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    Sony Trinitron E450 bad contrast 15-20 minutes after turning on

    I have this CRT monitor, a Sony E450 made in 2003, that has the issue of a quite bad contrast and washed out picture after powering it on, it takes roughly 15 or 20 minutes to improve considerably but even then black levels still aren't quite ideal. This is with brightness dialed in via test pattern and contrast at 100% to get acceptable light output levels.

    Since it does improve after a warm up time is there a good chance of this being caused by capacitors and if so, what part to recap first? As far as I'm aware the vertical deflection area is where caps are stressed the most but I'm not sure if that could affect contrast as well. I haven't opened it up so far so I don't know the full cap selection yet but from the outside I see a few caps in what looks to be the power area, a Nichicon LK 450uF/470V and some smaller Rubycon YXA.

    #2
    Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

    I would start by checking the screen supply voltage cap. I believe it is in the power supply for the 220vdc (4.7µf/250vdc) Also check the caps on the 80vdc line. These supply the video output ic
    I don't have the service manual for the CPD-E450.
    Last edited by R_J; 01-25-2021, 11:13 AM.

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      #3
      Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

      CPD-E450 yeah, made in Mexico.

      OK thanks for the suggestions, I'll report back after I get to looking at those.
      Last edited by Xan03; 01-25-2021, 11:23 AM.

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        #4
        Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

        Here is the service manual, it's a low quality version but the capacitor list shows fine: https://servlib.com/sony/monitor/cpd-e450.html?start=29

        For high voltage electrolytic caps I see C524 (33uF/200V), C572 (4.7uF/250V), C573 (2.2uF/250V), C575 (33uF/200V), C621 (47uF/250V) and C622 (100uF/100V). I guess starting with those and doing a reflow on the flyback would be a start, there is also a ton of high voltage mylar and film capacitors though, do these tend to go bad as well?

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          #5
          Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

          It won't be a mylar cap that is causing this, It is likely a cap on the supplies for the video output ic.
          This is the same 19VC chassis from elektrotanya.com
          I have'nt worked on these for a very long time.
          Attached Files
          Last edited by R_J; 01-26-2021, 12:02 PM.

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            #6
            Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

            I've taken the cover off and identified a few caps; 100uF/100V is Rubycon MHE, 47uF/250V, 33uF/200V and 100uF/200V (can't find that one in the list for some reason) are Rubycon YXF. The 25V and lower ones are mostly Elna and some Rubycon YK.

            I'd replace all the high voltage ones since I've no idea which could be connected to the video output IC. I can source Panasonic ED-A for those, I think that's fine given that YXF wasn't that low ESR.

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              #7
              Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

              What equipment do you have for checking this monitor? do you have a multimeter? If you do, have you checked any of the voltages from the power supply?

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                #8
                Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                I have just a multimeter but usually try to avoid poking inside a live CRT. How easily are the test points for voltages accessible?

                Comment


                  #9
                  Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                  Originally posted by Xan03 View Post
                  I have just a multimeter but usually try to avoid poking inside a live CRT. How easily are the test points for voltages accessible?
                  One fault I've seen on Trinitrons from this era was bad power supply filter capacitor for the CRT heater. Usual symptom will be a dim or dark display. Not sure if that describes your symptoms. Heater should be 6.3 volts.

                  Probing live CRTs can be tricky (don't slip!) The service manual has a diagram (1.3) showing the main board in the "service position." The CRT neck pins should be accessible. You can probe the heater and cathodes with a DMM or oscilloscope. The grid/focus/screen pins are high-voltage, high-impedance. You can't probe them with a regular DMM or scope. Anode is 25kV.

                  One technique is to solder a well insulated wire to your test points while monitor is unplugged. Clip your meter to the wires. Then power up and measure. This is safer, less prone to slipping meter leads, and frees up your hands for other tasks.

                  Edit: Any, or many, electrolytic capacitors in a monitor this old could be bad. Look for bulging capacitors, leaking capacitors, corrosion, etc. The usual. Maybe replace them all. Even those little 1 - 10uF electrolytics can leak or dry out and go bad. I am working on an older trinitron right now, It has many bad and leaking caps. I might make a new topic about it.
                  Last edited by Ken256; 01-26-2021, 07:23 PM.

