Tektronix 2445 Readout is no good , video included
in [Repair]
|
Prev: Avometer Model 8 repair
Next: sharp lcd 5 inch LQ5RB43
From: NetSpid3r on 19 Nov 2007 12:01 On Nov 19, 12:33 am, Jim Yanik <jya...(a)abuse.gov> wrote: > "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote innews:a089d234-8202-4980-a6d9-ae53bee0e1b7(a)41g2000hsh.googlegroups.com: > > > > > On Nov 17, 3:08 am, Jim Yanik <jya...(a)abuse.gov> wrote: > >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote > >> innews:28ac4545-7a53-4594-83d8-910b6ccf1d63(a)e4g2000hsg.googlegroups.co > >> m: > > >> > On Nov 16, 6:57 am, Jim Yanik <jya...(a)abuse.gov> wrote: > >> >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote in > >> >> news:19dc4e5b-d326- > >> >> 4c17-9bc9-bb21fa6f0...(a)a28g2000hsc.googlegroups.com: > > >> >> > Jim Yanik wrote: > >> >> >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote in > >> >> >>news:1195075563.961231.101880(a)57g2000hsv.googlegroups.com: > > >> >> >> >http://video.yahoo.com/video/play?vid=1466538 > > >> >> >> > The readout looks bad , i can see jumpy dots ,instead of > >> >> >> > clear numbers as in the other 2445 . > >> >> >> > i replaced those 3 47uf caps on the A5 board (control board) > >> >> >> > , and it didn't helped . > >> >> >> >http://img110.imageshack.us/img110/2372/image015pn5.jpg > > >> >> >> 2445 non-B scopes have separate R-O boards. > >> >> >> the signal from them feeds into the vertical on the main bottom > >> >> >> board. try swapping the readout boards. > >> >> >> IIRC,there's also a pot to adjust R-O crawl/jitter. > >> >> >> see the cal procedure in your service manual. > > >> >> >> On "B" models,the readout is integrated to the A5 uP board. > >> >> >> "B" model A5 uP boards are NOT swappable with earlier versions. > > >> >> >> -- > >> >> >> Jim Yanik > >> >> >> jyanik > >> >> >> at > >> >> >> kua.net > >> >> > tried play with jitter , didn't do the trick ... > > >> >> > and you are right about A5 in the 2445 , the R-O is not on this > >> >> > board , i just did a swap with a good 2445 A5 and got the same > >> >> > jerky readout . > > >> >> > what component is making the problem in the R-O of the 2445 ? > >> >> > caps ? or something else ? > > >> >> possibly caps,or a bad hybrid on the main board. > >> >> Does it twitch in the vert or horiz direction,or both? signal > >> >> trace solid,in both V and H axes? > >> >> This may be where you have to scope every decoupled PS supply > >> >> line. could even be some of those 0.1uf DIP caps that are all over > >> >> every board. > > >> >> -- > >> >> Jim Yanik > >> >> jyanik > >> >> at > >> >> kua.net > > >> > trace is solid , no trace problems . > > >> Is that a trace with a signal displayed,or just the baseline trace? > >> With a signal displayed,you can see any horiz jitter. > >> Without an input signal,you can't see any jitter in the horiz. > > >> > and one thing i noticed , when i control the read out intensity > >> > fully CW , the R-O shifts upwards ... > > >> I wonder if your CRT is maxed out on intensity.(grid bias) > > >> -- > >> Jim Yanik > >> jyanik > >> at > >> kua.net > > > Well , the read-out is good now , i replaced the power supply , and > > don't have jerky read-out . > > i guess power supply ain't that good . > > probably marginal electrolytics,bad ESR. > often,the PS is the source of trouble appearing elsewhere. > > > > > but i got another problem with this scope , the horiz is not good at > > some of time bases , some of them ok , but lets say 5u is drifting . > > i did CAL 01-04 , but got LIMIT warning in the horiz section , could > > not adjust as required . > > something is wrong , what i'm doing wrong ? > > All the parts for timing are on the sweep hybrids.try swapping the A and B > sweep hybrids,and recal.if the problem goes away on that range/mode,then yu > have a bad hybrid. > > -- > Jim Yanik > jyanik > at > kua.net Well , gonna try this after i'l find new U800 (Horiz amp ) just destroyed the one that was on the scope . the horiz amp got nothing to do with the timing ? do you know where i can find U800 ?
