[rkg22]

This ' Post-Newbie ' thread is for Magnavox & Philips recent model DVR devices only. It is intended for those folks with a more advanced technical background who might like to perform some hands on updates or modifications to these machines. If you're handy with a soldering iron and not faint of heart, this thread would be for you. Post away if you have some valuable info or experience to share.


Applicable models are Philips DVDR-3575 & 3576, and Magnavox MDR-513 & 515.

 

[rkg22]

Here is some useful information & some modifications that I've learned, am doing, or have already done.


1 - Calibrate the free-running time of day clock. The clocks in these machines seem to be very inaccurate. All of my machines' clocks run very fast, requiring me to re-cal the clocks on a weekly basis in order to have accurately timed scheduled recordings.


For those utilizing the ' auto-update ' feature, you're out of luck with the older Philips DVD recorders, as these can only update their clocks using an analog broadcast channel. With the newer Magnavox machines, while these CAN perform auto-updates to their clocks, I have noted, at least in my market, that many of the stations' clocks are inaccurate to begin with.


For me, I have elected to perform manual clock updates, and to calibrate the clocks with a padding capacitor. I've done this on a trial and error basis for 2 of my 4 machines, so far ( the 3rd is in process now ), and have managed to get the clock accuracy ( extrapolated to long term ) down to plus or minus about 1 minute per year.


The crystal used to maintain the clock is X1502 on the machine's motherboard. This is a 32.768 kHz crystal, whose leads can be accessed from the top of the motherboard. There is also a handy ground jumper located near the crystal, allowing you to solder a small ceramic cap between 1 lead of the crystal and ground.


The first machine I modified required about 120pF in order to harness the accuracy. The 2nd machine required 100pF.


I've attached a photo showing the modification I made to accomplish this.

 

[jjeff]

It's kind of hard to tell from your photo but is the cap you added in series with the crystal or simply from the one side to ground? IOW did you have to cut the crystal's lead or just tack solder onto it's leg and then ground?

AFA the value of the cap, is it strictly a trial and error and if so how far were your clocks off to begin with to require a 100 and 120pf cap?

 

[ClearToLand]



Quote:
Originally Posted by jjeff /forum/post/21646358


It's kind of hard to tell from your photo but is the cap you added in series with the crystal or simply from the one side to ground? IOW did you have to cut the crystal's lead or just tack solder onto it's leg and then ground?

AFA the value of the cap, is it strictly a trial and error and if so how far were your clocks off to begin with to require a 100 and 120pf cap?

All the step-by-step details are in the Mega Mag FAQ thread, along with a PDF I created including both pictures:
When Does The Book Come out?!?
IMHO, this summary is a bit brief - great for those that have been following the topic all along, but, maybe (as you've proven) a bit sparse for someone reading it for the first time.


I had intended to abstain from posting here until rkg22 got all the 'fine details' sorted out (i.e. thread name, reserved posts, etc...). I'll delete this post after you read it.


As Leonard McCoy would say: "I'm a doctor, not a [email protected]#$% Jim!"

rkg22 needs to get his 'feet wet'.

 

[rkg22]



Quote:
Originally Posted by jjeff /forum/post/21646358


It's kind of hard to tell from your photo but is the cap you added in series with the crystal or simply from the one side to ground? IOW did you have to cut the crystal's lead or just tack solder onto it's leg and then ground?

AFA the value of the cap, is it strictly a trial and error and if so how far were your clocks off to begin with to require a 100 and 120pf cap?

hi jjeff...


the cap is placed in parallel with one side of the rock. the other side of the cap is tacked to the ground jumper nearby.


no need to cut any leads. just carefully ' tack-solder ' the cap to the crystal lead close to the board hole. for this stuff i use a small Weller Princess iron.


the existing circuit for the crystal has a small cap to ground on either crystal lead ( underside of motherboard ).


my lead choice was electrically arbitrary, but was chosen as it was the closest lead to a convenient ground jumper.


more dramatic results might happen if one chooses the opposite lead to pad with. mine just happened to work fine with the 100 or so pF caps i had on hand.


regarding cap value, i did it trial and error... add the cap, set the clock, wait 48 hours, check the clock, etc...


i have an uncalibrated freq counter, but can't get the thing to lock up due to probe issues. if you have a counter and can loosely couple to the crystal without loading it down, you could probably avoid the trial and error stuff.


rgds,

ron g

 

[rkg22]



Quote:
Originally Posted by ClearToLand /forum/post/21646470


All the step-by-step details are in the Mega Mag FAQ thread, along with a PDF I created including both pictures:
When Does The Book Come out?!?
IMHO, this summary is a bit brief - great for those that have been following the topic all along, but, maybe (as you've proven) a bit sparse for someone reading it for the first time.