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                    #10
                    Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                    Ken256 has a good point about the heater cap (now I remember) C641 (100µf/16v) I do remember changing these quite often. C621 (47µf/250v) sounds familiar as well.
                    In fact I would replace that C641 first.
                    Last edited by R_J; 01-26-2021, 07:52 PM.

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                      #11
                      Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                      I've had my Sony Trinitron Multisync E540 since 2012, and seen it on the IT bench of a place where I used to work since 2009 or thereabouts. As far as I remember it, it's always started bright like this and then calmed down in 15-20 minutes, like you describe. There were actually two of these, and both did the same thing, so I don't think it's an age-related issue. In fact, it may not be an issue, but rather a design problem.

                      Some Sony CRT monitors did indeed have a genuine over-brightness issue caused by an additional circuit on the RGB Cut Off amp on the A board, such as the Dell P1110, P1130, and the famous GDM-FW900. Final fix for the those was detailed in post #25 of the linked thread above, or more precisely, here:
                      https://www.badcaps.net/forum/showpo...7&postcount=25

                      However, the CPD-E540 does not have that drift-correcting circuit that these monitors above do, so I'm not sure where the extra brightness at startup is coming from. Indeed it is annoying, I agree... which is why I've used mine mostly for desktop use and not as much for gaming. Not too long ago, however, I have played with the expert colors settings and have dialed it where the brightness at startup is not as noticeable. So if you want, maybe copy those on your monitor and see if that helps.
                      Contrast: 50 %
                      Brightness: 30 %.
                      Color Mode: Expert
                      R_brightness: 59 %
                      G_brightness: 72 %
                      B_brightness: 85 %
                      R_contrast: 65 %
                      G_contrast: 65 %
                      B_contrast: 65 %
                      Note that I have set my monitor to be fairly dark for mostly dark room use. As such, you'll probably want to increase the contrast to 70-80 % and brightness to maybe ~40 %. As for the individual color gains and biases listed above - my tube has a rather red hue to it. So to make it more color-neutral, I had to turn up the blue and green gains. It's still a little more red (warm colors) than normal, but I prefer it this way.

                      But apart from that, if you feel like poking in the monitor, check the B+ voltage (200V) and STBY+5V. If you have a high-voltage probe, maybe also G2. G2 is MCU-controlled on most Sony monitors, so you cannot change it through a simple pot anywhere on the monitor. You have to use WinDAS, which is what Th3_uN1Qu3 did in the fix for the P1110 and P1130. G2 is what actually makes the brightness on the tube chance, aside from the individual colors gains from the RGB amp.
                      Last edited by momaka; 01-27-2021, 04:23 AM.

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                        #12
                        Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                        Originally posted by Ken256 View Post
                        One fault I've seen on Trinitrons from this era was bad power supply filter capacitor for the CRT heater. Usual symptom will be a dim or dark display. Not sure if that describes your symptoms. Heater should be 6.3 volts.
                        Not sure, but I do have a BVM-1454D (basically PVM-1454QM) that has a quite dim picture to the point of having to both max out the contrast knob and the OSD contrast subcontrol to get acceptable light output out of it, and that's in a dark room. Could be just a worn tube as well though, as it's a broadcast monitor.

                        I'd be interested to read about your repair, there's a lack of information about CRTs now and old sites tend to get lost over time.

                        Originally posted by momaka
                        I've had my Sony Trinitron Multisync E540 since 2012, and seen it on the IT bench of a place where I used to work since 2009 or thereabouts. As far as I remember it, it's always started bright like this and then calmed down in 15-20 minutes, like you describe. There were actually two of these, and both did the same thing, so I don't think it's an age-related issue. In fact, it may not be an issue, but rather a design problem.
                        Interesting... The E540 looks absolutely identical to the E450 in terms of its cabinet and specs, I think it might just be the North American version of my monitor. I probably should have also mentioned that mine starts up blurrier than normal as well, which also takes a couple minutes to settle in, certainly longer than other CRTs I've seen as well.

                        Now that you mention those monitors I remember this fix I came across years ago, mentioned for a G500:
                        https://web.archive.org/web/20090318...Brightness-Fix

                        Might not applicable here though as the E450 is a lower-end model compared to the G500.

