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Hi Guys, I bought a used in very good condition tek 2430 from ebay a week ago for ?51, anyhow it was obvious that it had already been got at once I peeked inside, person before me has replaced a few capacitors in the power supply and also replaced the backup battery which reads 3.7v.

It originally failed on checksum but after a self cal it was working fine, however soon as it warms up 10mins later ch2 fails and I had a 50ohm overload error on screen, I replaced the 3 pin plug on side of Ch2 attenuator and that got rid of the 50ohm overload.

Now I noticed after removing the metal shields on the rear of the attenuators that the 2 wires that come out the back of them, one to the pre-amp, however the one that goes to the variable capacitor Ground isn't actually in that through hole, it is just off to the side touching nothing? I'm going to unsolder and move that ground wire back through the hole.

Somehow I just can't see this fixing the warm up problem, I'm hoping it will and it's not the relays within the attenuator.

I even tried a ext calibration last night but it failed, the trigs calibrated fine though.

A question about the relays inside the attenuator, if I were to buy another ch2 attenuator or even ch1, are these relays identical to each other? as in I could literally swap them around or not.

Thanks Colin

On Wed, Feb 14, 2024 at 12:39 PM, Nathkrul wrote:

I bought a used in very good condition tek 2430 from ebay a week ago for ?51

The CCD's have always been the weak point in 2430's.
There were, if I remember correctly, up to six versions
i.e.last digits in the P/N -00 through -05 where -04 and -05
were the only ones considered reliable. To make things worse
most higher numbers were not a direct replacements for a lower
and required mods of the main board. Tek even had an extended
mandatory replacement of mainboard for some major customers
long after warranty had expired. Repairs in field offices were only
made at board level i.e. board exchange

So if you CCD's are less than -04 that could be the problem.

As it has been pointed out many times on this forum before, do
NOT ever run these scopes out of the case without en external
fan pointed at the main board or it will over heat.

All four relays in the attenuators are the same type and even the
attenuators are identical with only the wire routed to different sides.

/H?kan

Thank you for the reply, I never run it out of the case and used a fan once while checking voltages at test points with fan blowing across the hybrids.

Suppose I'll see tonight when I get home and re-insert that ground wire, if it still fails I'll remove the attenuator and open her up.

Re-attaching the ground wire made zero difference unfortunately, although the test did take longer to fail.

I'm going to attach a signal to both channels and trace it back, hopefully that will give me more insight to the problem area.

On Thu, Feb 15, 2024 at 09:37 AM, Nathkrul wrote:

I'm going to attach a signal to both channels and trace it back

A quick way to determine if one CCD is bad is to swap them between the channels and see if the problem
moves to the other channel. They are easy to remove and come off with four nuts. When reinstalling
push it down gently with one hand to make sure it is properly seated in the holder while attaching the nuts.

/H?kan

Hi,

Check the sockets for the hybrids, they can be faulty. I had problems with
it in a 2440. I cleaned it with IPA and reseated them.

Szabolcs


Nathkrul <nathkrul@...> ezt írta (id?pont: 2024. febr. 15., Cs, 9:37):

And swap them is exactly what I did, I first swapped the outputs from attenuators to see if it was them first and just worked back over till the fault was shown on ch1, and the CCD was the culprit, then came here, and you had suggested exactly what I'd done lol.

It took a bit of cleaning mind, never seen tarnish as bad as this for a while on contacts.

All EXT calibrated and passed all self checks fine, thanks

Thinking of buying a 2465, no trace though, we'll see.