Re: Philips BA51RJF01021 Power Supply- How do I test it?
Furthermore, I did take the time to search the forum for other entries and all I came up with was this:
[url]https://www.badcaps.net/forum/showthread.php?t=79576&highlight=55PFL5402[/url]
I was hoping to find some schematics for the main board. No joy, but it does contain a firmware upgrade that one may find useful.Re: Philips BA51RJF01021 Power Suppl...5PFL5402[/url]
circuitmonkey
Member
Last Activity: 01-13-2021, 11:12 PM
Joined: 02-25-2018
Location: Defiance, OH
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Re: Philips BA51RJF01021 Power Supply- How do I test it?
Also, while I neglected to get any pics of the open set, I did manage to get a pic of the model info. In my defense, the was much coffee consumed this morning. Apologies....Leave a comment:
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Re: Philips BA51RJF01021 Power Supply- How do I test it?
The model is Philips 55PFL5402/F7 A. After installing the PS board, there was no response from the set. Standby mode voltages are present and I was able to follow the voltages from the power supply all the way to the power switch. The switch gets power from the LED/remote sensor board which gets power from the control board. I unplugged all the peripherals and still no difference. There was roughly 1.8V on the power switch when open and 2.3V when the switch was pressed. Further testing will have to wait until I talk to the...Leave a comment:
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Re: Philips BA51RJF01021 Power Supply- How do I test it?
Thank you for the quick reply. I connected pin 7 (P-ON-H2) to pin 15 (P-ON+21V) through a 1.5K resistor (it was the closest I could find at 5:30 in the morning) and it worked! All rails are present and correct. I will post again after I actually get a chance to put it in the unit and test it out. Learning the different methods of operation is tricky, but it is progressing. I could see from the schematic and my voltage measurements that it was in some sort of standby mode, but I honestly had no idea how to wake it up. Now it...Leave a comment:
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Philips BA51RJF01021 Power Supply- How do I test it?
I am fairly new to actually trying to repair SMPS that don't have an obvious fault, like a bad cap or burnt whatever. I am about 4 for 5 and I would really like to get this one done. It is one of the more complicated I have worked on at this point. Schematic is attached to this thread. On initial diagnostic, Q601 was blown, capacitor C615 was low capacitance high ESR. After replacing both items, powered up slow with no excessive current draw. No output voltages on the cold side. IC601 had about 130V on VH(pin 8) and nothing else. After learning a little about the PWM, I decided the lack of Vcc... -
Re: Crown Amp DC300A - One channel distirted, other good.
Just a little friendly advice. Maybe consider wiring up a dim bulb to share the current when an "oops" happens. While it won't completely eliminate damage to you or the components, it will greatly reduce the risk and in many cases mitigate damage. There are plenty of good diagrams on the Google machine. It also works pretty well as a fault tester. If you apply power and the bulb(s) stay lit, you have a significant short and no further distortion testing can really be performed until the shorts are gone. Also, without...Leave a comment:
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Re: Looking for Information on Seeburg SHP3 amplifier
Thanks!Leave a comment:
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Re: Looking for Information on Seeburg SHP3 amplifier
So the amp is finished. It actually has been finished for a few weeks,but I have been pretty busy. This amp represented the SHP I had that required the most repair. From the power supply all the way through the output signals and control boards. It was re-wired. Re-capped. All the transistors replaced, including matched transistors in the pre-amp. The bias was set (correctly) and after being tested on the bench for nearly ten hours, performed flawlessly. The customer is happy. I am happy(mostly to have it gone, but also because...Leave a comment:
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Re: Looking for Information on Seeburg SHP3 amplifier
And just because, here are the schematics for the SHFA1, SHA3, and SHFA4. Of course, the only SHFA amplifier models I have to restore are both SHFA2's....
Anyway, I scanned these up myself and so far they are better resolution than any I have seen on the net. The resolution holds up pretty well through a lrage amount of zoom, and I couldn't find anything that was illegible. So I hope someone finds them helpful....Leave a comment:
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Re: Looking for Information on Seeburg SHP3 amplifier
This PDF is for the Seeburg Digital control centers. They cover more than those listed in the file name. Check the first page of PDF for your flavor. They are more useful than some of the others I have seen and I tried my best to make them searchable. They mostly are. I think...
