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A.K. Boomer
11-23-2016, 12:38 PM
Ok so my Jenix DRO has been flawless for over a decade now - but now that the temps are cooler it seems to be having trouble firing up when turned on - the screen is all mixed up or nothing at all - I press the on off button a few times and it gets "more involved" till the point where it beeps its normal "on beep" and everything is fine,

im sure this is not going to get better on it's own and will get worse as it seems to be doing,,,

im tempted to tear into it to look the circuit board over for those little "halo" soldered connections at the power entry where heating and cooling cycles can be a factor, have had some pretty good luck with electronics and paying attention to detail. could be a Cap too I suppose???

suggestions??? thanks

A.K. Boomer
11-23-2016, 01:07 PM
up-date, just turned it on for today - same thing - nothing, but instead of playing with the on-off button just let it sit in the on position - after about a half minute the display came on all scrambled - then about another half minute a "beep" and full display...

JoeLee
11-23-2016, 01:20 PM
What is the temperature fluctuation in your shop?? It sounds more like the processor getting tired or a cold solder is another possibility.
Every now and then when I power up my Acu Rite DRP 200M on my BP, the quill scale Z will read 47.xxx It's a 6"scale where does it get 47" from??

JL..............

ikdor
11-23-2016, 01:22 PM
Could be a broken solder joint. When the board warms it makes contact again.
I would open it up and have a close look.

larry_g
11-23-2016, 01:46 PM
It could also be that there is dirt or condensation on the PC board that is allowing some leakage where it does not belong. If you open it up look for how clean things are. You might want to blow it out with some canned air that is safe for electronics. Your regular shop air can create static and kill the electronics.

lg
no neat sig line

macona
11-23-2016, 02:30 PM
Could be a bad solder joint or electrolytic cap.

Leave it on. I have seen more failures from stuff being turned on than stuff left on.

A.K. Boomer
11-23-2016, 03:02 PM
I will have a look into it after im done with this most recent project - but I think that's good advice Macona - I will leave it on until then, they don't consume all kinds of power and I have left it on overnight many a time by accident...

im thinking there's going to be one of those little "halo" fault connections around a resistor wire or something that deals with heating and cooling cycles - I have found tons of these in all different type of electronics,,, outputs on car stereo's are notorious for them.
certain model honda fuel pump relays are another just to name a couple...

thanks guys like to here im on the same track.

Lew Hartswick
11-23-2016, 03:48 PM
Could be a bad solder joint or electrolytic cap.

Leave it on. I have seen more failures from stuff being turned on than stuff left on.
I have had some first hand experience with that in 1953 on a big radar set (CPS6B if anyone ever knew of it) . We ran a fairly long test of not shutting
down for maintenance and the failures were considerably less. It was usually right after turning the set back on after the normal maintenance that the
failures occurred. So there is evidence for letting things powered up, BUT it seems to be a habit (at least for me) to turn things off when I leave them. :-)
...lew...

Hopefuldave
11-23-2016, 04:11 PM
+2 on Lew and Mac's comments, unless it uses glowing valves and Nixie tubes it isn't costing much to leave it on, electrolytics have a habit of going low-value at low temperatures too (old TV repair trick, walk a hairdryer around the board to find the duff cap...), solder joints can crystallize or corrode and it's going to get worse with the "healthy" lead-free solders and their increased creep - there's a reason aviation, military, nuclear and medical are exempt from the lead-free regulations...

Dave H. (the other one)

Black Forest
11-24-2016, 02:45 AM
- but now that the temps are cooler it seems to be having trouble firing up when turned on -

suggestions??? thanks

I am having the same problem A.K. but not with my DRO!:D What is the equivalent of Viagra for a DRO?

oldtiffie
11-24-2016, 05:39 PM
I am having the same problem A.K. but not with my DRO!:D What is the equivalent of Viagra for a DRO?


Testosterone - lots of it and often???

Keep it up or is that the object of the exercise?

Or just creeping "old age?" - senility??.

Tobias-B
11-26-2016, 10:33 PM
Another vote for the electrolytic caps in the power supply.

Either the big ones for DC storage, or a small one in one of the oscillator circuits...

t

A.K. Boomer
12-01-2016, 03:33 PM
Yes I believe it's a Cap ---- I pulled it down today and there's one in the main power board that does not respond to an ohms reading when tested... power board soldered connections look stellar.

it's a 400v 22uF so guess im going to try and find one somewhere

suggestions are appreciated thanks

A.K. Boomer
12-01-2016, 03:39 PM
uh oh maybe I need to learn how to test caps,, when I put the multi meter on volts that one cap is still holding 2.8 volts

suggestions are appreciated lol

sarge41
12-01-2016, 04:22 PM
A.K.: A test meter that reads capacitance as well as the other things. Like duct tape, its a handyman's best friend. I've got an old Fluke 12B that I wouldn't be without, and I'm not an electrician.