                        Comment


                          #13
                          Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                          Originally posted by Xan03 View Post
                          Not sure, but I do have a BVM-1454D (basically PVM-1454QM) that has a quite dim picture to the point of having to both max out the contrast knob and the OSD contrast subcontrol to get acceptable light output out of it, and that's in a dark room. Could be just a worn tube as well though, as it's a broadcast monitor.

                          I'd be interested to read about your repair, there's a lack of information about CRTs now and old sites tend to get lost over time.
                          Your BVM-1454 could have a bad cap in the heater circuit. It could have other bad caps. Very dim display is a symptom of this. There could be other issues that cause a very dim display. A bad filter cap on the heater voltage supply leads to a low voltage applied to the heater, which results in cooler cathodes and less electron emission. I have a CPD-200GS that had this problem and a few other Sonys I don't recall the models of.

                          When I repaired that CPD-200GS, I probed the CRT neck connector pins. Heater is labeled "H" or "H+". Probe DC voltage from "H" to common. It should measure 6.3 volts on most all CRTs. If it is substantially less than 6.3 volts, then there is a problem in the power supply. Trace the heater pin back to the power supply. Check the capacitor that filters the voltage for this 6.3 volt supply.

                          If that HMD-A440 service manual posted above is for your monitor, then look on pages 4-7 for the CRT connector. Page 4-12 shows the power supply. They are using a regulator for the heater supply. Older/cheaper monitors may not have a heater supply regulator.

                          As Momaka replied above, check the other main power supplies. B+, +80v, +5v, +12v, etc. Checking all the supplies to find if just one supply is bad or if there is a common problem effecting all supplies. Checking power supply function is a good starting point.

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                            #14
                            Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                            OK regarding the E450 again I did probe H on the neck board and it showed 4.94V right after powering up (using the neck board's EMI shield as ground which is hopefully fine) so you all may very well have been on the right track here. I have identified the connector with +80V, +180V etc. but due to space restrictions I can't put the board into service position so I'm not able to probe that right now. Really appreciate all the suggestions by the way, all I had done on (another) live CRT so far was turning the yoke to fix some rotation and that was scary enough to me lol.

                            I have all the capacitors specifically mentioned in this thread so far underway and since I have an Atlas ESR60 I'll be able to tell which ones were bad after replacing them. I'm assuming at least the cap in the heater circuit must be bad given the low voltage.

                            Incidentally I'm pretty sure I also have a CPD-200GS in storage that was really bad with an image far dimmer than any of my other CRTs, a greenish hue and bad phosphor smearing on dark backgrounds. Not in a hurry to try and fix that one but maybe I'll get to it one day.
                            Last edited by Xan03; 01-29-2021, 11:24 AM.

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                              #15
                              Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                              Originally posted by Ken256 View Post
                              When I repaired that CPD-200GS, I probed the CRT neck connector pins. Heater is labeled "H" or "H+". Probe DC voltage from "H" to common. It should measure 6.3 volts on most all CRTs. If it is substantially less than 6.3 volts, then there is a problem in the power supply. Trace the heater pin back to the power supply. Check the capacitor that filters the voltage for this 6.3 volt supply.
                              Not all Sony monitors have 6.3V heater.

                              The CPD-E500 has 4.9-5.0V heater, generated on the G-board (page 40 bottom-right in the service manual, IC651.)

                              I also checked the SM for my E540, and it also has a heater voltage specified at 4.9V (page 29, bottom-center, IC011 heater reg), generated on the A1 board.

                              However, the HMD-A440 SM isn't 100% clear, as voltages appear to have been mislabeled on the IC that generates the heater voltage - IC602 (BA00AST-V5), page 31, bottom-right on the D-board. If you look in the SM there, you can see that the CTL pin is labeled to have 2.9V... which is fine, because the BA00AST-V5 IC needs at least 2V on the CTL pin for the output to become enabled. Now, there are two more voltage labels: 6.3V and 1.2V. The 6.3V is pointing at GND and 1.2V pointing at OUT (which then goes to the Heater.) Obviously that's a mislabel, because 1.2V is too low for the heater. Also, the VADJ pin is the one that is expecting 1.2V, as that is the pin responsible for keeping voltage regulation (and adjustment) on the OUT pin. So if you do the math with the resistor divider formed by resistors R628 (3.9 KOhm) and R649 (1.2 KOhm), then the heater voltage really should be at around 5 to 5.1V and not 6.3V. Thus, perhaps the 6.3V is for the VCC (supply) pin? Unfortunately, Sony did not label what voltage comes out of pin 17 on transformer T601... or rather after diode D615 and C625 (25V, 2200 uF), which is what supplies IC602 with its VCC voltage that can then be used to generate the heater voltage.

