Finding the fault in the Technics SL-PG400A CD Player
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- เผยแพร่เมื่อ 22 ส.ค. 2024
- Previous video: • Technics SL-PG400A CD ...
At last I have found the fault in the Technics SL-PG400A CD Player. While it is too late to save it, this is good to know for future repair projects.
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Previous video (watch this one first!):
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First rule of repair is check voltages. My second step is check capacitors and ripple on v+ to chips. This has saved me hours of time when it comes to repairing vintage gear.
Regarding "sourcing parts from abroad": These players (the models with the 'A' suffix) were made in Germany. Matsushita had founded an extra company for this production (that is actually named on the back of the players). So it made perfect sense to source parts from Europe. The Japan-made models (without the 'A' suffix) did not use Philips mechanisms.
Thanks for the info!
NICE! Now I am gona fix mine after all these years! Shame you already scrapped yours...
TNX! I measured that cap with Fluke and it showed 15uF. I have same kind of measurement instrument you have, which I bought from AE and it told the same.
Now my player starts playing much quicker than before.
Thanks for the video. After 30 years of regular use, my 420A failed.
I simply replaced the capacitor and...voilá. Like New.
I am glad this video was helpful :) I have since come across another Technics CD player. It too had three bad capacitors on the servo board under the mechanism. Good to know!
Thanks! I had the same faulty capacitor on my SL-PG440A. Now it plays like a champ again!
You are welcome, I am glad this video was helpful :)
Thanks for this video !
I have a Marantz Cd75 from ~ 1987 with a similar issue and struggled for a year to find and fix a very similar isue… As you probably know Marantz was actually owned by Philips in the 80s so basically the Cd75 was a Philips cd player. It doesn’t have a CDM4 but a CDM2 inside but the servo board does look similar and most importantly it had one of those blue Philips electrolytic capacitors.
Checked it and just like yours: low capacity, high esr, high leakage. Replaced it and problem solved! 😁
Thanks again and keep up the good work 👍👍👍
I am glad you found this video helpful :)
It's never a loss when you learn something new from the experience 😉
These videos are very informative. Well done. Thoe folks talking about laser adjustments were probably thinking of Sony KSS mechanisms that do have 2 potentiometers on the laser pickup.
Dear DrCassette, many thx for this video - and also to the community. I had an old Technics CD Player SL-PG540 A and your tip was a great help. In my player modell the sound of the error was the same like you recorded. So I only need to buy 47 uF 25 V Axial Elko and -after replacement - could instantly start and use it as before. Very well explained. Happy XMAS.
Hi everybody! Today I replaced the same capacitor on my SL-PG400A. All problems solved. Thanks @DrCassette!
You are welcome :)
I recently bought an sl-pg400a, mine still worked great but i decided to swap it out anyway. Mine measured even worse at 17uF so perhaps it wasn't the only fault with yours. To anyone doing this fix/mod there is a typo in the service manual, it's a 25v capacitor and not a 2.5v like listed in the component list.
Very interesting that this board does only have the 2501 cap and not the two identical 2502 and 2503 caps I have on my SL-PG400A. There has been an evolution of these servo boards and some later models like the Technics SL-PG540A miss the option to adjust the laser focus. But you can never be sure if there's the original drive and board inside the used cd-player because they can be replaced very easy
Technics SL-PG530, it has the very same board with a single blue axial caps and two pots for laser current and focus offset.
I might be wrong, but that capacitor is in the laser Diode driver circuit thus causing a lot of problems if it goes bad. Those blue axial capacitors are almost 100% guaranteed to be bad. I think Philips itself knew they were of poor quality because in critical circuits (PSU, audio pre-amp, ...) they were using Japanese made caps by Nichicon or Elna.
These axial capacitors look like they were made in the 70s, most likely because the whole production process had not been changed since the 70s...
@@DrCassette and yet were in production until the mid '90s ... I checked the service manual and C2521 is connected between the Laser ON signal and ground. The laser ON signal drives the base of a npn transistor which send current into the laser diode. Purpose of the cap is to smooth the laser activation transient, but if it goes bad, not enough current goes through the laser itself.
That certainly explains why it seemed like the laser itself was bad...
@@DrCassette I have several hundred of them... NOS
I see a TON of those bad Phillips axial blue caps. I replace every one i see. I have only found them to still be OK a handful of times. (I'm an auto mechanic, I repair German made vehicles mostly, they used those specific caps a TON)
The people who commented about the adjustment on the laser itself are or were probably not aware that some early models had the adjustment in an easy to adjust location on the PCB instead of on the actual laser....
