Please help fixing Pioneer PDR-555RW

[afecu]

Hi folks,

Thanks for the good information in this thread, which I found via Google. I'd bought a supposedly-working PDR-555RW some time ago, and even after I replaced the leaking "supercap" at C205 on the main board and cleaned up the traces, it simply wouldn't recognize any media (it always ended up at CHECK DISC).

So following the suggestions above, I cleaned the back of the "function" board (it wasn't terribly sticky but it did feel like there was something on part of it), and then I replaced the 3 electrolytic capacitors (mine had only 3, C705, C711, and C739). And voila! It works!!

I don't have a capacitor tester, but my voltmeter makes me somewhat suspicious of the capacitor from C705. None of the capacitors showed any physical signs of problems, and they were all rated at 10v (the service manual shows they are all used to smooth the +5v power so they shouldn't have been stressed). I didn't measure any voltages beforehand, either, so I just don't know what fixed it - but I'm happy it's working now!

[jsd21hb]

I was asked if i could look at and possibly fix this unit for a freind of mine. I did as the others had and had no luck. so i called him and told him i was unable to fix the problem and he told me just to as i pleased with it. Before tossing the unit out i tried one last thing after finding a FREE service manual( which took me the likes of a few hours searching google). In the manual i found a procedure to adjust the rec gain on the mainboard. I didnt follow the instructions due to not having a laser power meter but i just turned the 2 pots 102 and 103 about a 32nd of a turn and tried to record. I was able to get a recording but with much static and skipping so i turned another 32nd of a turn and it got better so i went a 64th of a turn, and tried it and voalla. I fixed it. I just thought i would share my story to others about the pdr-555rw.

[BexDonder]

Originally Posted by Henshouse

Found this on another board:

Post #7
FIX FOR THE PIONEER PDR-555 CD RECORDER

Problem: Display blinks “Check” message when pressing the record button.

After hours of checking the main PC board I realized I was barking up the wrong tree. I finally narrowed it down to the function PCB, which is located behind the front panel. I did several things here and I’m not sure which one solved the problem. But it is working like new.

Upon removing the function PCB I examined it with a magnifying lamp and noticed the foil side was covered with a sticky film. I believe this was a substance applied to the board during production to prevent corrosion. It could have been residue from a drink spilled in the unit, but I’m not sure. I’ve heard of coatings like these becoming conductive with age.

I removed the sticky substance with a spray solvent. You can use an electric components solvent, such as Bonafied made by Drummond America, or similar. I used a can of Birchwood-Casey Gun Scrubber, used for cleaning firearms because that’s all I had on hand.

After spraying both sides I noticed a light brown reside that had run off unto the paper beneath it. I then cleaned around the main IC with a fine brass brush (also a gun cleaning item made by Hoppes) an old toothbrush might do as well. After that I sprayed it down again and let it dry in front of a fan.

The next step was to replace four electrolytic capacitors (the only ones on the board). There are two 16v 100uf, and two 16v 47uf.

What fixed it? I’m not sure. I don’t have a capacitor checker, so I don’t know that these caps were bad. In the process of removing the board I disconnected a few ribbon cables. It is possible that breaking these connections alone resolved a static issue. I tend to think it was the sticky coating. Some Yamaha products from the mid-80’s, such as the SPX90 had this coating problem. However it could have been a spilled drink. The way the bonnet fits to the panel would allow the fluid to flow right onto the function PCB.

Anyway, it works great and I hope you have the same good outcome.

Hmmm... I originally wrote that after hours of troubleshooting my PDR-555 a few years ago and posted it here at diyaudio.