I had intended to abstain from posting here until rkg22 got all the 'fine details' sorted out (i.e. thread name, reserved posts, etc...). I'll delete this post after you read it.


As Leonard McCoy would say: "I'm a doctor, not a [email protected]#$% Jim!"

rkg22 needs to get his 'feet wet'.

hi cleartoland...


in oder to satisfy folks, i'll try to change the title to DVDR... but i prefer DVR, since these things are digital video recorders, with 2 different transports used for the recording process.


i'll just use the title area as i post future stuff... really not too much i intend to mod with. my intent is really just to keep my 3576 machines from being obsolete...


but as i find things to tinker with, i'll tinker and post... i don't want to make this a major project. i just wanted to oblige wajo and not muddy up his original and most helpful thread with the heavier techy stuff that most folks might not be interested in dealing with... for me, it can be an escape, and i kind of get carried away on seemingly little things...


rgds,

ron g

 

[rkg22]

Hi Folks -


here's a quick and quite short list of stuff to come -


1 - DVD Burner Unit For MDR-513 IS Compatible With Philips DVDR-3576.


2 - Companion Main PCB ( comes with above burner ) MIGHT be 3576 compatible with modifications ( probably including the need to switch to a MAG remote ).


3 - MDR-513 SATA Adapter Board IS compatible with DVDR-3576 ( with minor power connector mods ).


4 - Possible BRUTE FORCE extension for memory retention due to power loss.


5 - Add A Front Panel Controller Reset Switch For Machines That Get Locked Up & Unresponsive To Remote And Front Panel Control.


Any other brave souls out there who have done mods, or have ideas for mods, post away...


rgds,

ron g

 

[rkg22]

Hi folks...


Several years back, I purchased 3 ( not all at the same time ) Philps DVDR-357x series DVD recorders. While all of these units were ultimately replaced due to tuner issues, and I ended up with 3 DVDR-3576 machines.


Recently ( mostly from reading wajo's thread, but also due to my insecurity about obsolesence ), I decided to purchase a spare DVD burner unit to have on hand in case of failures. I used the contact info for Funai in wajo's thread, but was advised by Funai that burner units were no longer available for my 3576 machines. While this information ultimately turned out to be false, I went ahead and order up a replacement for the Mag MDR-513, in hope that the burner unit would be compatible.


So the burner and its companion main PCB arrived and I went about testing the thing.


The burner unit IS a different model than the original 3576 unit, but it does fit both physically and electrically into the 3576.


Several tests confirmed that the 513 burner unit IS compatible with the 3576 hardware and main PCB.


Note that even though the burner unit is capable of higher burn speeds than the original, the ability to take advantage of the higher speeds comes from within the companion main PCB. In a nutshell, this means that you won't gain burn speed with the 513 burner unit bolted up to a 3576 main PCB. Other than this issue, the burner works fine in my 3576.


One side note, here. The 3576 burner unit has a metal tab mounted at the right front area of the drive, which makes electrical contact with the top cover. This is used to complete a metal ground shield contact for the top cover.


Interestingly enough, the MDR-513 that I have does NOT have this tab installed. Apparently Funai did not think it was necessary, so they decided to cut some costs, I suppose.


While it doesn't seem to be much of an issue, I can believe that it could be a source of noise or interference in terms of operational hiccups, so I'm keeping this in the back of my mind as time goes on.


For reference, I have not been able to confirm whether or not the Mag 513 main PCB can be made to be compatible with the balance of the 3576 hardware, but I intend to persue this further.


rgds,

ron g

 

[profhat]



Quote:
Originally Posted by rkg22 /forum/post/21664264


Hi folks...


For reference, I have not been able to confirm whether or not the Mag 513 main PCB can be made to be compatible with the balance of the 3576 hardware, but I intend to persue this further.

Awesome

 

[rkg22]

in order to delay inevitable obsolesence, i ordered and tested the Funai SATA Adapter board for the Mag-513 in my Philips 3576 units.


the adapter board WILL work properly in a Philips 3576 PATA unit.


the board is available from Funai for $12.36.


this board is designed for the Mag 513 and, as such, DOES require a bit of modification to work in the Philips machines.


Specifically, the SATA board is equipped with an on-board power connector designed to fit the power connector cable in the 513.