                              Originally posted by Xan03 View Post
                              OK regarding the E450 again I did probe H on the neck board and it showed 4.94V right after powering up (using the neck board's EMI shield as ground which is hopefully fine) so you all may very well have been on the right track here.
                              That might actually be correct... provided the HMD-A440 service manual is the correct one for your monitor.

                              If you can't say for sure, then it might be best to trace back the heater voltage to the IC that is generating it. On these newer Sony CRT monitors, seems like a BA00AST-V5 regulator is what is used most often. Once you locate this IC and you verify that its output pin is connected to the heater pin on the CRT, measure voltage on the VCC pin (pin 2) of the BA00AST-V5 and OUT (pin 4). Also check the voltage on the VADJ pin (pin 5.) Then post back what results you get here. This should tell us if the IC is regulating properly or not.

                              Originally posted by Xan03 View Post
                              Really appreciate all the suggestions by the way, all I had done on (another) live CRT so far was turning the yoke to fix some rotation and that was scary enough to me lol.
                              Nice work... and yes, working on a live CRT like that is pretty scary indeed.
                              Mostly, it's not the high voltage that should be feared, but rather your reaction to it - that is, if you get shocked, you might yank your hand (or entire body) and accidentally cut yourself on a component on the CRT (be it a metal shield or anything else.)

                              Originally posted by Xan03 View Post
                              I have all the capacitors specifically mentioned in this thread so far underway and since I have an Atlas ESR60 I'll be able to tell which ones were bad after replacing them. I'm assuming at least the cap in the heater circuit must be bad given the low voltage.
                              I guess we will see.
                              Please come back and let us know how it went. There aren't too many topics on CRTs nowadays, so I'm sure someone looking up info on these Sony CRT monitors could find this useful.

                              Originally posted by Xan03 View Post
                              Incidentally I'm pretty sure I also have a CPD-200GS in storage that was really bad with an image far dimmer than any of my other CRTs, a greenish hue and bad phosphor smearing on dark backgrounds. Not in a hurry to try and fix that one but maybe I'll get to it one day.
                              Years ago when people were dumping out CRTs left and right, I didn't even bother to look at anything smaller than 17" most of the time.
                              However, what I find is often the case with 17" and 19" CRTs is that they have overall much better contrast than their 21" counterparts. So now I consider even 17" to be worth saving.

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                                #16
                                Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                                Thanks for the clarification on that heater voltage and additional info. The HMD-440 is a different monitor but it's the same 19VC chassis as mine as R_J had mentioned. They probably did use this PCB for different models as I've seen an unpopulated area on the board. In post #4 I linked the service manual for mine though it's a low quality version so it's hard to make out some of the diagrams.

                                For the E540, I assumed this to be just another version of the E450 as the cabinet seems to look identical, but it does mention a CR1 chassis instead so who knows... PSU on mine can take 100-240V. I'll try to keep the suggestion for probing the IC in mind for when I work on this monitor again (and hopefully can make enough space to put the board in service position).

                                I still intend to do the recap but I'm going to hold off for a while until I get a desoldering station... it occured to me that getting some of those tightly spaced caps out with just my crappy 48W iron would neither be exactly fun nor that great for the PCB.

                                Comment


                                  #17
                                  Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                                  Continuation to my last post, as I didn't submit it for some reason...

                                  *EDIT*
                                  Ah, I see the SM you mentioned now in post #4. I'll take a look and see what I can dig up out of it.

                                  Originally posted by Xan03 View Post
                                  I probably should have also mentioned that mine starts up blurrier than normal as well, which also takes a couple minutes to settle in, certainly longer than other CRTs I've seen as well.
                                  Is the contrast set to maximum? Or are RGB guns bias and gain set really high? Reason I ask is because I've seen this blurriness only when these are set too high.