~Tim

[stephensank]

THE NUMBER ONE THING that goes wrong with PDR-555RW(aka PDR-19RW, PDR-V500, HHB CDR-850, Fostex CR300), and almost the ONLY thing that goes wrong is a STUPID part choice made to fullfill a USELESS function. Otherwise, fantastic recorders.
In order to maintain syscon memory in case of power outage, so that you don't waste a $0.90 cd-r if power goes out in the midst of recording, Pioneer chose the WORST POSSIBLE memory backup capacitor- a vertical mount Elna gold cap, usually 0.1F/5.5V. This horrible little cap likes to LEAK corrosive electrolyte, which creeps around the top AND bottom sides of the circuit board, and can cause random corrosion in about a 3 inch radius around the cap. FIRST STEP: Remove the cap & DON'T replace it. Leave the spot blank. It's a useless part for a useless function that NOBODY will ever miss. SECOND STEP: Very carefully examine traces for sub-enamel corrosion(trace will be darker), scrape away the enamel & corrosion to expose shiny copper, then either solder over it and/or apply an electrical insulating enamel/sealant. THIRD & HARDEST STEP: The corrosive electrolyte LOVES to attack the metallised(vapor deposition) through-holes that pass current from bottom to top of board & vice-versa. Using MAGNIFICATION, carefully examine all through-holes on main board that are within 4 inches of the removed cap, and repair ANY that are at all showing discoloration pitting under the enamel. To repair these, you have to poke through each one with a very sharp, thin, needle-like implement, then run a wire(a strand of a stranded wire, usually, to be thin enough) and solder to each top & bottom circuit trace joined by the hole, by scraping enough enamel off of each trace to provide solderable area.
Once you have spent 1 to 4 hours repairing the damage caused by that usesless, stupidly chosen Elna cap, the player will work flawlessly 99% of the time(unless you missed a bad through-hole or two). The other one percent is either a)the platter has slipped down the motor shaft slightly, easily popped back up into range, or b)the ribbon cable connecting the laser to the servo board needs to be unplugged & replugged at each end to clear minor oxidation. Pretty much nothing else ever goes wrong with these units.

[afecu]

Hi folks,

I posted that the front-panel capacitor fix helped my PDR-555RW also. It did--but only for a little while. Now, it again won't recognize any media, and after reading stephensank's great posting above, I'm sure it's because of the corrosion problem. On mine, it looks like it may have affected a couple of the leads from the microprocessor chip, and it's more than I think I can fix myself. (And did you know that a few of the through-holes come out underneath the bigger chips??)

I'm getting a PDR-509 instead. I checked and it uses a different type of battery-backup capacitor.

Stephensank, I also wasn't aware there were pro versions of these units. Must be a real bummer to have one of those with the leaking capacitor

[stephensank]

Unfortunately, although the PDR509/609 eliminate the faulty & useless Elna memory cap, these successor models are ONLY useful for direct-digital input/output, since a)the audio circuits & a/d & d/a conversion are crap by comparison, and b)both use a switchmode power supply, a source of HF noise & potential failures. So, I'd only recommend if you use it only for direct digital-to-digital recording, sadly. I'd much more strongly recommend you look for a PDR-05, 04 or 99. These all use the PD65 stable platter mech, but with a much more robust laser(whose lens almost never falls out like the PD65 & other Pioneer players were prone to) &, of course, recording ability(cd-r only, but who cares about cd-rw?). Although these do have an Elna memory cap, it is smaller & less corrosive, so removing it(you can just chop it's leads from top side of pcb) is usually all it takes to make for a really reliable recorder, and, of course, a SUPERB playback transport. The audio & ad-da electronics are also hugely better than the PDR-509/609, and even uses seperate power transformers for control/servo & audio/ad-da sections. Also can be had as Fostex CR200 & HHB CDR800, which remove the limitation of needing 'audio' cd-r blanks, since they are pro versions. If you shop for a currently working well unit, you can pretty near 100% count on simply needing to clip out the memory cap.

[afecu]

A correction to my posting above: The corrosion in the PDR-555RW is around the ATIP decoder chip (not the microprocessor), and in fact the error code indicates it can't read the ATIP. I haven't been able to fix it yet. I can still use it as an A-to-D or D-to-A converter though.