From: Jim Yanik on 19 Nov 2007 13:57 "NetSpid3r(a)gmail.com" <NetSpid3r(a)gmail.com> wrote in news:8e0393b6-bd6b-4506-9624-7eb217148256(a)f13g2000hsa.googlegroups.com: > On Nov 19, 12:33 am, Jim Yanik <jya...(a)abuse.gov> wrote: >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote >> innews:a089d234-8202-4980-a6d9-ae53bee0e1b7(a)41g2000hsh.googlegroups.co >> m: >> >> >> >> > On Nov 17, 3:08 am, Jim Yanik <jya...(a)abuse.gov> wrote: >> >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote >> >> innews:28ac4545-7a53-4594-83d8-910b6ccf1d63(a)e4g2000hsg.googlegroups >> >> .co m: >> >> >> > On Nov 16, 6:57 am, Jim Yanik <jya...(a)abuse.gov> wrote: >> >> >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote in >> >> >> news:19dc4e5b-d326- >> >> >> 4c17-9bc9-bb21fa6f0...(a)a28g2000hsc.googlegroups.com: >> >> >> >> > Jim Yanik wrote: >> >> >> >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote in >> >> >> >>news:1195075563.961231.101880(a)57g2000hsv.googlegroups.com: >> >> >> >> >> >http://video.yahoo.com/video/play?vid=1466538 >> >> >> >> >> > The readout looks bad , i can see jumpy dots ,instead of >> >> >> >> > clear numbers as in the other 2445 . >> >> >> >> > i replaced those 3 47uf caps on the A5 board (control >> >> >> >> > board) , and it didn't helped . >> >> >> >> >http://img110.imageshack.us/img110/2372/image015pn5.jpg >> >> >> >> >> 2445 non-B scopes have separate R-O boards. >> >> >> >> the signal from them feeds into the vertical on the main >> >> >> >> bottom board. try swapping the readout boards. >> >> >> >> IIRC,there's also a pot to adjust R-O crawl/jitter. >> >> >> >> see the cal procedure in your service manual. >> >> >> >> >> On "B" models,the readout is integrated to the A5 uP board. >> >> >> >> "B" model A5 uP boards are NOT swappable with earlier >> >> >> >> versions. >> >> >> >> >> -- >> >> >> >> Jim Yanik >> >> >> >> jyanik >> >> >> >> at >> >> >> >> kua.net >> >> >> > tried play with jitter , didn't do the trick ... >> >> >> >> > and you are right about A5 in the 2445 , the R-O is not on >> >> >> > this board , i just did a swap with a good 2445 A5 and got >> >> >> > the same jerky readout . >> >> >> >> > what component is making the problem in the R-O of the 2445 ? >> >> >> > caps ? or something else ? >> >> >> >> possibly caps,or a bad hybrid on the main board. >> >> >> Does it twitch in the vert or horiz direction,or both? signal >> >> >> trace solid,in both V and H axes? >> >> >> This may be where you have to scope every decoupled PS supply >> >> >> line. could even be some of those 0.1uf DIP caps that are all >> >> >> over every board. >> >> >> >> -- >> >> >> Jim Yanik >> >> >> jyanik >> >> >> at >> >> >> kua.net >> >> >> > trace is solid , no trace problems . >> >> >> Is that a trace with a signal displayed,or just the baseline >> >> trace? With a signal displayed,you can see any horiz jitter. >> >> Without an input signal,you can't see any jitter in the horiz. >> >> >> > and one thing i noticed , when i control the read out intensity >> >> > fully CW , the R-O shifts upwards ... >> >> >> I wonder if your CRT is maxed out on intensity.(grid bias) >> >> >> -- >> >> Jim Yanik >> >> jyanik >> >> at >> >> kua.net >> >> > Well , the read-out is good now , i replaced the power supply , and >> > don't have jerky read-out . >> > i guess power supply ain't that good . >> >> probably marginal electrolytics,bad ESR. >> often,the PS is the source of trouble appearing elsewhere. >> >> >> >> > but i got another problem with this scope , the horiz is not good >> > at some of time bases , some of them ok , but lets say 5u is >> > drifting . i did CAL 01-04 , but got LIMIT warning in the horiz >> > section , could not adjust as required . >> > something is wrong , what i'm doing wrong ? >> >> All the parts for timing