While measuring last time, I replace heatsink of PQ5EV3 - since as you noticed it was too smal, now I put same heatsink as JVC used for this part in their MV1 (or whatever it names) - its hybrid DVD-VHS recorder, it have about the same power supply and I saw on pic the original size of PQ5EV3`s heatsink. So now , after 6 hours of working without fan (standby mode) its only 42C !
Speaking about planar resistors - as you can see in service manual part list they are 1/16W. So, lets imagine that somehow voltage exceeds limit of 6.3v onthose capasitors - what happens then ?
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Not the R5304, R5305, and R5306. The power in those is only 1.55 mW, 0.55 mW, and 1.6 mW. 1/16 W is 62.5 mW.
Can you measure the -29V on CN5301, pin 3? I do not think it a problem but there may be an error in the schematic on sheet 14. Do you see D7021? It seems this is a 9.1V zener sitting between the -3.9V and the -29V supply. If this is really true then -29V may be reduced to -3.9V-9.1V = -13V. It does not seem possible because it this happened, R5314 sheet 1 would be too hot.
If the voltage becomes to high, the capacitor will start to fail. Sometimes they become open circuit. If they short, it can be very messy. They can get very hot and start to leak material. These parts create capacitance via a chemical reaction.
P.S. Good job on the heatsink
Measured - its -29v when unit is on, and -28v when unit is off. Resistor 5314 is quiet warm +45C
-3.9V, +3.9V, and -29V are only used by the display driver. I do not believe they are the source of any problems but the schematic must have an error (a missing part ).
I have traced the disposition of every active power supply voltage in power save mode and have found nothing out of the ordinary with the design.
-17V does not appear to used by the M10
AL5.3V is used only on sheet 12 ( system controller )
DC3.9(+) is used onlyby the vacuum flourescent display
DC3.9(-) same as above
-29V is used only by the display driver IC
AL-12V is used on sheet 8 ( audio section ) to supply IC8301, IC8302 and
sheet 11 ( input/output terminal section ) as power for a switch.
AL12V is only used on sheet 8 to supply IC8301, 8302, 8303, and 8202.
SW12V is used on sheet 11 to power discrete amplifiers and sheet 12 where it is divided down to +4.4V and connected to the cpu "protect" input.
SW5V is used on sheet 5, 9, 11, and 12. On 5, 9, and 11 it is used as power supply for discrete amplifiers and IC's. On sheet 12, it is used only as a clamp to prevent the cpu "protect" voltage from exceeding +5.7V
+48V is used only on sheet 12 to drive a transistor switch which holds the cpu "power_det" input low.
The only unusual findings have been that the +1.8V to the LSI processor has been set at +2.05V which has a spec. of +1.8V and that the AL5.3V has been set high as well, to +5.75V which puts it very close to the maximum rating for C7202 and C7203 on the system processor board. Other parts run hot but they should not be failing at room temperature.
I suspect the "Loading" problem is related to AL5.3V. This voltage is determined by three resistors and one IC. The other +5V power in the M10 is labelled SW5V. SW5V has its output voltage determined by only one part, a zener diode. AL5.3V only supplies the system controller which is probably the source of the "Loading" message. I hope this is the answer because the repair cost is pennies.
AL5.3V and the +1.8V to the LSI processor are the only voltages in the M10 that are determined by resistors.
Here is information regarding LSI's recommended operating voltage for a +1.8V core device.
Well, it very interesting indeed. Especialy information regarding LSi core voltage. I don`t have loading problem anyway - only green lines after long time of working. I was thinking about ways of lowing down 2v to 1.8v but I`m affraid it affects other parts those as you can see also use this voltage.
Is that D1.8V used by any other device? It seems to go from the sheet 1 to sheet 10 to sheet 5 to sheet 4 ( 8652 ) then to sheet 3. I see no devices using it except the 8652. Sheet 3 is ddr sdram but the sdram uses +2.5V.
Yes, its D1.8V. IF you trace this line, you`ll notice that it also comes to videocontroller. On sheet 4 it separating into lines (just before C1419) one goes to DMN, other goes to sheet 5 (on manual there is by mistake written to sheet 3) it goes as VDDI1.8V. On sheet 5 its first from top left comes to pins 94, 129, 150,154, 173, 149, 147, 168, 144,143, 141 & 101 of IC1001 (JSP8059) (btw I have no datasheet on it - so its a blackbox for me).
