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Im a complete rookie at this…any help is greatly appreciated…Im overwhelmed by the info required…
I contacted Digikey and was given a link for capacitor ID…used that to get what I could from the Caps….this is for an old Laserdisc player power board thats dead…I tried sorting thru the catalogue …forgetabout it…Im lost…lol….I have only removed 2 from the board to access the info on one that was hidden …2 kinds total…I have pics of the board ,butt would rather not remove all of them at once…Im certain to screw this up if I do…
There 17 total and 13 unique caps .and 2 types(by looks) .this is from the 2 types.
ELNA 9644. 10v. 1000uf 85 degree. 10.3mm dia. 12mm Hi. 5mm board opening
The other type has less info
Nippon Chemicom KLG. 72R118(on top of cap) 250v 180uf. 105 degree 22.2 mm dia. 30.9mm Hi fixed pins (cant bend)Brown one in pic
As I said …Im a complete neophyte at this…wish Id taught myself electronics in the early 90s rather than computers…lol….so be gentle…lol…
I will provide any pics of info that I can gather
Thanks
Roger
It’s very likely that most, or even all, of the capacitors on the PCB still work fine, so I’d never blindly replace them all. But since you don’t know how to troubleshoot a power supply, it’s worth a shot in case all that’s wrong is some bad electrolytic capacitors.
To find replacements you have two choices:
The easiest is to ignore all the very rarely important specs and simply order replacements based on voltage, capacitance and size.
Example, the first part shows 250V 180uF
On the search page select those values and check the “In Stock” check box and click “Apply All”.
You’ll get 11 results that should work electrically in the circuit.
You then need to choose a part based on the physical size (diameter, height, lead spacing).
Lather, rinse repeat for all the electrolytic capacitors on the PCB.
Tip: if you get no result you can almost always safely increase the values by 50%. So for this first part you could select all values from 250 to 375 Volts and 180 to 270 uF.
The second method is to first locate the manufacturers data sheet for the exact parts. Then you use extra specs, with acceptable deviations (eg lower ESR, longer life) to narrow down the results to the optimal replacement. This level of specifics is almost never needed, one notable exception is very high cost high precision and accuracy electronic measuring instruments.
Hey Paul:…you are correct…the player is 30 yrs old, (caps do dry out ,or so Ive read) ….Im finally getting comfortable with an ESR meter…/a couple of the caps have values double of the charts numbers…/Wouldn’t think that would be what killed the board….its powered on twice ,played discs ,then unplugged ,and tried later…nada for power….whatever it is…its intermittent… ,let it set for a coupla months and again I get zilch for power (long story on why I let it sit) think its permanently dead now….guess I need to try a few YouTube video classes on troubleshooting power boards…Im too old for this…it makes my brain hurt….lol….
Roger
First I do a visual inspection for discolored or deformed parts including bulging caps. Then I check output voltages with a voltmeter followed by a check for excessive ripple with an oscilloscope. Next intermediate circuit points are checked for voltage and ripple. That will identify target suspect parts and I’ll pull those parts and check their fundamental property. Resistance of resistors, capacitance of capacitors, conductivity of semiconductors. With inductors I start with the DC resistance before checking inductance.
Nearly 100% of the time, by this point the bad parts have been identified, replaced and the system is working correctly.
If its not fixed at this stage then I might need to perform more obscure tests. Only once in my 50+ years of troubleshooting and repairing electronics have I needed to check the ESR of a capacitor. It was an AC coupler in a TV, it had passed capacitance tests, and was blocking DC, but it was at the part of the misbehaving sub-circuit. I measured the ESR and it was 10x the manufacturers spec.
50+ years?..youre as old as I am…lol….the ESR was the limit of my knowledge…recommend on a site that has the smartest folks in LDs ,.not electronic troubleshooting…Caps are a common problem seems the first strike for LD players …I did visual first ,no discoloration…no bulging or leaking….I have an oscilloscope ,use it to align the laser pickups…would know where to start …….All the other …checking output voltage/ripple is waaay over my head at present….question for me is… do I try to teach this old brain new (difficult) tricks or try and find someone to do it….Ive recently moved/retired to N E. OK…long drives to a city…guess Ive got lots to think on…I would put it on a shelf ,butt its a very rare (I collect high end LD players…maybe 20 of this model exist) high end unit…worth $1200-1500…much to consider….