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Re: Looking for Information on Seeburg SHP3 amplifier
Ok, Sorry it took so long. I finally had time to get my pc talking to my scanner, so I was able to create a PDF that contained all the pages of the manual's amplifier section instead of each page on a separate PDF. I will upload more schematics as I have time to scan them. If you are looking for SS160 info, I may have the schematic. Post here to engage my rear and I'll post them....Leave a comment:
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Re: Looking for Information on Seeburg SHP3 amplifier
Ok. So I have been busy and this amp was placed to the back burner until I had a bit more time to figure this out. In my sleep deprived state, I used the wrong diodes. What Seeburg called "Stabistors" are really just two graded 1N4148 switching diodes(they were blue, and that thew me for a loop). I had one of those "Oh, duh." Moments while working in an AMI control computer board that had corroded switching diodes and realized my mistake in the Seeburg bias circuit. After replacing all four diodes, the bias...Leave a comment:
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Re: Looking for Information on Seeburg SHP3 amplifier
Also, I was under the impression these amps had been in service while owned by this customer. Turns out, he bought them because someone else "didn't have time to fix them". I.e., guessing the same guy that put the pot back together incorrectly had no idea what was wrong.Leave a comment:
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Re: Looking for Information on Seeburg SHP3 amplifier
So, it's been a minute. In fact, I forgot I posted this. I'll make a quick breakdown of what has happened. After replacing some wires with solder iron burns and thoroughly testing the driver and preamp boards, I powered it up slowly with a Variac(with a dim bulb and isolation transformer of course). Around 30 Volts, the bulbs started to glow and just as I was reaching to turn off the power a main filter cap exploded in my face. After replacing all the electrolytics, I tried it again and still had a short. Left channel output...Leave a comment:
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Re: Why do I struggle to desolder pentium 3 etc computer motherboards
Stainless steel dental pick set can be had for very cheap on Ebay and such. They are very useful in keeping tracks clear as well as manipulating component legs in hard to reach areas. I use them for both micro-soldering and point to point applications.Leave a comment:
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Re: Why do I struggle to desolder pentium 3 etc computer motherboards
The struggle is real. A couple of points that may have been mentioned but might need some clarification. The obstacle in your path to removing your components is thermal mass. The larger the mass, the more it acts as a heat sink. Increasing the heat is one way to deal with it. That can mean more wattage or increasing the efficiency of the heat transfer. Liquid flux or flux paste will aid with heat transfer. Lightly tinning the tip of your iron and wiping off the excess with a brass pad just before applying it...Leave a comment:
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Re: Looking for Information on Seeburg SHP3 amplifier
I got a hold of the customer and he will be dropping off an actual set of original Seeburg schematics. I can turn them into PDFs at that point. Should I upload them somewhere for the next guy? If so, where?Leave a comment:
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Looking for Information on Seeburg SHP3 amplifier
I have been restoring some Seeburg SHP3 amplifiers for a customer. I have repaired wiring and replaced caps and done a ton of cleaning. Not used to working on this older audio gear, so I am basically a noob. It seems pretty straight forward, but I am missing some important schematics. I have both board schematics and most of the chassis schematics. I also have a PARTIAL parts list, but no information on the resistors. I am nearly ready to power this up(on bench) and I believe the customer has all the schematics, but he is a little old school and I thought I might ask here(as you guys have been... -
Re: Replacing a cap with higher voltage, same capacitance.
Just an update: I haven't fallen off the planet. I have been building a capacitor leakage tester designed by Paul Carlson. I have a lot of caps to test on these boards and it seems to me having a good way to test for DC current leakage would be prudent. This required etching a PCB and populating. We are now at the testing and debugging stage, so I hope to have it running on the bench soon. I'll include some pics and tests when I get back to these amp boards. Thx again for all your input.Leave a comment:
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Re: Replacing a cap with higher voltage, same capacitance.
I looked into your resistor comment and you are right. It seems that metal film might be the best composition for audio resistors. Any reason I might not want to use those? I had already purchased Nichicon caps, so I'll check the signals once I restore function before I grab something a little longer lasting. I'm making some cheat sheets for quick reference as I have at least 10 of each board. It is going slow, but I took this job to learn and that I am. I appreciate all the input. Here's some more pics. Burnt/blown traces,...Leave a comment:
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