I see what you are saying. D1.8V goes from sheet 1 to sheet 10 to sheet 5 to sheet 4, then comes back out from sheet 4 as VDDI1.8. VDDI1.8 goes back to sheet 5 again and does not go to sheet 3 as shown in the manual.
This seems very odd since sheet 5 already has D1.8V. Can you confirm that JCP8059 uses +1.8V and are there any markings on JCP8059 which indicate the manufacturer?
Its not that easy - because JCP is inside the can (under metalic cover shield). And as I wrote before - shield is soldered to the board ((
Talking about 1.8v goes from one sheet to another - it doesn`t odd because in fact all those sheets - main processor, videocontroller, DDR are on one physical board, and this long lines traveling from one sheet to another and back are result of breaking one schematic into many parts ) .
It will be difficult to find out more about the JCP without unsoldering the can. I can find no information on this part on the Internet not even who makes it. Can you see if the +1.8V really goes to the can?
Regarding the "loading" comment earlier. I did not mean to say you had the problem only that it would be interesting to see what could cause it in other M10's.
Here are a few comments from other sites about it,
"Upon asking them more questions, they said that to add capacitors, they'll sauter a few more things onto the control board."
"They stated that JVC is aware of the malfunction and it is due to needing a few capacitors install to update the unit to prevent this malfunction."
From this same thread,
"POWER SAVE (off) is to blame, in conjunction with faulty resistors from what appeared to be a bad summer '04 shipment (NTSC only)."
Only AL5.3V has something in common with all these comments. It provides a +5.75VDC to two capacitors rated at only +6.3VDC located in the system controller. The value of AL5.3V is set by resistors. AL5.3V rises to its maximum voltage in "power save mode".
Ah I see now what all those resistor issues was related to! Now its clear why you tracking AL5.3V. But regarding loading problem I also read that there is ROM update took place in some cases. I will wait if green lines appers to unsoldering can and also will try to add heatsink to DMN - then I also will be able to get more information about JCP and 1.8 voltage.
We already know that +2.05V is too much for the DMN-8652. It is possible it is too much for the JCP8059 too. There are not too many modern IC's that operate on +2V. Most are +3.3, +2.5, +1.8, or +1.2V.
I was thinking if there could be a reason for why they do this. One possibility is that they are trying to share power dissipation with those IC's. The PQ5EV3 gets less hot if the output voltage is raised but the JCP8059 and DMN-8652 will get more hot. D5308, D5309, D5310 are used to lower the input voltage to PQ5EV3. This helps the PQ5EV3 get less hot but the diodes get hot.
I will wait and see if you have more information on the JCP8059 later, but I suspect this D1.8V is the bad guy in your M10.
Probably you right. But what seems strange to me that as we found 2v are normal with resistors using with PQ5EV3 - so designers had in mind that there will be exactly 2v not 1.8 shown in manual! I mean that if it is the reason then all ppl who bought M10 should have this problem if not fromt he begining then later. I only hope that this fact didn`t damage any of those huge chips!
Every IC is different. The manufacturer has a specification so that essentially all the product will work inside the specification. Outside the specification, some will have a problem but not all. Do you notice that the DMN-8652 can work successfully if the voltage is 0.18V low but it will have a problem with only 0.09V high.
I am thinking that even if the JSP8059 is designed to use +2V, it will still be safe to operate with .11V low. If this is true, the DMN-8652 will be at +1.89V which LSI says is safe and quaranteed.
I think the 8652 is an important part and it is not a good idea to operate it outside of the manufacturers recommended region.
I agree. I would like to prepare components to low down 2v to 1.8. How you suggest me to do this ?
We have spoken by email regarding DR-MV1S which I am working on solving the "Loading" issue but this forum is for M10 so I hope my suggestion is welcome. I am seeing many similarities between the two, as you would expect as pcb's are often shared between designs.
The Sw Reg /Junction pcb in DR-MV1S is a different shape to that on the M10 but the circuit is virtually identical. However bear in mind that resistor idents Rxxxx etc may vary.
I have reduced the PQ5EV3 output to +1.77V (measured) already. This was done by making R5318 (3K) resistor into 2.2k. I did this not by replacing the part, but by paralleling 7.8k across the 3k to make 2.17k which gave a theoretical voltage of 1.813V and a practical (measured) voltage of 1.77v. I also have a large TO-220 heatsink on that regulator although touching it it doesn't get very warm.