I appreciate your help…
I will ask a last question/help…with the power coming and going as it is…works ,then it doesnt …what would you guess it to be?...only parts on the board I recognize are the usual…caps/trans and a transformer…
Thanks Again…Now get some sleep….unless youre like me….Rust Never Sleeps
Roger
Woah that’s one valuable piece of relatively recent (non-antique) piece of gear. It’s a horse of different color, normal electronic repair rules do not apply.
With gear like that, and 1960’s to 80’s home audio components, the value is based almost entirely on the niche buyers market. In those markets arbitrarily replacing all the electrolytic capacitors increases the value significantly even on a non-functioning unit.
So you can’t go wrong putting in $30 or less worth of electrolytic capacitors as the first step toward getting it working again. You may even get lucky and it turns out to really just needed a replacement capacitor or two to work correctly again.
Not sure I’m looking at this right, but a couple of the caps do look like they’re bulging a bit on the top. I’ve re-attached one of your pics with the suspects circled. The crosses on top don’t look straight across like the others, but appear to have a curve to them, leading me to believe they may be bulging slightly. I could be wrong, (probably am) but wanted to point this out in the off chance it helps.
Yea Paul…My thoughts exactly….Ive got the word out for someone local that can handle the diagnosis….or maybe give advice…Teaching myself wont be easy….Ive collected these silly things for 20+ years…have 3200 Discs also…When I tell people about it ,they get that …what? look on their faces….lol…With my collection…this wont be the last time I need to repair the electronics…I have a Theta and a very desirable McIntosh that are dead also…bought them for parts if needed….
My babies…12 0f the top 15 finest(subjective) ever made …total value….12K+ .recently moved in…just finishing the shelf unit for them…the one in question…3rd down on the right…
wildwall4, I was just wondering, since it stopped so abruptly, have you checked the fuse?
As for the caps, if the top feels bulged, or they appears to be leaking, they should be replaced.
Yes,fuse was first up …its also powered up twice then died after unplugging ….theres something unique to late model Pioneers (Enlightened Audio built from)…its called an Arc Suppressor…basically a circuit breaker…according to the folks at LD Database ,it will blow fuses ,you can just clip it out…For reasons beyond me…it doesnt affect the board operation other than the fuse(s) I havent identified it yet…will attempt to find out more tonight…and the Caps all look fine…kinda of an illusion because of the cross cut in the top of them ,causes it to look bulged at certain angles…
R
Hey Kristof….Ive been emailing with Paul about this …If your interested you can check our emails…It looks to be something other than the Caps…still unknown…Ive got beau coup research to do ,before doing anything…
Just the same …Thanks for your reply…you guys Rock.
Roger
I appreciate the help…Thanks….and Im kinda stubborn …its a very valuable one…It will get fixed…….if your interested…Ebay has about a 1000 for sale…with up-conversion ability of the new TVs ,even they lower end ones produce a good picture…fairly cheap…….if you need advice on that…Id be happy give it……
Im certifiable…meaning …nuts about them….if ya didnt see my email to Paul…heres my collection …the one in questions is 3rd down on the right……Im still moving …a year+ later…lol
Some of the finest ever made…
Thanks Again
Roger
Hey guys…Paul?..David…?..didnt know for a bit ,that I was talking to multiple Techguys….
So Im gonna replace the caps…I know from what Paul told me ,a ESR meter isnt the best for finding the boards problem…butt its what Ive got ….2 Caps are 3-4x over value…Im gonna take a flyer and do all of them…once againn,my lack of knowledge is biting me in the butt…when I search Caps …I start with about 114k+ results…then I search this group and get many results…First question…how do I know if Im picking the correct one,.Example …50v 10uf…105degree(was suggested over 85)…highest hour rating?.. and by size…height isnt an issue ,butt Dia is in many cases…butt I dont know the ratings needed…Ohms?..Impedance?..many have no rating for these while other have many…Next question…the Maker of the Caps…Ive put 3 makers per Cap in my Cart ….who has the best quality Caps?..Ive chosen names I know + an unknown or two…mostly…Rubycon…Panasonic…and Wurtz.(seems highest priced and hours)….all the different ratings have me stumped…they arent expensive(generally) I could buy 3vtypes each if needed …butt why should I….
Anyway…any help is greatly appreciated
Roger
Here is an example of the 3 makers…all have different impedance and Ohms…