In order to make the proper power connections from the 3576, one can either seek out ( probably from digikey ) a new connector to install on the Philips power cable, or ( what I did ) install a short power jumper cable with a standard disk drive compatible mating power connector to utilize the existing Philips cable HDD power cable connector ( see photo ). Doing the short power jumper cable provides maximum flexibility for using both PATA and SATA drives in the Philips 357x machines.


if one installs a new SATA disk drive, the SATA board is a direct replacement for the existing Philips PATA drive interface board. the SATA board does all of the conversion from PATA to SATA. such conversion is NOT handled on the main PCB that comes with a 513 replacement DVD burner.


while conversoin to SATA can be accomplished with various aftermarket adapters, i find that using the Funai board represents a cleaner conversion.


rgds,

ron g

 

[rkg22]

there are times when the Philips 3576 will lock up and NOT be responsive to either front panel or remote control operation. for me, this usually happens during editing of material on the hard drive, and the only recovery method is to either unplug the unit from AC power for a few moments, or reset the controller using its on-board reset switch.


my DVDR installation makes it a major nuisance to pull AC power, so i elected to install a front panel controller reset switch, sacrificing the machine's DV input connector, since i never use it.


installation is a bit involved, but pretty straightforward, and results in a convenient ' front panel ' method to reset the controller and restore normal functionality to the machine.


note that resetting the controller will NOT affect configuration or channels stored, but WILL kill current date / time, as well as programmed timers.


the mod requires the following parts -


1 - small momentary pushbutton switch ( normally open contacts ).


2 - short length of 2 conductor wire cable.


3 - small rectangular panel ( made from either plastic, perf-board, or even a small piece of metal ).


the modification is accomplished as follows -


1 - carefully remove the unit's plastic front panel. this panel is held to the chassis with several small plastic tabs. gently lifting these tabs will free the front panel from the unit's chassis.


2 - unplug the DV input cable from the unit's main PCB ( see photo ).


3 - remove the 2 philips screws holding the DV input connector to the front of the unit's chassis, and remove the connector / cable from the unit.


4 - using the chassis as a fitting guide, fashion a small replacement flat panel from whatever panel stock you have chosen, drilling holes to accomodate the 2 mounting screws and whatever pushbutton switch you have chosen to use. i bought my switch from radio shack, which sells a package of pushbuttons for a few dollars, containing 4 pushbuttons.


5 - mount your pushbutton onto the flat panel you fashioned in step 4.


6 - mount the panel-switch assembly onto the chassis in the place vacated by the DV input socket, using the 2 philips screws that held the DV input connector in place.


7 - finally, solder the pushbutton contacts onto the board mounted pushbutton switch using the short piece of 2 conductor cable. this will put an extra pushbutton ' in parallel ' with the existing on-board reset pushbutton.


8 - re-install the front pael assembly to complete the mod.


i've attached several photos to show areas of pertinence.


rgds,

ron g

 

[rkg22]

I'm currently still fidgeting with an elegant solution to allow more than one of the same DVR to be individually controllable...


So far, i've attempted to skew the ~36kHz carrier up to ~38kHz, but with no success. It would appear that the IR receiver in the Funai units is sufficiently wide in bandwidth so as to continue to receive the skewed carrier...


I also tried really banging the carrier up to about 56kHz. while this would work in theory, the remotes use the same ceramic resonator to derive both the carrier AND the data rate. So skewing that far also skewed the data rate beyond spec, and the data could not be decoded...


oh well...


a senior moment had me try out a couple of cheap polaroid lenses to see if they might block cross-polarized IR light, but the lenses would not block the IR even at perfect cross polarization. again, while this would work in theory, the polarizer lenses made for the IR region of the spectrum are way cost prohibitive to consider.


it might take a bit of time ( resources ), but i plan to build up a small board that has a narrowband PLL, and utilize it to ' gate ' the existing IR receiver in these machines... essentially, a narrowband ' squelch ' that only works at 38kHz.


the remote command processor of these machines appears to function with either the original 36.7kHz carrier, or the skewed 38kHz carrier.


with a narrow enough bandwidth, switching to 38kHz on one of two identical machines might be sufficient to separate them into individually controllable units...


more later, assuming i don't pull my hair ( what i have left ) out first...

 

[rkg22]

hi folks...


ok, i've finished up trying to make the Mag Main PCB function with the Philips 3576 Motherboard and it failed.


there is some incompatibility, here, probably on the Main PCB itself, as opposed to the motherboard. In addition, the Philips power supply was straining on power up, so it may not be able to drive the main PCB with sufficient power.


in any case, sorry but no go...


do remember, though, that the DVD burner drive that comes with the MDR-513 kit DOES function properly in a Philips 3576.


rgds,

ron g

 

[7558037]

Main PCB has Mag FW which the Philips doesn't like?