are on the sweep hybrids.try swapping the A >> and B sweep hybrids,and recal.if the problem goes away on that >> range/mode,then yu have a bad hybrid. >> >> -- >> Jim Yanik >> jyanik >> at >> kua.net > > Well , gonna try this after i'l find new U800 (Horiz amp ) just > destroyed the one that was on the scope . > > the horiz amp got nothing to do with the timing ? > > do you know where i can find U800 ? > they aren't made anymore,and the only place you can get one is from another 2445/65 scope.IIRC,there was an Ebay seller who had some salvaged ones for sale,but the price was pretty high. -- Jim Yanik jyanik at kua.net
From: NetSpid3r on 19 Nov 2007 14:50 On Nov 19, 8:57 pm, Jim Yanik <jya...(a)abuse.gov> wrote: > "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote innews:8e0393b6-bd6b-4506-9624-7eb217148256(a)f13g2000hsa.googlegroups.com: > > > > > On Nov 19, 12:33 am, Jim Yanik <jya...(a)abuse.gov> wrote: > >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote > >> innews:a089d234-8202-4980-a6d9-ae53bee0e1b7(a)41g2000hsh.googlegroups.co > >> m: > > >> > On Nov 17, 3:08 am, Jim Yanik <jya...(a)abuse.gov> wrote: > >> >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote > >> >> innews:28ac4545-7a53-4594-83d8-910b6ccf1d63(a)e4g2000hsg.googlegroups > >> >> .co m: > > >> >> > On Nov 16, 6:57 am, Jim Yanik <jya...(a)abuse.gov> wrote: > >> >> >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote in > >> >> >> news:19dc4e5b-d326- > >> >> >> 4c17-9bc9-bb21fa6f0...(a)a28g2000hsc.googlegroups.com: > > >> >> >> > Jim Yanik wrote: > >> >> >> >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote in > >> >> >> >>news:1195075563.961231.101880(a)57g2000hsv.googlegroups.com: > > >> >> >> >> >http://video.yahoo.com/video/play?vid=1466538 > > >> >> >> >> > The readout looks bad , i can see jumpy dots ,instead of > >> >> >> >> > clear numbers as in the other 2445 . > >> >> >> >> > i replaced those 3 47uf caps on the A5 board (control > >> >> >> >> > board) , and it didn't helped . > >> >> >> >> >http://img110.imageshack.us/img110/2372/image015pn5.jpg > > >> >> >> >> 2445 non-B scopes have separate R-O boards. > >> >> >> >> the signal from them feeds into the vertical on the main > >> >> >> >> bottom board. try swapping the readout boards. > >> >> >> >> IIRC,there's also a pot to adjust R-O crawl/jitter. > >> >> >> >> see the cal procedure in your service manual. > > >> >> >> >> On "B" models,the readout is integrated to the A5 uP board. > >> >> >> >> "B" model A5 uP boards are NOT swappable with earlier > >> >> >> >> versions. > > >> >> >> >> -- > >> >> >> >> Jim Yanik > >> >> >> >> jyanik > >> >> >> >> at > >> >> >> >> kua.net > >> >> >> > tried play with jitter , didn't do the trick ... > > >> >> >> > and you are right about A5 in the 2445 , the R-O is not on > >> >> >> > this board , i just did a swap with a good 2445 A5 and got > >> >> >> > the same jerky readout . > > >> >> >> > what component is making the problem in the R-O of the 2445 ? > >> >> >> > caps ? or something else ? > > >> >> >> possibly caps,or a bad hybrid on the main board. > >> >> >> Does it twitch in the vert or horiz direction,or both? signal > >> >> >> trace solid,in both V and H axes? > >> >> >> This may be where you have to scope every decoupled PS supply > >> >> >> line. could even be some of those 0.1uf DIP caps that are all > >> >> >> over every board. > > >> >> >> -- > >> >> >> Jim Yanik > >> >> >> jyanik > >> >> >> at > >> >> >> kua.net > > >> >> > trace is solid , no trace problems . > > >> >> Is that a trace with a signal displayed,or just the baseline > >> >> trace? With a signal displayed,you can see any horiz jitter. > >> >> Without an input signal,you can't see any jitter in the horiz. > > >> >> > and one thing i noticed , when i control the read out intensity > >> >> > fully CW , the R-O shifts upwards ... > > >> >> I wonder if your CRT is maxed out on intensity.