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fpc3
Joined: 02 Feb 2009 Posts: 31 Location: Shawnee, Kansas
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Posted: Fri Feb 06, 2009 3:38 pm Post subject: |
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Just realized I hadn't connected the P/D and the P/C leads that are labeled on the SMPS block diagram as going "to FRONT".
Do you guys know what those leads are for? I'm not sure what to tie them to. I did find voltages assigned to them at 4.2v and 4.4v. One of them also forward biases the transistor in the main PS to pickup the power relay. Do you suppose "P" stands for pulsed?... power?
Thanks.
Frank |
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fpc3
Joined: 02 Feb 2009 Posts: 31 Location: Shawnee, Kansas
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Posted: Sat Feb 07, 2009 3:12 am Post subject: |
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We got music!!!
Only problem is the DVD doesn't seem to want to open. when you push the eject button, nothing happens. Maybe too much voltage drop to the dvd player(?)
I built a power supply from a computer AT supply. Worked really well... fast and free. All I did was mount a terminal strip on the case and run the wires to it. It offers +/-12, +/-5, and +3.5 all at a bunch of current.
Frank
Fixed pix links
vtech
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fpc3
Joined: 02 Feb 2009 Posts: 31 Location: Shawnee, Kansas
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Posted: Sat Feb 07, 2009 3:35 am Post subject: |
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I messed up the picture links above... sorry...
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Sat Feb 07, 2009 4:01 am Post subject: |
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Good Work
Now you can get that IC chip from overseas that you needed from the start.
or you could Velcro/Duct tape/bungee cord the various supplies to the top of your unit.  |
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fpc3
Joined: 02 Feb 2009 Posts: 31 Location: Shawnee, Kansas
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Posted: Sat Feb 07, 2009 1:55 pm Post subject: |
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Hey Thanks JTS! Without yours and vtech's help, it wouldn't be fixed.
And you are correct. I can order the IC. I found another place in London that is lower in cost and "feels" a little better. So, I'm planning to do that. I have emailed with them a couple of times now.
Only problem I have left, is that the DVD/CD player will not respond. My hope is that the voltages are not quite right. Although they are close. I don't know if there is something more critical about the DVD/CD operation than there is in operating the AM/FM receiver portion. When I select "DVD/CD", the portion of the display that had shown "DVD/CD" goes blank. And the eject button does not open the tray. I plan to take the tray out today so that I can get to the DVD board to measure voltages.
Thanks again!
Frank |
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Sat Feb 07, 2009 2:06 pm Post subject: |
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I'd make sure DVD/CD is getting all required power sources before disassembing. You may have missed one.
If all else fails, you could always use a stand alone DVD/CD player hooked to one of the inputs on the back. |
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fpc3
Joined: 02 Feb 2009 Posts: 31 Location: Shawnee, Kansas
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Posted: Sat Feb 07, 2009 2:19 pm Post subject: |
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Yeah... I thought I had all the voltages covered before then realized I forgot a couple. And I still don't understand what the P/C and P/D are supposed to do. I don't know why they aren't just labeled with a voltage level like the other DC sources are. I just wonder if they have some AC componet in them for some reason. Or maybe they are inputs to the smps rather than outputs(??). I don't really think that is the case, but there is something unusual about them because of the way they are labeled.
And I agree. I would prefer not to have the DVD/CD player in the same box as the receiver anyway. The unit belongs to my daughter.
Frank |
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Sat Feb 07, 2009 2:25 pm Post subject: |
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Maybe when the correct IC is installed problem will go away by itself. Stranger things have happened.
I'm just saying that if you disassemble the DVD, make sure that you can reassemble it "correctly" as right now it should be "timed" correctly. |
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Sat Feb 07, 2009 2:37 pm Post subject: |
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Also if everything in the system was working correctly when it "died," then everything should be working once you resurrect SMPS.
On the other hand, if the CD/DVD was in use when the unit "died"  |
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fpc3
Joined: 02 Feb 2009 Posts: 31 Location: Shawnee, Kansas
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Posted: Sat Feb 07, 2009 4:19 pm Post subject: |
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I agree JTS... I too think the problem will go away when the smps is fixed - hopefully with the IC. And I was just thinking of removing the dvd drive as a unit... just to get to the board under it. But it seems you need to open the tray to get the front panel off. I haven't figured it out yet.
The unit failed at turn on after being off for a week. So I don't know whether the CD/DVD player would have been selected at that instant. The unit was in standby when the surge or whatever occurred. So just the smps was turned on. But the DVD board is powered from the smps voltages.
I just raised a 5.6v point up from 5.0 (5.0 was easy to get). But it made no difference. It seems all voltages are close to what they are normally except for the P/C & P/D voltages, which remain questionable. I have them set to something like 4.4vdc because they are shown as such elsewhere in the schematic. But I am wondering if there is more to those than a constant dc level.
It is a strange problem in that the display normally shows the input selected -- Whether it be FM/AM along with the freq., VCR, SAT, AUX, or DVD. But, unlike the others, when DVD is selected, that portion of the display just blanks after 2 or 3 seconds. I would think that the display circuitry would have little to do with the input selected. It's as though the display becomes dependent upon the DVD section to drive it when in that mode.
Thanks for your help and interest JTS,
Frank |
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