp/1973588

David

Gixy · « **Reply #1658 on:** March 27, 2020, 08:15:32 am »

I used this one on my 2445A. It has a bigger capacity (1200 mAh), so will last quite forever...
https://fr.farnell.com/saft/ls14250/batterie-1-2aa-lithium-standard/dp/1282760

syau · « **Reply #1659 on:** March 28, 2020, 01:36:31 am »

I am not able to locate similar battery in Hong Kong and sending one from US through a qualified DG shipment forwarder is extremely expensive therefore I just solder a AA size 3.6V lithium battery

factory · « **Reply #1660 on:** March 29, 2020, 01:41:50 pm »

Can you not find the EVE LTC-7PN battery (made in China) in Hong Kong? I'm guessing the AA or half AA size lithium batteries probably cost less anyway.

David

syau · « **Reply #1661 on:** March 29, 2020, 02:04:50 pm »

Unable to find it in Hong Kong except those Israel made AA lithium battery

factory · « **Reply #1662 on:** March 29, 2020, 08:49:47 pm »

Funny you should mention that, I used one of those Israel made half AA batteries as a temporary supply during replacement.

David

med6753 · « **Reply #1663 on:** March 29, 2020, 11:40:37 pm »

The reason the LTC-7P battery may be difficult to source is that lithium batteries cannot go air freight. So if your country has no local stock it may be difficult, if not impossible, to procure. The Tek 2430 DSO uses the same battery for NVRAM. I recently replaced the battery in mine and I purchased it from Mouser but it had to ship UPS ground. And when I received the package it had a label on it stating that it contained hazardous material that could not go air freight.

Here's the change out procedure for the 2430. It's more complex than the 2465 as the board containing the battery is not readily accessible like the A5 board. I used an HP 6215A power supply set to 3.6V as backup while changing the battery.

emece67 · « **Reply #1664 on:** March 30, 2020, 01:16:46 pm »

syau · « **Reply #1665 on:** March 31, 2020, 03:52:13 pm »

Quote from: syau on March 29, 2020, 02:04:50 pm

Unable to find it in Hong Kong except those Israel made AA lithium battery

Found RS did sell cheaper than I get from local retail shop who sell various battery. RS said it will take them around 44 days to ship on ship from UK

rigmo · « **Reply #1666 on:** August 15, 2020, 11:46:58 am »

HI, can you help me to fix my new oscilloscope
flickering https://youtu.be/s0we1dCMUXw

I got a gift 2465B from my dear friend in Germany who died from cancer a few months ago...
I have a problem with an oscilloscope and for legacy and memory on him I won't repair.. can you help

Thank You in Advance
Best Regards

Satbeginner · « **Reply #1667 on:** August 15, 2020, 12:49:32 pm »

Looks perfectly ok to me

BravoV · « **Reply #1668 on:** August 15, 2020, 02:51:35 pm »

If you are complaining that all LEDs are blinking "faintly altogether" whenever button is pressed, yes, that is normal for 2565B, no worry.

rigmo · « **Reply #1669 on:** August 15, 2020, 06:35:06 pm »

I believe problems bad caps... thank you..
one more question.. my curiosity is hoe to see power on hours and cycle counts on machine... how to know?
Today i find crazy link https://hackaday.io/project/163890-tektronix-2465-series-servicing#j-discussions-title

Gregory · « **Reply #1670 on:** August 15, 2020, 11:45:13 pm »

Hi guys!

I bought a 2465A with a bad channel 1 input module. The problem was a burned resistor in the 50ohm input path.

I soldered two thru hole resistors and the unit got back to normal operation! I got very impressed because with a fast pulse generator I'm not seeing any difference between this channel and the original channel 2. Pretty interesting !

AMR Labs · « **Reply #1671 on:** August 15, 2020, 11:54:15 pm »

Not very familiar with the input board, but just wondering what was the value of the original resistor that burned up? Two 68-ohm in parallel as you seem to have used will give you about 34 ohms.

Gregory · « **Reply #1672 on:** August 16, 2020, 12:09:34 am »

Yep, It was very close to 34 ohms.. It makes a input attenuator with other Rs.
I was afraid to open the input module but it was my only option!

In this picture you can see the burned resistor complete split in half

mawyatt · « **Reply #1673 on:** August 16, 2020, 01:36:57 pm »

Quote from: Gregory on August 15, 2020, 11:45:13 pm

Hi guys!

I bought a 2465A with a bad channel 1 input module. The problem was a burned resistor in the 50ohm input path.

I soldered two thru hole resistors and the unit got back to normal operation! I got very impressed because with a fast pulse generator I'm not seeing any difference between this channel and the original channel 2. Pretty interesting !

I'm surprised that the extra inductance of the leaded resistors didn't effect the BW or pulse response. Might want to consider a large chip resistor (lower inductance) instead of the leaded resistors.

I had a bad channel 1 (very erratic) and 2 had some issues also on a ebay purchased 2465. This was traced to the input hybrid modules and the relay contacts. I carefully cleaned the relay contacts and hybrid contact areas with a lightly abrasive pencil eraser, then cleaned with alcohol. This fixed the problem, I suspect that film had deposited on the contacts, maybe from cigarette smoke, which interfered with the contacts. While you have these hybrids open you might want to consider cleaning the relay contacts and contact area.

Anyway, nice work

Best,

AMR Labs · « **Reply #1674 on:** August 16, 2020, 05:01:20 pm »

Since it is not mentioned, the question would of course be what was the highest frequency (or fastest pulse width) used as comparison between ch1 and ch2 performance. I bet it was not anywhere near to about 100MHz where you would expect the leads of the resistors to start playing a part by adding inductance.


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Author Topic: Tektronix 2465B oscilloscope teardown (Read 721486 times)

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