My Technics CD player is older than the one that you have there and it's adjustments are also on the PCB...
Die Philips CD Laufwerke sind bis heute die Besten. Und ich rede von fast 30 Jahren.
Natürlich ist das Zwischenrad für die Schublade ärgerlich.. Ich glaube auch nicht, dass es gewollte Obsolezenz gewesen ist.
Nette Grüsse aus dem Oldenberger Land 👍 👍
Nice fix tip, thanks: Capacitor c6501 found on my particular SL-PG400A to have an esr = 53ohms, C= 21.3uF, & Vloss= 9.9%
Position is C2521 not 6501.
@@marcelmojzis4374 Many thanks Marcel for ID correction on this capacitor marked on PCB. The adjacent '6501' component (an 'unfitted' IC ) position was inadvertently mis-identified🔎
8.2% voltage loss.... Bad ESR also, it's definitely a leaky capacitor! Definitely a problem maker...
Always keep an eye on the Vloss value... This gives you the amount of DC leakage current of the capacitor...
as this stuff gets older the more and more I see bad capacitors but in the day when working on Sony TV's I would find lots of bad ones .
@@richardbrobeck2384 there was a period of time when modern capacitors were really bad! That's something that you have to keep in mind when servicing equipment! You can't just take ESR measurements! You have to check for leakage current also... Leakage current is the biggest trouble maker with capacitors! Passing DC current to somewhere it's not wanted..
@@PeterMilanovski For sure I use a Sencore LC meter
@@richardbrobeck2384 fantastic! Do you ever compare the DC leakage of an old capacitor to an identical new one?
Most people who have an LCR Bridge Meter don't take advantage of the DC leakage measurement capabilities of the device! I kinda get the feeling that people just purchased the tool for the sake of having the best equipment! But when they use it to test a capacitor, they check capacity and ESR and only use those two measurements to decide if the capacitor is good or not!
I have found that just by looking at the capacity of the capacitor, you can get a good clue as to what it's condition is in. If it's capacity is way too low, it's dry and should be replaced, if it's capacity is over it's rated value, it's leaking DC current and it should also show low ESR and should definitely be replaced!
We know that resistors and transistors can have a very long operating life, but capacitors don't! They never really have! So it should be no surprise that if an electronic product has a problem, it's either going to be a capacitor or caused by a capacitor! But not everyone understands this! And there isn't many channels that emphasizes this, it's always ESR, they always do an in circuit test! Everything appears to be fine but the problem is still there! And they can't work out why! I find it frustrating and I try to make a mention of what and why and how they didn't find the problem in the comments section but people seem to find it difficult to grasp what I'm trying to get across! I'm just trying to be helpful so that they can fix whatever they are working on faster and I can just enjoy watching someone else working! But when the problem is obvious to me and the person doesn't know, it's just frustrating!!! There's a few channels that I have stopped watching because it's just too difficult to watch! I would never send my equipment to them to repair! It's just going to come back to me only to die another day! (There's a good movie title in that, I swear!).. and yet they still get customers! Do these people like having equipment problems every few months or something? Yeah I don't know.
@@PeterMilanovski I agree with you and my background training is electronics I took electronics in high school and in college right out college I worked for the repair business that I have owned since late 80s take that Cd player Each Capacitor was hand picked to work in circuit just like when repair item I go through the Data sheets on capacitors on the Mouser Electronics website Also another device i find very handy is the Huntron tracer .
Your vids have me hoarding odd bits of old stuff and yes I have repaired several nice pieces with thos parts that would have found the trash can
avevo lo stesso problema in un modello SL-PJ28A e ho risolto cambiando i condensatori. grazie mille!!
You are welcome, I am glad this video was helpful :)
I love this channel! If only you didn't hurry up so much to tear apart this player maybe it would be now working. Anyway, good follow up video!
Hi, thanks for that video. I have a Technics from the SL-PG series and understand that these Phillps axial blue caps are often faulty (even when new?). So is there an other manufacturer that makes them and where could I buy one of those? Thanks!
Capacitors are standard components, replacements are readily available. Make sure you get the same capacitance rating, and the same or a higher voltage rating.
@@DrCassette Thank you for the info, I'll have a look (seems like Panasonic is a safe bet, from what I've read).
Capacitors are a lot less critical than people try to make you believe. Just don't get any no-name ones from dubious sources...
@@DrCassette OK, will do. Thanks again!
Very good and funny videos bring a great sense of entertainment!
You gave up pretty quick xD.