(grid bias) > > >> >> -- > >> >> Jim Yanik > >> >> jyanik > >> >> at > >> >> kua.net > > >> > Well , the read-out is good now , i replaced the power supply , and > >> > don't have jerky read-out . > >> > i guess power supply ain't that good . > > >> probably marginal electrolytics,bad ESR. > >> often,the PS is the source of trouble appearing elsewhere. > > >> > but i got another problem with this scope , the horiz is not good > >> > at some of time bases , some of them ok , but lets say 5u is > >> > drifting . i did CAL 01-04 , but got LIMIT warning in the horiz > >> > section , could not adjust as required . > >> > something is wrong , what i'm doing wrong ? > > >> All the parts for timing are on the sweep hybrids.try swapping the A > >> and B sweep hybrids,and recal.if the problem goes away on that > >> range/mode,then yu have a bad hybrid. > > >> -- > >> Jim Yanik > >> jyanik > >> at > >> kua.net > > > Well , gonna try this after i'l find new U800 (Horiz amp ) just > > destroyed the one that was on the scope . > > > the horiz amp got nothing to do with the timing ? > > > do you know where i can find U800 ? > > they aren't made anymore,and the only place you can get one is from another > 2445/65 scope.IIRC,there was an Ebay seller who had some salvaged ones for > sale,but the price was pretty high. > > -- > Jim Yanik > jyanik > at > kua.net i'l try to salvage ... the horiz amp got nothing to do with the timing ?
From: Jim Yanik on 19 Nov 2007 17:22 "NetSpid3r(a)gmail.com" <NetSpid3r(a)gmail.com> wrote in news:2328c2df-fd65-421a-a63b-340744a26727(a)b32g2000hsa.googlegroups.com: > On Nov 19, 8:57 pm, Jim Yanik <jya...(a)abuse.gov> wrote: >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote >> innews:8e0393b6-bd6b-4506-9624-7eb217148256(a)f13g2000hsa.googlegroups.c >> om: >> > Well , gonna try this after i'l find new U800 (Horiz amp ) just >> > destroyed the one that was on the scope . >> >> > the horiz amp got nothing to do with the timing ? >> >> > do you know where i can find U800 ? >> >> they aren't made anymore,and the only place you can get one is from >> another 2445/65 scope.IIRC,there was an Ebay seller who had some >> salvaged ones for sale,but the price was pretty high. >> >> -- >> Jim Yanik >> jyanik >> at >> kua.net > > i'l try to salvage ... > > the horiz amp got nothing to do with the timing ? > why don't you read the excellent circuit description that's in the service manual? -- Jim Yanik jyanik at kua.net
From: NetSpid3r on 21 Nov 2007 12:04
On Nov 20, 12:22 am, Jim Yanik <jya...(a)abuse.gov> wrote: > "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote innews:2328c2df-fd65-421a-a63b-340744a26727(a)b32g2000hsa.googlegroups.com: > > > > > On Nov 19, 8:57 pm, Jim Yanik <jya...(a)abuse.gov> wrote: > >> "NetSpi...(a)gmail.com" <NetSpi...(a)gmail.com> wrote > >> innews:8e0393b6-bd6b-4506-9624-7eb217148256(a)f13g2000hsa.googlegroups.c > >> om: > >> > Well , gonna try this after i'l find new U800 (Horiz amp ) just > >> > destroyed the one that was on the scope . > > >> > the horiz amp got nothing to do with the timing ? > > >> > do you know where i can find U800 ? > > >> they aren't made anymore,and the only place you can get one is from > >> another 2445/65 scope.IIRC,there was an Ebay seller who had some > >> salvaged ones for sale,but the price was pretty high. > > >> -- > >> Jim Yanik > >> jyanik > >> at > >> kua.net > > > i'l try to salvage ... > > > the horiz amp got nothing to do with the timing ? > > why don't you read the excellent circuit description that's in the service > manual? > > -- > Jim Yanik > jyanik > at > kua.net Well all good now , replaced U800 , replaced hybrids , timing is good . great , thanks . |