Sarge

pinstripe
12-01-2016, 04:28 PM
Get a cheap ESR meter to test the caps. There are videos on YT that show you how to use it. Very easy.

A.K. Boomer
12-01-2016, 07:58 PM
thought I might have had it --- hundreds of soldered connections and then I found the little halo I was talking about - and the other side? a resistor - which makes sense cuz of the heating and cooling cycles,

http://i146.photobucket.com/albums/r249/AK_Boomer/DSC04140_zpsgrm4ljnu.jpg (http://s146.photobucket.com/user/AK_Boomer/media/DSC04140_zpsgrm4ljnu.jpg.html)

http://i146.photobucket.com/albums/r249/AK_Boomer/DSC04138_zps9xzxnj7h.jpg (http://s146.photobucket.com/user/AK_Boomer/media/DSC04138_zps9xzxnj7h.jpg.html)

soldered the connection and still a no-go :-( back to the drawing board... thanks for the advise might have to get a cap checker...

lakeside53
12-01-2016, 09:09 PM
Post a pic of the entire component side circuit boards. If the PSU is separate, toss it and put in an equivalent. I just did this on a Newall - cost - $14. You be amazed how "standard" these can be,

A.K. Boomer
12-01-2016, 09:22 PM
Thanks Lakeside I will pull it down again when I get a chance - was going to take some pics of the two boards - one small power board where the transformers live and a bigger one with all the brains

thought it would be in the power board but sounds like your thinking something different...

jmarkwolf
12-02-2016, 09:21 AM
I've fixed "broken" circuit boards simply by "re-soldering" all the solder joints.

A cold solder joint can sometimes mask the fact that rosin is acting as an insulator between the pin and the solder.

But the suggestions about the electrolytic caps and flaky power supply (first thing I usually check), is valid also.

A.K. Boomer
12-02-2016, 10:18 AM
I've fixed "broken" circuit boards simply by "re-soldering" all the solder joints.

A cold solder joint can sometimes mask the fact that rosin is acting as an insulator between the pin and the solder.

But the suggestions about the electrolytic caps and flaky power supply (first thing I usually check), is valid also.

I try to look at them real close - double magnification, I don't like heating them up unless I have to due to what might be on the other side - I don't have heat sinks or anything, but not afraid of resistors with long wires between them and the board...

Really does seem like it's going to end up being a component like a cap, once it "catches" its good to go for the rest of the day - some kind of bleeddown im thinking like a leaky cap.

A.K. Boomer
01-03-2017, 01:21 AM
Well caps it was, makes sense esp. if your having trouble on fire ups...

after fixing a very expensive TV today I went after the DRO because i made a mental note about two caps I seen in it when snooping around the first time - puffed out on the ends,,,

replaced them and alls good now its instant on just like brand new,

always wondered why I found it hard to throw away old electronics and now I know - had everything here to fix both units...

makes me feel a little better about having a storage room I can't walk through without throwing stuff out of the way to get there,

lakeside here's a pic of the power board I told you I would take when I got the time and motivation to go back in,

puffy caps can be seen at far left,,, I know you would have got this if I took a good enough pic and sent it to you just did not have the need and after learning about the TV I pretty much thought I had a good idea what was wrong with the DRO too.

any of you guys have a problem with your DRO firing up - or not firing up at all - look at the cap ends - good ones should be flat not domed..

http://i146.photobucket.com/albums/r249/AK_Boomer/DSC04222_zpsesoduffh.jpg (http://s146.photobucket.com/user/AK_Boomer/media/DSC04222_zpsesoduffh.jpg.html)

lakeside53
01-03-2017, 11:29 AM
Ha... if you'd sent the picture earlier that's what I (and others) would have told you! ;)

A.K. Boomer
01-03-2017, 11:55 AM
I figured that for sure, it got me through the last project and did not think about it till after fixing the TV.

I remember wondering if they were normal because of that - it's like they have those little cut out lines in the top of them too allow for expansion when something goes wrong, still sealed but I guess a fail safe so they don't turn into a small bomb lol

A.K. Boomer
01-03-2017, 11:57 AM
Lakeside do you see a big issue with me using 85c caps instead of the 105c?

machine is in an always cool basement...

J Tiers
01-03-2017, 02:31 PM
It is very doubtful there would be an issue there.

Possible, not likely.

The 105C parts are generally for cases of high ripple current and parts packed in tightly, as well as high ambient temps. Your unit should not have any of the above.

Yours appears to be a standard low power flyback supply, possibly based on the Power Integrations chip, and should have no issue with it. (I see a DIP IC, and no power transistor, typical of the PI chip supplies)