                                  Originally posted by Xan03 View Post
                                  Now that you mention those monitors I remember this fix I came across years ago, mentioned for a G500:
                                  https://web.archive.org/web/20090318...Brightness-Fix
                                  Ah yes, the resistor fix/workaround.
                                  I never tried it myself but it does seem a lot easier that doing it the long (and proper) way with WinDAS software.

                                  Originally posted by Xan03 View Post
                                  Might not applicable here though as the E450 is a lower-end model compared to the G500.
                                  Well, there is a similar resistor that does the same function: R048 (2.2 MOhm, 1 Watt) on the A board (see page 26, in the upper-right corner, HMD-A440 service manual.) Looks like increasing the value of this resistor should decrease the brightness... as opposed to reducing the value of resistors, as was done for the CPD-E500 G2 "fix".
                                  And that's where things start to NOT make much sense in the HMD-A440 service manual again. G2 is shown on the A board going to the tube. Tracing back, we go through R048 and then to CN301 - which the SM says it goes to CN512 on the D board (part -c of the D board - i.e. page 30, right side of the schematic.) But then, tracing back from CN512, we see that it's connected to pin 14 on the flyback transformer (T501) and also.... GROUND! So how can ground generate 1.2 KV? Clearly something is mislabeled. (Well, either that, or could someone tell me if I am mis-interpreting something.)

                                  On the other hand, I see that G1 voltage for the HMD-A440 is generated by the flyback traffo, T501... whereas on my E540 monitor (CPD-E540), G1 pins are shown as grounded on the picture tube socket and G2 appears to be generated out of the flyback transformer, T901.

                                  So all in all, looks like there are some similarities and also some differences in these Sony monitors.

                                  Originally posted by Xan03 View Post
                                  I still intend to do the recap but I'm going to hold off for a while until I get a desoldering station... it occured to me that getting some of those tightly spaced caps out with just my crappy 48W iron would neither be exactly fun nor that great for the PCB.
                                  If it's an unregulated iron, then yeah, 48 Watts will likely make it run too hot and likely lift/burn traces off. 30-35 Watts unregulated iron will work with a good copper chisel tip, though.

                                  Or just get a soldering station, like you mentioned.
                                  On that note, go for one that uses T12 tips. If it uses M900 tips, avoid it - the cheap Chinese M900 tip clones are extremely poor quality and will hardly work at all. I have one and know the pains - it's actually much worse than my 30 Watt unregulated iron. Stations with T12 tips on the other hand - even the really cheap ones - still perform quite well.
                                  Last edited by momaka; 02-03-2021, 02:04 AM.

                                  Comment


                                    #18
                                    Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                                    It is a soldering station actually, just a really crappy one - a ZD-937 (don't know if that thing is sold under that model number worldwide). The 48W number might be just on paper anyway as I've rather had the issue of not enough heat being transfered despite setting it to 370°C, especially on newer PCBs with lots of layers and ground planes. While this CRT chassis probably doesn't quite fall under that category a desoldering gun would really make things much easier and safer in any event.

                                    Here's some pics of the (terribly dusty) inside of the E450 that I had forgotten to attach before; note the significant unpopulated area on the board and magnets attached on the tube; I wonder if that's from the factory, have not seen that on any other monitor before. And yeah, getting the chassis out and going over it with compressed air would probably be a good idea as well.
                                    Attached Files

                                    Comment


                                      #19
                                      Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                                      It is dusty but I have seen them a lot worse than that. The magnets are there from the factory to improve purity, there position and orientation are important, leave them alone.
                                      The circuit boards are manufactured for different models so all the areas are not populated.
                                      Last edited by R_J; 02-03-2021, 01:56 PM.

                                      Comment


                                        #20
                                        Re: Sony Trinitron E450 bad contrast 15-20 minutes after turning on

                                        So while I got the caps for this in a while back, for one of them I had to get a Panasonic NHG (4.7uF/400V, that heater cap apparently), and that one doesn't measure too great on the ESR60 - 4.32uF and 4.8 ohms ESR. Now since that is at 100khz maybe the ESR is normal but capacitance is a bit low for a supposedly brand new cap. Does anyone know how to read this style of Panasonic date codes? It says "87IIIDA".

                                        I have since actually found a source for Rubycon YXF but oddly everything >100V seems to be discontinued and even purged from the spec document, can't even find an old one listing those.

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