Author Topic: Solartron 7150 check and a small repair  (Read 7359 times)

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Offline Jwalling

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Re: Solartron 7150 check and a small repair
« Reply #25 on: August 20, 2016, 09:43:22 pm »
I can't believe I didn't notice this |O, you guys are absolutely correct, I am sorry for dragging you in a wild goose chase  :(, I will be editing the first post to reflect this finding and thanks again.

Did you apply power to it with it in backwards? If so, replace it to be safe.

Jay
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Offline h.bashar

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Re: Solartron 7150 check and a small repair
« Reply #26 on: August 20, 2016, 09:58:31 pm »
Unfortunately I did :(, definitely it will get a proper replacement thanks Jay.
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius, and a lot of courage to move in the opposite direction".
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Offline Prehistoricman

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Re: Solartron 7150 check and a small repair
« Reply #27 on: August 20, 2016, 11:53:22 pm »
So... how come the problem appeared fixed when you placed the cap in the wrong polarity?
 

Offline Jwalling

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Re: Solartron 7150 check and a small repair
« Reply #28 on: August 21, 2016, 12:55:16 am »
So... how come the problem appeared fixed when you placed the cap in the wrong polarity?

Possibly just opening it up and messing around inside for a bit. Could indicate a bad connector/solder joint... :-//

Jay
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Offline h.bashar

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Re: Solartron 7150 check and a small repair
« Reply #29 on: August 21, 2016, 07:50:04 am »
All polarized CAPS have now been removed waiting new replacements, first post updated to reflect new findings.
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius, and a lot of courage to move in the opposite direction".
- Albert Einstein
 

Offline h.bashar

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Re: Solartron 7150 check and a small repair
« Reply #30 on: August 21, 2016, 07:53:46 am »
So... how come the problem appeared fixed when you placed the cap in the wrong polarity?
In addition to what Jay said I have no idea but further checking revealed more broken CAPS and that magical CAP is still functional |O
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius, and a lot of courage to move in the opposite direction".
- Albert Einstein
 

Offline Jwalling

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Re: Solartron 7150 check and a small repair
« Reply #31 on: August 21, 2016, 08:01:28 am »
So... how come the problem appeared fixed when you placed the cap in the wrong polarity?
In addition to what Jay said I have no idea but further checking revealed more broken CAPS and that magical CAP is still functional |O

Broken/bad or mis-labeled polarity?
Jay

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Offline h.bashar

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Re: Solartron 7150 check and a small repair
« Reply #32 on: August 21, 2016, 08:58:50 am »
So... how come the problem appeared fixed when you placed the cap in the wrong polarity?
In addition to what Jay said I have no idea but further checking revealed more broken CAPS and that magical CAP is still functional |O

Broken/bad or mis-labeled polarity?

so far just  one mislabelled on the capacitor body itself, two broken and one near bad. just a word of caution: some of these CAPS have some sort of enamel cover around their leads so care is needed to where LCR probes placed specially when they are still on board.
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius, and a lot of courage to move in the opposite direction".
- Albert Einstein
 

Offline guido

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Re: Solartron 7150 check and a small repair
« Reply #33 on: August 22, 2016, 06:41:55 am »
The smaller silver caps look to me like they are wet tantalum caps. If so they should be very good caps.
So i'm wondering if the faulty caps you found were regular caps or tants.
 

Offline cncjerry

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Re: Solartron 7150 check and a small repair
« Reply #34 on: August 22, 2016, 07:03:28 am »
a lot of people needlessly wholesale replace caps in old equipment. I have yet to find one of those small silver electrolytic caps to be bad and I have about 40 pieces of old gear, maybe more.

Can you plot the negative trace and post it up here? Are there relays in the circuit?  A poor relay contact could cause your problem as well.
 

Offline h.bashar

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Re: Solartron 7150 check and a small repair
« Reply #35 on: August 22, 2016, 07:08:46 am »
The smaller silver caps look to me like they are wet tantalum caps. If so they should be very good caps.
So i'm wondering if the faulty caps you found were regular caps or tants.
The faulty ones are regular caps. the smaller silver caps are fine (STC TAA hermetically sealed solid tantalum cap).
« Last Edit: August 22, 2016, 07:42:50 am by h.bashar »
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius, and a lot of courage to move in the opposite direction".
- Albert Einstein
 

Offline h.bashar

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Re: Solartron 7150 check and a small repair
« Reply #36 on: August 22, 2016, 07:16:10 am »
a lot of people needlessly wholesale replace caps in old equipment. I have yet to find one of those small silver electrolytic caps to be bad and I have about 40 pieces of old gear, maybe more.

Can you plot the negative trace and post it up here? Are there relays in the circuit?  A poor relay contact could cause your problem as well.

I agree, not to mention expensive! compared to what was paid for the old unit itself, however with units like a bench multimeter switched on for long times its probably best to replace the electrolytic caps at least. as for the negative trace, until the caps get replaced I cant check it again, it could be as you mentioned a bad relay contact  (highly probable considering the age of the device).
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius, and a lot of courage to move in the opposite direction".
- Albert Einstein
 

Offline kutte

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Re: Solartron 7150 check and a small repair
« Reply #37 on: August 23, 2016, 03:30:06 am »

I agree, not to mention expensive! compared to what was paid for the old unit itself, however with units like a bench multimeter switched on for long times its probably best to replace the electrolytic caps at least. as for the negative trace, until the caps get replaced I cant check it again, it could be as you mentioned a bad relay contact  (highly probable considering the age of the device).

...and do not forget to replace the mains-power filter. They tend to explode with nasty consequences.
Kutte
 

Offline h.bashar

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Re: Solartron 7150 check and a small repair
« Reply #38 on: August 23, 2016, 05:05:23 am »
Ordered the filter from RS today  :)
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius, and a lot of courage to move in the opposite direction".
- Albert Einstein
 

Offline h.bashar

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Re: Solartron 7150 check and a small repair
« Reply #39 on: August 26, 2016, 09:10:04 am »
Did some resistance checks using 110, 1K, 10K, 100K all 0.1%, 1M and 10M 1%, mostly everything is within tolerance  :-+ (except for the 10M resistor), will get REF102 to test DC voltage range.
« Last Edit: August 26, 2016, 09:13:25 am by h.bashar »
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius, and a lot of courage to move in the opposite direction".
- Albert Einstein
 


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