HP 1650A Logic Analyzer
Hi Folks! Continuing to put back to life my old test equipment... I stored my HP 1650A Logic Analyzer in working order about 6 years ago. I bought it used - I think it was highly used once the screen has signs of burn on it. Yesterday, when I finished to fix my Fluke 9010A, I've decided to try the 1650A and nope... The power source clicks and the voltages are not correct. 7V instead of 12V, 4,5V instead of 5V and oscillating. I have not experience in PS repair, but someone told me that the electrolytic capacitors may be dry due the time it was stored (as well as de condition, one it was in Rio de Janeiro, and at summer time, the room temperature may be more them 120F) Could someone confirm that please ? Thank you very much ! JL _______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com http://seven.pairlist.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
Yes all electrolytics are suspect especially the output filter caps. Kevin On Mar 5, 2013 1:35 PM, "Jose Luiz Martins" <joseluizmartins@gmail.com> wrote:
Hi Folks!
Continuing to put back to life my old test equipment...
I stored my HP 1650A Logic Analyzer in working order about 6 years ago. I bought it used - I think it was highly used once the screen has signs of burn on it.
Yesterday, when I finished to fix my Fluke 9010A, I've decided to try the 1650A and nope...
The power source clicks and the voltages are not correct. 7V instead of 12V, 4,5V instead of 5V and oscillating.
I have not experience in PS repair, but someone told me that the electrolytic capacitors may be dry due the time it was stored (as well as de condition, one it was in Rio de Janeiro, and at summer time, the room temperature may be more them 120F)
Could someone confirm that please ?
Thank you very much !
JL _______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com http://seven.pairlist.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
_______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com http://seven.pairlist.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
Electrolytics usually. Make sure to check that it is set for correct line voltage. On Mar 5, 2013 1:35 PM, "Jose Luiz Martins" <joseluizmartins@gmail.com> wrote:
Hi Folks!
Continuing to put back to life my old test equipment...
I stored my HP 1650A Logic Analyzer in working order about 6 years ago. I bought it used - I think it was highly used once the screen has signs of burn on it.
Yesterday, when I finished to fix my Fluke 9010A, I've decided to try the 1650A and nope...
The power source clicks and the voltages are not correct. 7V instead of 12V, 4,5V instead of 5V and oscillating.
I have not experience in PS repair, but someone told me that the electrolytic capacitors may be dry due the time it was stored (as well as de condition, one it was in Rio de Janeiro, and at summer time, the room temperature may be more them 120F)
Could someone confirm that please ?
Thank you very much !
JL _______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com http://seven.pairlist.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
_______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com http://seven.pairlist.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
Jose Luiz Martins wrote:
The power source clicks and the voltages are not correct. 7V instead of 12V, 4,5V instead of 5V and oscillating.
Clicking is a sign of current overload. Oscillation is a sign of too low capacitance, i.e. not enough smoothing.
I have not experience in PS repair, but someone told me that the electrolytic capacitors may be dry due the time it was stored (as well as de condition, one it was in Rio de Janeiro, and at summer time, the room temperature may be more them 120F)
Yes, that's quite possible. May be best to see if any electrolytics have begun to bulge on top. If so, replace then right away.
Could someone confirm that please ?
Another possible failure is tantalum capacitors. They fail short at any time, and will overload the supply. I had one fail today in a Tek scope module (5A22N). It smoked a resistor, too. Worth checking, if there are tantalums on the power supply rails on the boards of the 1650A. -- John Honniball _______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com http://seven.pairlist.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
Thank you all for the opinions and lessons... I've changed all output capacitors, some of them was measuring more than 50% of original value. For instance: 1000uF measuring 1600uF, 470uF - 700uF and so on... But the PS is continuing clicking and oscillating... So I've decide to remove the filtering capacitors (4x 470uF 250V) and now I have the correct voltages. But the voltages decreases a lot when applying charge on it (back on 1650A mother board). Tomorrow I'll buy new filtering capacitors and see what happens. Thank you guys, JL On Wed, Mar 6, 2013 at 7:27 PM, John Honniball <coredump@gifford.co.uk> wrote:
Jose Luiz Martins wrote:
The power source clicks and the voltages are not correct. 7V instead of 12V, 4,5V instead of 5V and oscillating.
Clicking is a sign of current overload. Oscillation is a sign of too low capacitance, i.e. not enough smoothing.
I have not experience in PS repair, but someone told me that the electrolytic capacitors may be dry due the time it was stored (as well as de condition, one it was in Rio de Janeiro, and at summer time, the room temperature may be more them 120F)
Yes, that's quite possible. May be best to see if any electrolytics have begun to bulge on top. If so, replace then right away.
Could someone confirm that please ?
Another possible failure is tantalum capacitors. They fail short at any time, and will overload the supply. I had one fail today in a Tek scope module (5A22N). It smoked a resistor, too. Worth checking, if there are tantalums on the power supply rails on the boards of the 1650A.
-- John Honniball
_______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com http://seven.pairlist.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
Techtoolslist mailing list Techtoolslist@flippers.com http://seven.pairlist.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
On Thu, Mar 7, 2013 at 1:15 AM, Jose Luiz Martins <joseluizmartins@gmail.com> wrote:
Thank you all for the opinions and lessons...
I've changed all output capacitors, some of them was measuring more than 50% of original value. For instance: 1000uF measuring 1600uF, 470uF - 700uF and so on...
A high value is perfect for an electrolytic no need to throw that away
But the PS is continuing clicking and oscillating...
Look for shorts
Dave Caroline _______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com http://seven.pairlist.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
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