Stephen, it looks like the PDR-509 and -609 are not the same. The 509 has a traditional power supply (and the heat sinks on the 5 volt regulator chips look a lot more robust than on the 555RW). The 609, according to the service manual, does have the switched mode power supply. The ADC and DAC chips aren't the same either - here's a list -

555RW, V500, 19RW: ADC AK5340-VS / DAC PE8001A; the 19RW also has a PD0236AD - "Hi-Bit IC"
509: ADC PCM1800-1 / DAC PCM1716E
609: ADC/DAC: AK4524VF

(Curiously, it appears that at least some European versions of the 509 and 609 use a PE8001A DAC.)

I do find CD-RW's useful (and my analog recording is mostly going to be from cassette tapes, at least at this point), so I don't want to go with the PDR-04/05.

P.S. The HHB CDR-830 is a PDR-609?

[stephensank]

Now that I think about it, I have not actually worked on any PDR-509, and simply assumed, since the thing was such a piece of crap(relative to the 555, etc.) that the HHB CDR830's I've worked on were 509's. So, apparently, the 609(aka CDR830) is the piece of crap, and the 509 may actually be quite decent(unless it actually uses the same Elna memory cap, which I now don't know that it doesn't). Rather strange.
I've been quite lucky with the many 555/19RW/V500 main boards I've rescued from Elna cap damage, in that I've yet to have any of the corroded through-holes be buried under a chip.

[afecu]

Stephen,

The PDR-509 does use the same type of supercap as the 609, a double-layer carbon cap, not the Elna-type. (The one in the 509 is 1F/5.5V, the same value as the Elna cap in the 555RW; the 609 has a different design, with two of them, 0.22F/3.3V and 0.1F/5.5V).

[afecu]

Hi all,

I thought I'd come back and update folks on my results with these units.

First, I picked up some tools Stephen recommended, a fiberglass pencil (for cleaning the traces) and an acrylic-based CircuitSealer pen (for protecting them), from MCM Electronics.

I then went back to my original PDR-555RW, cleaned all the visible corrosion on the traces, checked continuity and repaired a couple of breaks, and tried it again. NADA. It still does not recognize any media, though I can see that it moves the laser up and down and it recognizes when there is no media present. I still think the problem is in the ATIP decoder, but I'm at a loss to fix it. I haven't done an exhaustive voltage check, but the spot checks I've done don't show any obvious problems.

I got another PDR-555RW (cheap). This time I knew to test it before I bought it, and it worked. The Elna cap had leaked, so I cleaned up the traces and coated them, also replacing the Elna supercap with a Panasonic of the same value (I also spotted one of these - the Panasonic - in a Sun Fire server - so I hope they are more reliable!). I had to increase the PB.PWR adjustment by about 1/32nd turn to get reliable burns on current CD-R media, but otherwise it worked fine. Curiously, the main board on this one has an added resistor on the backside, apparently connecting a couple of electrolytic capacitors by the CDR servo amp IC (IC247), and is missing jumper J203 on the front side. It's got a Pioneer Refurbished sticker on the case. This one I sold to a co-worker who's going to use it to digitize some LP's.

I got a third PDR-555RW (cheap). This one also works, and the Elna cap had not yet leaked. I replaced it with a Panasonic anyway. I'm keeping this one myself.

One note - the volume assembly on the front panel (top right) was very loose on a couple of these units. It's fastened from the front, and you just have to pull off the knobs to get to the nut.

I also have the PDR-509. I was able to make an audible improvement to the sound by replacing two op amp's. It had NJR4558's and I replaced them with 4565's, the same as the 555RW (and 609) use and with much better slew and bandwidth characteristics. I find the digital input level adjustment on the 509 useful, and it's also got a brighter display and a better remote, and it does have the conventional power supply.

One thing I've noted is that the CD-R's from all of these units don't test so well for errors. (No unrecoverable errors, but the general error rate is moderately high, and it doesn't appear to depend on the media.) You may want to duplicate anything important. Stephen, do you know if the "stable platter" models are any better in this regard?

And finally, I feel sorry for folks buying the PDR-19RW's lately at very high prices. The service manual says it has the exact same main board (the servo digital assembly), so presumably it has the exact same Elna supercap :-( , And aside from cosmetics, it's essentially a 555RW with a "Hi-Bit" IC added in the DAC, and the rest of the audio path is the same...