Then there's me, I've been trying for about a month to repair an old Denon CD player.
You do realize your comment is rather insulting? I allocated one afternoon to repairing this CD player, I did not have it fixed by the end of that afternoon so that was the end of it. This has nothing to do with giving up. I would not waste a month of my time on a CD player.
@@DrCassette don't be insulted, he's merely referring to his own disappointment at not being able to fix the one he has. Being insulted will waste your energy and make you feel sad.
BTW I like your videos and approach to repairs. Thanks
@@DrCassette How was my comment insulting? lol.
I even laugh at my own ass because I haven't fixed it for so long xD.
I've been subscribed to you for close to 10 years, never expected you to be such a snowflake and get "offended" by my comment.
Lighten up dude ❤
@@GoldSrc_ Lost in translation I think, the humor was blindingly obvious to me.
I have a Sony CFD-5 boombox from 1989 which has the Sony D-50 cd player builtin and it tries to read cds but fails. Tried adjusting the focus pots and the pot on the laser but no luck.
I have a Technics SL-P202A Recently didn't want to spin. If i give it a spin by hand it starts up. Motor seems weak i tried adjusting laser pots but no difference.
I just opened it up (need to remove front face) It has 2x of these 47uf caps in same style. I'm about to test them now. Showing 19uf and 21uf. Not going to bother with the esr meter. Changing right now.
And, the results, just in. At first it still needed help but when it did start it was skipping. Then i remembered i had adjusted the focus and current. Didn't want to hook to scope too lazy. I turned current just up a bit from minimum (forgot to mark original pos.) Then started to turn focus antiC from where i had left it, got better so tried another twist was fine, then a big twist to the left and was still fine. I'll do a bit more experimenting then call it a day. Thanks for the help. Was no need to remove the board on this model, enough acces from the side, easy to solder, leave a few mm from the old legs. polarity marked on the board silk screen print. For anyone wondering, the thin part on the Philips capacitor does not mark the negative. There is a very thin black line, also if you look carefully at the cap one end has a rubber bung which is + the other end is the actual can and it's all metal at that end which is the - or shield.
Now. Does anyone know how to tune up the laser on a SL-PS770D? The old SL i just fixed reads right over skips or rather doesn't skip on parts of the CD where the SL-PS770 does skip. No visible manual adjustments. I'll look for caps but perhaps it's just an inferior CD player. For this reason i'm very happy to have the 202A working again.
Thanks to everyone who found the bad caps!
PS. confirmed that by turning the focus laser too far AC resulted in the disc not wanting to spin up, approximately turned between 90 and 120 degrees CW from minimum. At least seems to be working fine in this range, i'm somewhere in the middle of the working range, a bit more to the minimum value side perhaps as too far CW and it was skipping to far AC and it just didn't want to know after around 90 degrees of clockwise turning it seemed fine, i think i left it at around 100-110 degrees from minimum.
A very interesting info, thank you try to clean up lens without result, but 47uF and voltage please ?
In 2:50 you can see 16V marked on capacitor (at the right edge).
This capacitor is 25V 47uF, I put 50V 47uF standard electrolic capacitor, because I didn't had 25V and it works fine, cd reads instantly
I have several tascam guitar trainers cd-gt2 which use a tascam cd drive mechanism, the cd players usually work for a few moments or less and another won't read the disc, the caps are all smd in starting to think that may be the issue
Those Blue axial style caps are the WORST. They are almost always BAD. They are used inside the modules in Mercedes-Benz vehicles as well, and every single one I have found has been dead!
true - those Caps are bad in every CDs
First of all congrats for your videos. If I may ask, do you by any chance kept the original cd main board? I have a sl-pg500a with a problem on the main board, and was looking for a replacement one. Thank you.
I did not keep the main board, so unfortunately I can't help you.
@@DrCassette thank you for you attention. Best regards.
Great job. 👍
Thank you :)
Does anyone know how to tune up the laser on a SL-PS770D? The old SL i just fixed reads right over skips or rather doesn't skip on parts of the CD where the SL-PS770 does skip. No visible manual adjustments. I'll look for caps but perhaps it's just an inferior CD player. For this reason i'm very happy to have the 202A working again.
Hi, I got same problems , same machine, which capacitor can I replace? can't find the same one. Is a normal 47uf 25v?
Thank you
You can use a regular radial capacitor and bend the leads. Only the 47uF has to be exact, the voltage can be higher than 25v but not lower but it's better to stay close to 25v. It's a standard value so finding one shouldn't be hard.
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