 

[rkg22]



Quote:
Originally Posted by wajo /forum/post/21880190


Main PCB has Mag FW which the Philips doesn't like?

hi wajo..


well, not so sure, but i suppose it's possible. the motherboard does have some small differences electronically, so it is feasible..


the interface pathways are all the same... so at least the communications processes between the boards should work... i'm wary of my test a bit still, because i had previously modified the edge of the 1 connector in order to accomodate the Mag's use of a 28 pin header ribbon instead of the Philips' 30 pin header cable. you'll recall that in my first test, i had discovered the non-use of 2 connections on the philips cable, which would coincide with funai's adoption of a 28 pin for minor production changes or some such thing...


in my original test, there was no laboring power supply ( switcher singing due to load ), and the display did come to life.


in the latest test, i repaired the modification with a bit of hot glue and actually trimmed the philips 30 pin header cable down to 28 pins and folded the 2 unused pins back in order to make sure that the ribbon properly seated.


in the latest test, the display did not fire up.


i'm thinking that a possibility might be that the Mag might want to pass data on the equivalent of pins 2 - 29 instead of pins 3 - 30 ( the 2 outer pins not being used, as opposed to 2 pins on the end ).


i may revisit this one more time when i have a chance.


it's interesting to note that both the mag's main pcb and the philips' motherboard are silk screened for BOTH connector sizes, implying that the boards should actually talk to each other regardless, as long as the connection line-up is correct.


i wish i had a service manual for the 3576 ( as well as a scope for that matter ) so i could trace out the connections visually to see the differences... the 30 pin ribbon is soldered ( not socketed ) to the philips motherboard, so the most elegant modification is to trim the ' main pcb ' end of the ribbon such that it physically fits.


the service manual would provide an answer to the ribbon line-up question.


rgds,

ron g

 

[rkg22]

ok, so i've reviewed the service manuals for both machine types, with a focus on the ' incompatible ' ribbon cable ( 30 pin Philips versus 28 pin Mag ) and have ascertained the reason for the difference, as follows -


pins 1 & 2 on the Philips 3576 cable feed a Video Y Signal and its associated Ground over to the motherboard. this signal is processed by an IC that is NOT present on the Mag motherboard. this signal is then fed to the Video Y output of the S-Video connector on the back of the machine.


on the Mag machines, instead of this signal being used to feed that IC and subsequently to the S-Video socket, the signal is no longer used, and the Video Y source signal is tapped on the motherboard from the Video Y signal that is fed to one of the Component Video RCA jacks, and is then fed to the S-Video socket...


bottom line is that this 30 pin to 28 pin difference would render the Video Y signal at the S-Video socket to be dead without physically jumpering that signal from the Component RCA socket over to the S-Video socket.


so, while less than elegant, this particular portion of incompatibility can be rectified with little impact if the rest of the functions can be made to work.


i'm still analyzing other differences, so i still don't have a good answer yet for overall compatibility, beyond the fact that trimming the Philips 30 pin cable down to 28 pins should work ok, and it is NOT what is causing my test failures so far.


more later.


rgds,

ron g

 

[rkg22]

hi folks...


well, i've been pretty busy with other stuff ( sorry about that ), but thought i'd pass along something i read in another thread ( can't remember specific thread ) about finnicky DVD reading ( and possibly writing ) on some DVDR's ...


i believe the post i saw was regarding a sony or some other unrelated DVD transport. the post mentioned a grub screw on the drive's sled assembly that would be subject to misalignment due to wear or simple misadjusment...


the adjustment proported to change the angle of the sled, ultimately changing ( to some unknown degree ) the attack angle of the laser assembly.


it would seem to be logical that such attack angle, if not correct, might render difficulties ( either random or consistent ) in reading or even writing to some DVDs ...


the poster apparently dealt with adjustment of this thing, which corrected his/her machine's DVD read troubles...


the reason i'm even mentioning it is because i have 3 Philips 3576's, of which one tends to hiccup a bit more than the other two for no apparent reason.


my thought is that maybe this ' attack angle ' thing varies across our machines. i have not inspected the DVD transport in these machines closely, and don't even know if there is such a thing on our units, but i intend to do so forthwith, and will report any findings here...


my initial inspection will be on the spare Mag 513 transport that i have in a box, simply because it's not in service and can be looked over conveniently...