Incidentally the MV1S schematic shows R5318 as 47k but on the board is a 3.0k part. Looks like another error.
I did not have time to evaluate each change individually in true scientific style, so I have made other changes as well:
- reduce R5313 (39R 1/2W) in the fan circuit to zero ohms, to make the fan run at full speed.
- also created extra ventilation holes as the more I study this unit I think that the digital board (in shiny metal screen) is getting far too hot under prolonged use.
I also have power-save on. In conclusion I have seen "Loading" occur before but not since making the modification, and never seen green lines, but the problem I have is that when dubbing (vcr and dvd decks both in operation) the unit does not complete a disc (normally 30-60mins only) and then stops with a part-written disc which is unreadable. Good job I'm using -RW discs...
Well good job!Thank you very much for the information. But talking about my case - in M10 temperature condition when units is working are better - fan do a good job, and holes on sides near front panel make air flows through unit and hot air then removing with fan. I wonder is that metal screen on digi board is requared ? I`m not sure about that because M10 body is metalic and grounded.
Also analyzing scheme I suppose that JCP is a pack of DAC/ADCs - this is proves by different points where Vdcc applyied and logicaly where comes inputs and outputs - but I will check it for more in formation in next few days as soon as green lines appears and I will open metal shield.
Here is the equation for determining the D1.8V with present values.
V0 = 1.24 ( 1 + R5319/R5320 ) = 1.24 ( 1 + 3K/4.7K ) = 2.03V
The manual lists the part numbers for R5319 and R5320 as NRAS63D-302X and NRAS63D-472X, respectively. These are not ordinary resistors. The "D" in the p/n indicates these are 0.5% tolerance parts. Since two are used, the max. variation on this voltage will be approximately +2.03V +/-1% or +2.01 to +2.05V.
Once I found the tolerance code of these parts, I was able to determine that R5304, R5305, R5306 are also 0.5% parts.
These are considered precision parts and may be harder to find. Here is a link to one manufacturer of such parts,
The metal can is needed to prevent transmission of noise associated with fast digital parts from affecting other circuits inside the M10.
The 12VDC fan will run faster and work even if +14VDC is applied. Check the actual voltage across the fan when removing resistors. If it exceeds +12VDC, the fan will run faster but reliability will go down. The second purpose of the resistor is to limit the current drawn by the fan drive transistor in case of a short. Without the resistor, a short will blow the transistor.
Yes, I think the shiny metal screen around the digital board is excessive protection, especially for the "average domestic" environment, so if it solves some thermal problems and there are no problems caused by it (patterning on UHF television for example) then it could be removed.
trhouse, I do see what you're saying. I am looking at an MV1S of course. My unit's layout has all the tuners etc which might be sensitive, on the other side of a metal screening wall. Perhaps the screening has been over-engineered for use in certain countries, I would do that myself (I'm an RF electronics designer). I doubt the amount of EMI escaping the unit will be increased by removing the 'inner' shielding.
But if an experiment to see if thermal problems are solved by its removal proved successful, then a proper solution could be found (perhaps remove board from screen, drill lots of holes in screen, replace digital board). Small holes will still screen against the frequencies concerned due to the waveguide cut-off principle.
It is also a problem that the shiny metal screen seems to be the only means of support for the digital board. Total removal would be a problem.
On the MV1S (which may not be the case on M10) the digital board is mounted directly under the DVD drive, there's no place for warm air to rise to, it is trapped under the drive. Even the support bracket has closed-off ends and sides.
This is probably my next modification - making the DVD drive support bracket open-sided & open-ended to allow air circulation.
I also hear you that the fan going short will blow the transistor. I guess the proper protection device is a PTC thermistor/solid state fuse but a resistor is cheapest. The fan is somewhat noisy so I may well change the resistor back to a low value such as 10R when I find a full solution (while looking at the max current for the transistor concerned).
I won't be working on my unit for a few days but will still read!
It might be easier to fashion a new cover from some material such as in this link.
This material is sometimes used to make covers for switching power supplies. There is one other possible reason for the shiny metal cover. The line diodes in switching power suppies cause some big current spikes because they are on only a very short time. It was necessary for us to shield a circuit from the magnetic field created by these spikes once. The shiny metal was mu-metal which is very conductive to low frequency magnetic field. It looks shiny because of the 77% nickel content. The mu-metal could not be used to shield the power supply directly because the magnetic field was so strong that the mu-metal saturated and was ineffective, but at the longer distance it worked.
Mu-metal is 15% iron so it can be picked up with a magnet.
Originally Posted by emlsnws
Placing them directly on top of a tv set will cause the image to go all haywire, where that part of the machine comes with 5-6 inches of the tubes.
So, if this shielding is to prevent this, it's not very good. I have my DR-M10S sitting on top of a wooden desk. Compare this to an Apex DRX-9000 or a LiteOn 5001, both of which I have had sitting directly on the tv set, with no adverse side effects, each for prolonged period (6+ months).
If that is of any importance...
To be fair, my alarm clock and discman have the same affect on the tv. Cannot set either of them on top of the tv set. I actually ruined one tv from leaving an alarm clock on it for about a year. One day I moved it, and the picture turned completely purple on part of the screen. I have to leave the clock where it is, in order for the picture to look normal. I had no idea, one more lesson learned the hard way.
Those magnetic field generating by transformator in powersupply part. Same happens with alarm clock, I guess it also have 220(110) -> low voltage transformator. But you didn`t ruin your TV. All normal Tv sets have degauss system to remove magnetic from CRT mask. Usualy it works while you switching TV. If there is no scuh antimagnetic lap then there is a special devices to remove magnetism from CRT mask and other metalic things!
It is not quite the same thing. EMI stands for electromagnetic interference. emlsnws is referring to radiated interference where if the signal is allowed to radiate out of the box, it will interfere with TV and radio via the antenna or getting inside the TV and interfering with signal levels like the common 10.7 MHz IF frequency. This type of interference can be stopped with aluminum since the culprit in this case is mostly electric field. Aluminum looks like a short to electric field.
I am referring to magnetic interference which aluminum cannot block. The lower left side of the M10 is the source of low frequency magnetic field. The case of the M10 must be steel or contain some iron prevent the magnetic field from escaping into a TV. Low frequency magnetic field goes through aluminum as if it were transparent. Place a sheet of any material that a magnet can pickup under the M10 and it should help. The magnetic field does not go away but it finds an easier path though the metal so does not spread. It is like an electrical short for magnetic field. Some materials like mu-mutal are more effective shorts. See if a magnet will stick to the case of your LiteOn or Apex. If it does, it is an effective magnetic shield.
In this picture, do you see the part right above the heatsink with letters GBJ on it? That is the bridge rectifier that converts the 120VAC or 220VAC input into high voltage DC ( about 300VDC ). In doing so it creates sharp 120 Hz ( it is double the line frequency ) current spikes which are the source of the strong magnetic field.
The reason your TV is permanently affected is because most TV's have little, tiny permanent magnets around the edge of the CRT to fine tune the picture as part of the convergence process ( in addition to the ones around the neck of the crt ). These tiny magnets are immersed in the field from the M10 and have the ability to remember the field to which they were exposed after the field is removed if the exposure is sufficiently strong or long. This is the principle of the old computer "core memory".
P.S. Products like the M10 do not have transformers that operate at low frequency like 60 Hz. The way a switching power supply works is that it first converts the AC line input to a high DC voltage. The STR-G6653 then converts the high DC voltage to a high AC voltage probably at some frequency like 50 to 150 KHz. This high frequency signal is sent to a tiny transformer ( it is marked S223N in the photo and is just to the left of the heatsink ). The high frequency signal in the secondaries of the transformer are rectified to provide all the DC voltages. The advantage of this scheme, is high efficiency and small parts. Huge capacitors are needed to filter 60 Hz ripple but only tiny capacitors are needed for 50 KHz or higher.
This names pulse scheme of power supply ) Its widly used now except only Hi-Fi audio receivers imho.
So after all - I opened the can )
First of all - JCP8059 is native JVC chip ! ((
LSI chip is DMN 8652 B0 - and I measured 1.8V on control point near the chip and it is 1.86V !
Is there something wrong with the schematic? It shows the +2.03V going directly to the DMN-8652.
Originally Posted by MiG-45
There is only one other IC with a similar p/n and that is IC4001 ( p/n JCP8038 ). JVC provides more information about the 8038's function which is mostly video switching and filtering such as selecting the tuner or a front panel input.
The JCP8059 looks like it takes the DMN-8652 digital video output and converts it to analog. The DMN-8652 has its own noise processing as well described below,
As I suspected , JCP is pack of DAC/ADC convertors. It explains why i1.8 applys in different points