on other fronts, i've pretty much decided that a Mag main pcb will not ( at least not easily enough for me ) work in the 3576 units. there are just too many variables to consider beyond the ribbon cable issue...


rgds,

ron g

 

[DigaDo]



Quote:
Originally Posted by rkg22 /forum/post/22023914


hi folks...


well, i've been pretty busy with other stuff ( sorry about that ), but thought i'd pass along something i read in another thread ( can't remember specific thread ) about finnicky DVD reading ( and possibly writing ) on some DVDR's ...


i believe the post i saw was regarding a sony or some other unrelated DVD transport. the post mentioned a grub screw on the drive's sled assembly that would be subject to misalignment due to wear or simple misadjusment...


the adjustment proported to change the angle of the sled, ultimately changing ( to some unknown degree ) the attack angle of the laser assembly.


it would seem to be logical that such attack angle, if not correct, might render difficulties ( either random or consistent ) in reading or even writing to some DVDs ...


the poster apparently dealt with adjustment of this thing, which corrected his/her machine's DVD read troubles...


the reason i'm even mentioning it is because i have 3 Philips 3576's, of which one tends to hiccup a bit more than the other two for no apparent reason.


my thought is that maybe this ' attack angle ' thing varies across our machines. i have not inspected the DVD transport in these machines closely, and don't even know if there is such a thing on our units, but i intend to do so forthwith, and will report any findings here...


my initial inspection will be on the spare Mag 513 transport that i have in a box, simply because it's not in service and can be looked over conveniently...

The laser assemblies I've examined have the lens loosely suspended to allow for limited movement during reading and writing. Perhaps that might have something to do with an "attack angle." This suspension design would seem to discount notions of a fixed adjustment.


The first photo shows the Funai DVD Drive from a 2005 Symphonic WFR205 DVD Recorder/VCR combo.


Panasonic DVD Drives have a similar design. The second and third photos show the DVD Drive from a 2006 DMR-ES15 DVD Recorder.

 

[morc258]



Quote:
Originally Posted by rkg22 /forum/post/22023914



i believe the post i saw was regarding a sony or some other unrelated DVD transport. the post mentioned a grub screw on the drive's sled assembly that would be subject to misalignment due to wear or simple misadjusment...


the adjustment proported to change the angle of the sled, ultimately changing ( to some unknown degree ) the attack angle of the laser assembly.

I never really looked at these to that depth, but here is a Liteon DVD burner I had in my stash. These screws are clearly used for adjusting/fixing the angle of the pickup assembly. The small circle has the pivot point, and the large circle has the jack screw.

 

[rkg22]

hi guys...


thanks to both of you for those photos... it seems that the loosely mounted laser assembly might have a basis in management of vibration, overall.


i know the laser itself can move up and down ( providing calibration of spot focus during normal ops )... my thought is that these adjustments may be quite important when it comes to consistency across both the machines, and the media they are trying to read or write ... i'm guessing that maybe this ' angle deal ' , if not set within some min/max criteria, would skew the actual focus of the laser spot in one or another plane... kind of like an ' astigmatism ' adjustment on a scope, eg, focus can be had either in vertical or horizontal planes, but not both if the astig is out of kilter....


in the case of these machines, the result might be an ' oblong ' laser spot, making read or write ops a bit unreliable...


orrrrrrrrrr, i could be barking up a stupid tree, but the logic seems sound, in theory. whether or not the design process cares about a bit of ' oblongedness ' is anyone's guess, at least from my limited knowledge standpoint...


nevertheless, if i find that our machine transports have this adjustment doo-dad, i will experiment with my finicky machine to see if small adjustments renders some traceable improvement....


my finicky 3576 machine ( call it #1 ) tends to hiccup with a DVD-RW that has been burned on a different 3576 ( call it #2 ) in 2 areas...


1st, during a playback, i've noted the occasional freeze up, that recovers after a few seconds, and the playback continues...


2nd, when i attempt to erase the #2 burned disc, i almost invariably get an erase failure ( with associated error display )... after i do a quick 5 to 10 second manual record to that disc ( adding a 2nd short title ) using the #1 machine, i can then erase the disc successfully and without issue...


maybe some combination of data bits at the tail of the original title is such that ecc cannot recover somehow, causing the machine to think it can't successfully deal with the disc at hand...


i'm hoping that maybe the finicky #1 machine has this ' angle of the dangle ' issue that might clear up with a bit of nudging... if so, then this kind of thing could be at least a partial answer for folks having nuisance things like this happening with their machines...


more as i dig into this...


thanks again for inputs, guys...


rgds,

ron g